Community and International Nutrition
Intake of Micronutrient-Rich Foods in Rural Indian Mothers Is Associated
with the Size of Their Babies at Birth: Pune Maternal Nutrition Study1
Shobha Rao,* Chittaranjan S. Yajnik,†2 Asawari Kanade,* Caroline H. D. Fall,**
Barrie M. Margetts,‡ Alan A Jackson,‡ Rosaleen Shier,** Sadhana Joshi,* Sonali Rege,*
Himangi Lubree* and Bhavna Desai*
*Biometry and Nutrition Unit, Agharkar Research Institute, Pune, India; †King Edward Memorial Hospital
Research Center, King Edward Memorial Hospital, Pune, India; **Medical Research Council Environmental
Epidemiology Unit, Southampton, U.K. and ‡Institute of Human Nutrition, University of Southampton,
Southampton, U.K.
ABSTRACT One third of the Indian babies are of low birth weight (,2.5 kg), and this is attributed to maternal
undernutrition. We therefore examined the relationship between maternal nutrition and birth size in a prospective
study of 797 rural Indian women, focusing on macronutrient intakes, dietary quality and micronutrient status.
Maternal intakes (24-h recall and food frequency questionnaire) and erythrocyte folate, serum ferritin and vitamin
C concentrations were measured at 18 6 2 and 28 6 2 wk gestation. Mothers were short (151.9 6 5.1 cm) and
underweight (41.7 6 5.1 kg) and had low energy and protein intakes at 18 wk (7.4 6 2.1 MJ and 45.4 6 14.1 g)
and 28 wk (7.0 6 2.0 MJ and 43.5 6 13.5 g) of gestation. Mean birth weight and length of term babies were also
low (2665 6 358 g and 47.8 6 2.0 cm, respectively). Energy and protein intakes were not associated with birth size,
but higher fat intake at wk 18 was associated with neonatal length (P , 0.001), birth weight (P , 0.05) and triceps
skinfold thickness (P , 0.05) when adjusted for sex, parity and gestation. However, birth size was strongly
associated with the consumption of milk at wk 18 (P , 0.05) and of green leafy vegetables (P , 0.001) and fruits
(P , 0.01) at wk 28 of gestation even after adjustment for potentially confounding variables. Erythrocyte folate at
28 wk gestation was positively associated with birth weight (P , 0.001). The lack of association between size at
birth and maternal energy and protein intake but strong associations with folate status and with intakes of foods
rich in micronutrients suggest that micronutrients may be important limiting factors for fetal growth in this
undernourished community. J. Nutr. 131: 1217–1224, 2001.
KEY WORDS:
● birth size
●
India
●
maternal intake
●
food frequency questionnaire
One third of babies born in India are of low birth weight
(,2.5 kg) (Gopalan 1994, UNICEF 1998). In addition to shortterm consequences such as high infant mortality rates and childhood growth failure among survivors, low birth weight carries a
long-term risk in the form of high rates of adult coronary heart
disease and type 2 diabetes (Barker 1998). Low birth weight in
India has been attributed to widespread maternal undernutrition.
A better understanding of the relationship of birth size to maternal nutrition is critical for planning effective intervention to
improve birth weight in Indian babies.
Studies that investigated the relationship between maternal
nutrition and babies birth size are scarce, and those available
are inconsistent (Susser 1991). This relationship is influenced
by many biological and socioeconomic factors, which vary
widely in different populations. For example, the relationship
●
green leafy vegetables
differs among adolescents (Scholl et al. 1994), among women
from a low socioeconomic class (Hediger et al. 1994) and even
in most developed countries like Austria, where women have
cosmetic undernutrition (Kirchengast and Hartmann 1998).
Studies of energy and protein supplementation during pregnancy have produced varying and sometimes conflicting results (Kramer 1993), although there is some evidence that
supplementation may be beneficial in very marginally nourished women (Ceesay et al. 1997).
The dietary intakes of energy and protein of rural Indian
mothers are low (Bhatia et al. 1981, Grover 1982, Hutter
1996, Piers et al. 1995, Rawtani and Varma 1989, Vijayalaxmi
and Lakshmi 1985, Vijayalaxmi et al. 1988). The consumption
of foods that are important sources of micronutrients, such as
dairy products, meat, fresh fruits and green leafy vegetables
(GLV),3 is also low in rural Indian populations (Gupta and
Sharma 1980). Rural Indian women are often engaged in a
1
Supported by the Wellcome Trust, London, U.K., and the Medical Research
Council, U.K.
2
To whom correspondence should be addressed at Diabetes Unit, King
Edward Memorial Hospital, Rasta Peth, Pune, Maharashtra, India 411 011. E-mail:
diabetes@vsnl.com
3
Abbreviations used: BMI, body mass index; FFQ, food frequency questionnaire; GLV, green leafy vegetables; ICMR, Indian Council of Medical Research;
MUAC, mid-upper arm circumference.
0022-3166/01 $3.00 © 2001 American Society for Nutritional Sciences.
Manuscript received 5 April 2000. Initial review completed 28 July 2000. Revision accepted 2 January 2001.
1217
RAO ET AL.
1218
high level of physical activity (Piers et al. 1995). The majority
of previous studies in India have examined maternal diets in
terms of quantity (macronutrients) using 24-h recall method
but rarely assessed quality (micronutrients). Food frequency
questionnaires (FFQ) that are likely to offer estimates of habitual intake have rarely been used in studies of pregnant
women.
The assessment of maternal nutritional status requires the
measurement of body composition (before and during pregnancy), determination of energy intake and workload, measurement of patterns of food intake, consumption of macronutrients and micronutrients and biochemical measurements
of micronutrient status. In the Pune Maternal Nutrition Study,
we set out to relate the nutritional status before and during
pregnancy of women living in rural Maharashtra, India, to the
birth weight and other measurements of their babies. We
reported earlier (Fall et al. 1999) that the size at birth is
strongly predicted by maternal prepregnancy weight and
weight gain in pregnancy. Maternal height, head circumference and prepregnancy fat mass independently predicted the
birth weight of the baby. The present report describes our
findings in relation to maternal macronutrient intakes, intakes
of micronutrient-rich foods and biochemical micronutrient
status. For biochemical micronutrient status, we focused on
folate, iron and vitamin C. Folate and iron have traditionally
been considered important micronutrients for fetal growth,
and vitamin C is crucial for iron absorption.
MATERIALS AND METHODS
Mothers
The study took place in six villages, 40 –50 km from Pune City,
and covered a population of ;35,000. Of 2675 married eligible
women (aged 15– 40 y), 2466 women (92%) agreed to participate.
Field workers visited them every month to record the date of their last
menstrual period; women who missed two successive periods were
examined with ultrasound at 15–18 wk to record sonographic gestational age (Hadlock 1990). Gestational age was derived from the last
menstrual period, unless it differed from the sonographic estimate by
.2 wk, in which case the latter estimate was used. Women entered
the study if a singleton pregnancy of ,21 wk gestation was confirmed.
Socioeconomic status was assessed using a standardized questionnaire
(Pareek and Trivedi 1964), which derives a composite score based on
occupation and education of the head of the household, caste, type of
housing and family ownership of animals, land and material possessions. The majority of women were poorly educated and belonged to
subsistence farming families. All women were given 100 tablets of
iron (60 mg) and folic acid (0.5 mg) at 18 wk gestation according to
the National Nutritional Anemia Control Program.
During the study period, June 1994 through April 1996, 1102
women reported missing periods. One hundred twelve women reported an abortion/termination, 8 had major fetal anomalies and 3
had multiple pregnancies. Fourteen had incomplete prepregnancy
anthropometry, and 168 were entered beyond 21 wk of gestation.
Thus, 797 women were studied for this analysis. Ethical permission
for the study was granted by the King Edward Memorial Hospital
Ethical Committee and by the local village leaders.
Nutritional assessment
Anthropometric measurements. Women were measured every 3
mo to record their weight, height, skinfold at four sites and head and
mid-upper arm circumference (MUAC). The last set of measurements made before pregnancy was used as prepregnancy anthropometry, and the measurements were repeated during pregnancy at 18 6 2
and 28 6 2 wk gestation.
Dietary intake. The conventional 24-h recall method was modified and made more objective by incorporating information on
portion sizes, which were weighed at each mealtime by a trained
fieldworker. Women were interviewed at 18 and 28 wk of gestation by
one of four nutritionists to record the consumption of food items in
chronological order from morning until dinnertime. At the time of
diet survey, interviewers ensured that the woman was not fasting or
had an illness and that she reported foods consumed outside the home
on the day of the visit. A database of nutritive values of foods was
generated by analyzing 288 distinct food preparations commonly
consumed in the community. Protein was estimated in dried samples
by the micro-Kjeldhal method, using the 1030 Kjeltec Autoanalyser
system (Tecator AB, Hoganas, Sweden). Fat was estimated using the
Soxlet method, in which food samples are subjected to continuous
ether extraction for 18 h (Raghuramulu et al. 1983). Carbohydrates
were estimated by subtraction. In addition to the 24-h recall questionnaire, a FFQ was administered to obtain frequency of consumption of 111 foods in 17 food categories during the preceding 3-mo
period, on an 8-point scale ranging from “never” to “more than once
daily.” The 17 food categories were beverages, chapati/roti, rice,
pulses, legumes, vegetables, GLV, chutneys, fasting foods, fruits,
meat/fish, milk products, bakery items, spicy snacks, sweet snacks,
festival foods and special foods. The food groups were mutually
exclusive.
Biochemical measures of maternal nutritional status. In addition to dietary intakes, maternal red cell folate and serum ferritin and
vitamin C concentrations were measured at 18 and 28 wk. Blood
samples were taken from fasting subjects at an early-morning home
visit. Samples were protected from light and transferred within 1 h via
motorcycle to a local village research center, where samples were
centrifuged at 1310 3 g, and the serum was separated. Samples were
transferred, at 0 – 4°C in a light-protected box, to the main laboratory
at the King Edward Memorial Hospital in Pune. EDTA samples for
red cell folate assay were diluted (1:19 by volume) with 10 g ascorbic
acid/L solution and incubated for 90 min at room temperature, before
being frozen at 280°C. An equal volume of 100 g metaphosphoric
acid/L was added to 0.5-mL serum aliquots for vitamin C assay, before
being frozen at 280°C. Samples were transferred to the United
Kingdom on dry ice. Red cell folate and serum ferritin concentrations
were measured in the Hematology Laboratory, Southampton General
Hospital (Southampton, U.K.) with radioimmunoassays (Becton
Dickinson U.K., Oxford, U.K.). Serum vitamin C concentrations
were measured at the Medical Research Council Human Nutrition
Research Center (Cambridge, U.K.) using an ascorbate oxidase–
orthophenylene diamine assay on a Roche Cobas Bio Centrifugal
analyzer (Hoffman-LaRoche, Basel, Switzerland) with a fluorescence
attachment (Vuilleumier and Keck 1989).
Physical workload assessment
The women’s typical daily physical activity was recorded at 18 and
28 wk gestation using simple numeric measures in a specially designed
activity questionnaire, which included farming and domestic activities. For example, domestic activities, such as cooking and washing
clothes/utensils, were recorded in terms of the number of people
catered for, whereas fetching water was recorded in terms of the
number of trips and number of containers carried. Using published
data on the energy cost of various activities (Bleiberg et al. 1981 and
1980, Lawrence et al. 1985), a weighted total daily score was derived.
This score reflected as a base unit, an activity level of 1 kcal (4.184
kJ)/min for a 30-min slot of time. The questionnaire was validated in
41 women using a 1-d minute-to-minute observer maintained records.
Activity scores obtained by questionnaire were significantly correlated (P , 0.05) with actual time spent in domestic (r 5 0.34) and
farming (r 5 0.56) activities. The total scores were used to rank
women into tertiles of “low,” “medium” and “high” physical activity.
Neonatal anthropometry
Babies were measured by one of five trained fieldworkers within
72 h of birth. Birth weight was measured to the nearest 50 g using a
Salter spring balance (Salter Abbey, Suffolk, U.K.); crown-heel
length was measured to the nearest 0.1 cm using a portable Pedobaby
Babymeter (ETS J.M.B., Brussels, Belgium). Triceps and subscapular
skinfold thicknesses were measured to the nearest 0.2 mm, on the left
MATERNAL DIET AND BIRTH SIZE IN RURAL INDIA
1219
side of the body, using Harpenden skinfold calipers (CMS Instruments, London, U.K.). Occipitofrontal head circumference and
MUAC were measured to the nearest 0.1 cm using Fiberglas tapes
(CMS Instruments, London, U.K.). Abdominal circumference was
measured at the level of the umbilicus in expiration. Placental weight
was recorded to the nearest 5 g using Ishida scales after trimming of
the umbilical cord and membranes. Interobserver and intraobserver
variation studies were conducted every 3 mo to ensure quality of these
measurements.
weight of ,38 kg, and 9% were shorter than 145 cm, considered high risk for low birth weight (Gopalan 1989). Of the
women, 31.3% had a body mass index (BMI) of ,17 kg/m2,
indicating severe chronic energy deficiency (World Health
Organization 1995). Weight gain during pregnancy was 2.1
6 2.8 kg up to 18 wk and 5.5 6 2.9 kg up to 28 wk. All
measurements except maternal MUAC showed a significant
increase up to 28 wk’ gestation.
Statistical methods
Babies
Differences between group means were tested using t tests. Multiple regression analysis was used to examine trends in birth size
according to maternal dietary intakes and biochemical data and to
assess the relative contributions of other factors to the variability in
birth measurements. In regressions, birth measurements, maternal
measurements, energy and macronutrient intakes and erythrocyte
folate, vitamin C and ferritin concentrations were analyzed as continuous variables. Intakes of specific foods based on the FFQ and
socioeconomic and activity scores were analyzed as grouped variables.
However, when using the regression analysis, we weighted these
groupings to reflect as closely as possible the frequency of consumption per week. All analyses were adjusted for the baby’s sex, gestational age at delivery and maternal parity. Maternal and neonatal
skinfold measurements were skewed and required log-transformation
to satisfy assumptions of normality. Analysis was carried out using
SPSS/PC1, Version 5.0. Values unless otherwise stated are means
6 SD.
The full-term birth weight was 2665 g (Table 1), and 28%
of babies were of low birth weight (,2500 g). Even among
full-term babies, birth weight increased with gestational age (r
5 0.36). Birth weight, length and head circumference were
greater in boys than in girls (P , 0.01). All measurements
except length, head circumference and MUAC were smaller
in babies born to primiparous than in babies born to multiparous mothers (P , 0.05). In our analysis of birth size in
relation to nutritional data, we therefore adjusted for gestational age at delivery, baby’s sex and maternal parity.
RESULTS
Of the 797 women in the study, 12 had spontaneous abortions, 14 had late terminations and 1 died of pregnancyinduced hypertension. Seven hundred seventy infants were
delivered, of whom 8 were stillborn, 9 had major anomalies
detected at birth and 51 did not have birth measurements
within 72 h. Thus, of 702 of normal live births, our analysis
relates to 633 full-term infants.
Mothers
The mean age of the mothers was 21.4 y, and 31.6% were
primiparous. They were short, light and thin (Table 1).
Twenty-three percent of the women had a prepregnancy body
Dietary intakes
Macronutrients (24-h recall). Maternal energy and protein intakes at 18 and 28 wk were energy of 7.4 6 2.1 and 7.0
6 2.0 MJ and protein of 45.4 6 14.1 and 43.5 6 13.5 g,
respectively (Table 2). These values are low compared with
Recommended Daily Allowances for Indian pregnant women
given by the Indian Council of Medical Research (1987).
Carbohydrates were the main energy source (72%), whereas
10 and 18% of energy was derived from protein and fat,
respectively. Most protein was derived from cereals and pulses.
Only 38% of women consumed animal protein, which contributed only 15% to the daily protein intake. Activity scores
at 18 wk gestation were high (82.3 6 21.0), especially among
women from farming families, and remained so at 28 wk
gestation (76.6 6 23.2).
The birth weight of babies was not related to maternal
energy intakes, proportion of energy from animal products or
physical activity at 18 and 28 wk gestation. Because energy
intake and physical activity were interrelated (r 5 0.24, P
TABLE 1
Anthropometric measurements of the rural mothers before pregnancy and at 18 and 28 wk gestation
and of their full-term babies1
Maternal anthropometry
Parameter
Weight, kg
Height, cm
BMI,3 kg/m2
Head circumference, cm
MUAC, cm
Skinfold, mm
Subscapular
Triceps
Biceps
Suprailiac
Placental weight, g
Prepregnancy
(n 5 633)
18 wk gestation
(n 5 633)
28 wk gestation
(n 5 594)
41.7 6 5.1
151.9 6 5.1
18.1 6 1.9
52.3 6 1.5
22.5 6 1.8
43.8 6 5.0
—
18.9 6 1.8
—
22.3 6 1.7
47.3 6 5.2
—
20.5 6 1.7
—
22.7 6 1.7
10.9 6 4.0
8.9 6 3.5
4.3 6 1.8
10.0 6 5.2
—
12.4 6 4.1
9.2 6 3.3
4.3 6 1.7
13.2 6 5.8
—
13.6 6 4.4
9.8 6 3.5
4.6 6 1.8
15.8 6 6.6
—
1 Values are means 6 SD.
2 Ponderal index (kg/m3).
3 BMI, body mass index; MUAC, mid-upper arm circumference.
Neonatal
anthropometry
(n 5 633)
2.665 6
47.8 6
2.5 6
33.1 6
9.7 6
4.2
4.2
360.0
0.358
2.0
0.52
1.2
0.9
6 0.9
6 0.9
—
—
6 76.4
RAO ET AL.
1220
TABLE 2
Daily nutrient intake (modified 24-h recall) and physical
activity scores of rural mothers at 18 and 28 wk gestation1
18 wk gestation
(n 5 627)2
28 wk gestation
(n 5 609)2
7.40 6 2.1
45.4 6 14.1
34.9 6 14.8
7.0 6 4.7
72.1 6 5.1
10.3 6 1.0
17.5 6 4.8
7.00 6 2.0*
43.5 6 13.5*
32.4 6 14.0*
6.7 6 4.5
72.3 6 5.0
10.4 6 1.1
17.2 6 4.6
82.3 6 21.0
43.6 6 14.7
76.6 6 23.2*
43.5 6 14.6
Nutrient intakes
Energy, MJ/d
Protein, g/d
Fat, g/d
Animal protein,3 g/d
Carbohydrate, % energy
Protein, % energy
Fat, % energy
Daily activity scores4
Farming women
Nonfarming women
1 Values are means 6 SD. * Different from 18 wk gestation, P , 0.05.
2 Data were not available for 6 women at 18 wk and 24 women at 28
wk gestation.
3 This relates to the 38% of women who ate animal proteins (meat,
fish, eggs or milk products, excluding milk in tea/coffee) on the 24-h
recall day.
4 Number of farming women at 18 wk gestation was 481 and at 28
wk gestation 405, non-farming women at 18 wk gestation 146 and at 28
wk 204.
, 0.01 and 0.14, P , 0.01 at 18 and 28 wk gestation,
respectively), we examined the association of energy intakes
with birth weight after taking maternal size (prepregnancy
weight, height and BMI) and maternal physical activity into
account. There was no significant relationship. Similarly, protein and carbohydrate intakes (either absolute or as a percentage of total energy) were unrelated to birth measurements. In
contrast, higher fat intake at 18 wk gestation was associated
with greater neonatal length (P , 0.001) and triceps skinfold
thickness (P , 0.01). After adjustment for maternal size and
social status, fat intake at 28 wk gestation was associated only
with birth length (P , 0.05).
Food groups (FFQ). Of the 17 food groups assessed using
the FFQ, significant relationships with birth size were found
with GLV, fruits and milk products.
GLV. The GLV eaten frequently (more than once a week)
in this community were fenugreek leaves (57% of women),
spinach (33%), coriander (16%) and colocasia (15%). The
frequency of consumption of GLV at 28 wk was strongly
related to all birth measurements (Table 3). These relationships remained significant after adjustment for prepregnancy
weight (or height and BMI), energy intakes, physical activity
score, weight gain during pregnancy and socioeconomic status
(Table 4). An increase in frequency of consumption from one
group to the next higher group was associated with an increase
in birth weight of 19 g [95% confidence interval (CI), 8 –30]
after adjustments for all of these factors. The trend with birth
weight was stronger (value of partial regression coefficient
increased to 30 g; 95% CI, 13– 47) among the lightest mothers, those with a prepregnancy weight below the lowest tertile
(40 kg). The odds ratio for delivering a low birth weight baby
was 0.43 (95% CI, 20.12 to 0.99) in mothers who ate GLV at
least every other day compared with 1.0 in mothers who never
ate them.
TABLE 3
Relationships between frequency of rural mothers’ intakes of green leafy vegetables and fruits at 28 wk gestation and of milk at
18 wk gestation and neonatal anthropometry1
Neonatal measurement
Food group
Frequency
n
Birth
weight
Birth
length
Head
circumference
g
Green leafy
vegetables,
wk 28
P1
P2
Fruits, wk 28
P1
P2
Milk products,
wk 18
P1
P2
MUAC2
Abdominal
circumference
Triceps
skinfold
cm
Subscapular
skinfold
mm
Placental
weight
g
Never
,13/wk
.13/wk
$Alternate
days
60
175
225
2571 6 356
2601 6 341
2675 6 363
47.0 6 2.0
47.5 6 1.9
48.0 6 2.0
32.6 6 1.2
32.9 6 1.2
33.2 6 1.2
9.6 6 1.0
9.6 6 0.8
9.7 6 0.9
28.2 6 1.8
28.2 6 2.0
28.6 6 1.9
3.9 6 1.4
4.0 6 1.2
4.1 6 1.2
3.9 6 1.2
4.1 6 1.2
4.0 6 1.2
347 6 69
354 6 66
358 6 82
149
,13/wk
.13/wk
$13/d
44
363
202
Never
,13/wk
.13/wk
$Alternate
days
95
134
116
2742 6 350
,0.001
,0.005
2598 6 340
2633 6 355
2721 6 357
,0.01
0.13
2643 6 369
2618 6 356
2639 6 344
47.9 6 1.9
,0.01
,0.05
47.5 6 1.7
47.5 6 2.0
48.1 6 1.9
,0.01
0.23
47.5 6 2.0
47.6 6 2.0
47.6 6 2.0
33.3 6 1.2
,0.001
,0.005
32.7 6 1.1
32.9 6 1.2
33.4 6 1.2
,0.001
,0.01
32.9 6 1.2
33.0 6 1.2
33.0 6 1.1
9.9 6 0.9
,0.05
,0.05
9.7 6 0.8
9.6 6 0.9
9.8 6 0.8
0.09
0.80
9.6 6 1.0
9.7 6 0.9
9.5 6 0.8
29.1 6 1.7
,0.001
,0.005
28.6 6 2.0
28.5 6 1.9
28.8 6 1.9
0.15
0.45
28.5 6 2.1
28.6 6 1.7
28.5 6 1.9
4.4 6 1.2
,0.001
,0.001
4.1 6 1.2
4.1 6 1.2
4.1 6 1.2
0.44
0.38
4.2 6 1.2
4.1 6 1.2
4.1 6 1.2
4.3 6 1.2
,0.05
,0.05
4.2 6 1.2
4.1 6 1.2
4.2 6 1.2
0.67
0.99
4.1 6 1.2
4.1 6 1.2
4.1 6 1.2
371 6 81
,0.05
0.41
352 6 76
353 6 75
370 6 79
,0.05
0.07
354 6 78
348 6 79
352 6 71
2704 6 361
,0.05
0.14
48.0 6 2.0
,0.05
0.13
33.2 6 1.3
,0.01
,0.01
9.8 6 0.9
,0.05
0.11
28.8 6 2.0
0.15
0.52
4.1 6 1.2
0.90
0.48
4.1 6 1.2
0.41
0.46
371 6 77
,0.01
,0.01
281
1 Values are means 6 SD. P1 values after adjustment for sex, parity and gestational age at delivery. P2 values after additional adjustment for
prepregnancy weight, energy intake, activity, social class, weight gain up to 28 wk and relevant micronutrients and macronutrients (for green leafy
vegetables, erythrocyte folate concentration; for fruits, serum vitamin C concentration; for milk products, fat intake).
2 MUAC, mid-upper arm circumference.
MATERNAL DIET AND BIRTH SIZE IN RURAL INDIA
1221
TABLE 4
Multiple regression analysis of the relationship of the frequency of maternal intakes of green leafy vegetables, fruits and milk
products with birth weight among rural Indian women1
Green leafy vegetable
intake at 28 wk gestation
Dependent
variable
Birth weight, g
Independent parameters
Sex, parity, gestation at birth
Sex, parity and gestation at
birth plus prepregnancy
weight,2 energy intake,
activity, social status and
weight gain up to 28 wk and
micronutrients and
macronutrients3
R2
b
P
22.1
(1.8)
32.6
(1.8)
19.1
,0.001
19.4
,0.001
Fruit intake
at 28 wk gestation
R2
21.4
(1.0)
29.8
(0.34)
Milk product intake
at 18 wk gestation
b
P
R2
b
P
7.4
,0.01
6.9
0.08
4.3
0.12
20.5
(0.7)
29.4
(0.4)
4.8
0.06
1 Dietary variables were grouped (as in Table 3) and were weighted to reflect as closely as possible the consumption per week. Therefore, the b
coefficient represents the increase in birth weight associated with increased consumption of that food group by one time per week. Values in
parentheses represent the contribution of dietary variables to R2.
2 Replacement of prepregnancy weight with height and body mass index did not change the relationship (R2, b values and significance).
3 Indicates further adjustment for other variables, including micronutrients and macronutrients: for green leafy vegetables, erythrocyte folate
concentration; for fruit, serum vitamin C concentration; for milk products, fat intake. The exclusion of gestation from this regression reduced R2 values
for the three food groups to 22.0, 17.8 and 16.9%, respectively, whereas the contribution of dietary variables increased to 2.05, 0.5 and 0.4%,
respectively.
Fruits. Pregnant women had relatively high intakes of
“vitamin C–rich” fruits, which were freely available from trees
growing in the fields. These fruits included zizapus (eaten more
than once a week by 58% of women), raw tamarind (48%) and
guava (40%). The frequency of consumption of fruits at 28 wk
gestation was related to birth weight, birth length, head circumference and placental weight but not to measures of neonatal fat, MUAC or abdominal circumference (Table 3).
These relationships remained significant after adjustment for
prepregnancy weight (or height and BMI), energy intake,
physical activity score and socioeconomic score but not after
adjustment for weight gain (Table 4). Similar to GLV, relationships were stronger among lighter mothers. An increase in
the frequency of fruit consumption from one group to the next
higher group was associated with an increase in birth weight of
4 g (95% CI, 21 to 10) in the sample as a whole and 15 g
(95% CI, 6 –24) in women with a prepregnancy weight of ,40
kg (Table 4).
Milk products. Milk was consumed mostly by women
from families who owned milk-producing animals. It was consumed either with roti or rice or was drunk but rarely was
consumed in the form of other milk products. Milk consumption was strongly associated with socioeconomic score (P
, 0.001). The frequency of milk consumption at 18 wk
gestation was related to birth weight, birth length, MUAC,
head circumference and placental weight but not to measures
of neonatal fat or abdominal circumference (Table 3). In
contrast to GLV and fruits, these relationships were stronger at
18 wk’ than at 28 wk gestation. They were similar at all levels
of prepregnancy maternal weight and remained significant
after adjustment for prepregnancy weight (or height and BMI),
energy intakes, physical activity score, socioeconomic status
and weight gain (Table 4).
In all of these regression analyses, the major contribution
was from main confounding variables (gestation, sex and parity: ;20%). The contributions of dietary variables varied from
2 to 3% but were significant.
Biochemical indices of maternal nutrition
Concentrations of erythrocyte folate, serum ferritin and
serum vitamin C [median (interquartile range)] were 868
nmol/L (687–1097), 13 mg/L (8 –23) and 10 mmol/L (2–31) at
18 wk gestation and 968 nmol/L (741–1273), 10 mg/L (7–20)
and 6 mmol/L (1–22) at 28 wk gestation. All three micronutrients were related to birth size (Table 5). The strongest and
most consistent relationship was with 28-wk erythrocyte folate
concentration, which was positively related to birth weight,
birth length, head circumference, MUAC, abdominal circumference and placental weight but not to skinfold thickness.
Higher serum vitamin C concentration at 28 wk gestation was
associated with higher birth length, MUAC and abdominal
circumference (Table 5), and higher concentration at 18 wk
gestation was associated with higher MUAC (P , 0.05) and
triceps skinfold thickness (P , 0.05). In contrast, ferritin
concentration at 28 wk gestation was inversely related to birth
length, MUAC and abdominal circumference (Table 5). All
of these relationships remained significant after adjustment for
prepregnancy weight (or height and BMI), energy intakes,
physical activity, weight gain and socioeconomic status.
GLV are a rich source of folate. Higher intakes at 28 wk
gestation were associated with higher erythrocyte folate concentration (1099 nmol/L in women who ate GLV at least once
every other day compared with 949 nmol/L in those who never
ate them, P , 0.05). The relationship between intake of GLV
with birth weight remained significant after adjustment for
erythrocyte folate concentration (Table 4). Similar analysis
revealed that this relationship was also strong for all other
neonatal measurements. GLV are also a rich source of iron.
GLV intakes were not, however, related to serum ferritin
concentration. Fruits consumed by rural mothers were rich in
vitamin C, and higher fruit intakes were associated with
higher serum vitamin C concentration (19 mmol/L in women
who ate fruit at least once daily compared with 11 mmol/L in
those who ate fruit less than once a week; P , 0.05). The
relationship of fruit intake to birth weight was not significant
(P 5 0.13) after adjustment for serum vitamin C concentra-
RAO ET AL.
1222
TABLE 5
Relationship’s between rural mothers’ erythrocyte folate, serum ferritin and serum vitamin C concentrations at
28 wk gestation and neonatal anthropometry1
Neonatal measurement
Blood
nutrient
Concentration
n
Birth
weight
Birth
length
Head
circumference
g
Erythrocyte
folate,
nmol/L
P1
P2
Serum ferritin,
mg/L
P1
P2
Serum vitamin
C, mmol/L
P1
P2
MUAC
Abdominal
circumference
Triceps
skinfold
cm
Subscapular
skinfold
mm
Placental
weight
g
,816
171
2616 6 360
47.5 6 1.9
33.0 6 1.3
9.5 6 0.9
28.4 6 2.0
4.1 6 1.2
4.2 6 1.2
347 6 78
816–1147
171
2637 6 369
47.7 6 2.3
32.9 6 1.2
9.7 6 0.8
28.6 6 1.7
4.1 6 1.2
4.1 6 1.2
356 6 66
$1147
172
,8
8–16
$16
162
196
185
,4
4–19
$19
254
169
146
2727 6 347
,0.001
,0.001
2695 6 362
2657 6 350
2649 6 378
0.20
0.18
2647 6 343
2679 6 353
2688 6 396
0.23
0.29
48.1 6 1.8
,0.05
0.08
47.7 6 2.0
47.8 6 2.0
47.7 6 2.1
,0.05
,0.05
47.6 6 2.0
47.8 6 2.0
47.9 6 2.0
,0.05
0.07
33.3 6 1.2
,0.05
0.12
33.1 6 1.3
32.9 6 1.2
33.2 6 1.3
0.85
0.86
33.0 6 1.2
33.1 6 1.2
33.1 6 1.3
0.70
0.70
9.8 6 0.9
,0.005
,0.01
9.8 6 0.8
9.7 6 0.8
9.6 6 1.0
,0.01
,0.01
9.7 6 0.8
9.6 6 0.9
9.8 6 1.0
,0.01
,0.05
28.9 6 1.9
,0.005
,0.01
28.9 6 1.7
28.6 6 1.8
28.5 6 2.1
,0.05
,0.05
28.5 6 1.9
28.7 6 1.7
29.0 6 2.1
,0.01
,0.05
4.2 6 1.2
0.19
0.26
4.2 6 1.2
4.2 6 1.2
4.1 6 1.2
0.18
0.28
4.1 6 1.2
4.2 6 1.2
4.2 6 1.2
0.07
0.15
4.1 6 1.2
0.64
0.79
4.2 6 1.2
4.1 6 1.2
4.1 6 1.2
0.22
0.25
4.1 6 1.2
4.1 6 1.2
4.2 6 1.2
0.59
0.75
374 6 83
,0.001
,0.001
361 6 76
364 6 65
355 6 90
0.21
0.15
356 6 75
360 6 79
367 6 78
0.92
0.84
1 Values are means 6 SD. P1 values after adjustment for sex, parity and gestational age at delivery. P2 values after additional adjustment for
prepregnancy weight, energy intake, activity, social class and weight gain up to 28 wk gestation.
tion (Table 4) but remained significant for head circumference. Similarly, milk was a major contributor (29%) to total
fat intake, and after adjustment for fat intakes, the relationship
of milk consumption with birth weight (Table 4) was not
significant (P 5 0.10) but remained significant for neonatal
length (P , 0.005) and triceps skinfold thickness (P , 0.01).
DISCUSSION
We studied the size of rural Indian newborn babies in
relation to their mothers’ diets and circulating micronutrient
concentrations in pregnancy. The strengths of our study were
that it was community based, wherein prepregnancy maternal
anthropometry and accurate gestational age were recorded.
We also developed community-specific methods for estimating
dietary intakes objectively, and we report data on the consumption of various food groups as well as nutrient intakes.
Rural mothers were thin and short, indicating that many
were chronically energy deficient before conception. Although
their mean weights and heights were similar to those reported
from other rural areas of India (Vijayalaxmi et al. 1988), they
were significantly less than those of urban affluent Indian
(Devi et al. 1989, Gupta and Sharma 1980, Piers et al. 1995)
and Western (Godfrey et al. 1996) mothers. The neonatal size
was similar to that reported in other Indian populations (Mohan et al. 1990) but markedly smaller than that of Western
babies (Godfrey et al. 1996).
Maternal intakes of energy and protein were low, ;70 –
75% of recommended intakes (ICMR 1987) at both time
points, and showed no significant relationships with neonatal
size. For energy intakes, the lack of any relationship with birth
size was true for the whole study group, within subgroups of
maternal prepregnancy weight and after taking physical activity into account. It was also true when women with extremely
low intakes (,1.2 basal metabolic rate, n 5 150) were excluded. These important negative findings are consistent with
the slight effects on birth size of energy and protein supplementation trials in pregnancy (Kramer 1993).
Among the macronutrients, only fat intake at 18 wk gestation showed an association with birth size. Fat intake has
been shown to correlate with birth weight (Doyle et al. 1982),
but there are few data for fat reported as an entity separate
from energy. Recent studies suggest that specific fatty acids are
important for fetal growth (Crawford et al. 1989), which
brings into question whether fat is a macronutrient or micronutrient.
Birth size was strongly related to intakes of GLV and fruits
at 28 wk gestation and of milk at 18 wk gestation. These three
food groups are particularly rich in micronutrients. Our observations therefore suggest the importance of specific micronutrients, or their combinations, for fetal growth. For example,
GLV are a rich source of folate, iron, provitamin A carotenoids and antioxidants. Increased frequency of the consumption of GLV was associated with an increase in all neonatal
anthropometry, and the relationship with birth size remained
significant even after correction for red cell folate concentration in blood, suggesting that nutrients other than folate
contribute to the relationship. Similarly, fruits are rich in
vitamin C and other antioxidants, whereas milk provides high
quality proteins, fat, calcium, riboflavin and vitamins A and D.
It was interesting to note that a greater consumption of fruits
or milk was not associated with increased measures of neonatal
fat or abdominal circumference, as occurred for the consumption of GLV. Furthermore, the relationship with fruit consumption when corrected for circulating vitamin C concentration in blood did not remain significant for group as a whole
but was significant only for thin mothers. Similarly, the relationship of milk consumption after adjustment for fat intake
did not remain significant for birth weight but was significant
for length and triceps skinfold thickness. This suggests important roles of different micronutrients in improving fetal
growth.
MATERNAL DIET AND BIRTH SIZE IN RURAL INDIA
One of the causal pathways for the effect of micronutrients
could be an increase in the gestational period. The exclusion
of gestation from regression analyses in Table 4 showed marginal increase in the contribution of respective dietary variables in R2 and keeps the relationship significant. However, its
inclusion explains up to 15% of the variability in birth weight
and substantially increases the overall R2. This suggests that
the effect of micronutrient intakes on fetal growth is in part
mediated through the lengthening of the gestation.
Birth measurements were related to intakes of GLV and
fruit at 28 wk, whereas they were related to fat and milk
intakes at 18 wk. This may reflect different nutrient requirements for fetal growth at these times due to the development
of different tissues at various stages of gestation (Dugdale and
Payne 1975, Tanner 1989). The relationships of GLV and fruit
intake to birth size were strongest in lighter and thinner
women. We did not detect any significant difference in other
factors (parity, macronutrient intake, blood pressure and glycemic status) associated with fetal growth in these women
compared with the remainder of the group. It is likely that
micronutrients may be the most important limiting nutrients
in undernourished women.
We found inverse relationships between maternal serum
ferritin concentration at 28 wk gestation and neonatal size.
This somewhat paradoxical finding has been reported in other
populations (Goldenberg et al. 1996) and might be explained
by hemodilution effects due to plasma volume expansion,
which is associated with increased fetal growth (Rosso et al.
1992). Because ferritin represents a stored form of iron, an
alternative explanation is that a lower ferritin concentration
in the mother signifies the successful mobilization of iron,
making it available for fetal growth. It is interesting, in this
respect, that the inverse relationships of serum ferritin concentration were strongest with neonatal MUAC (representing
muscle) and abdominal circumference (representing viscera),
tissues with a high iron content.
To our knowledge, this study is the first to show an association between maternal intakes of GLV, fruits and milk and
size at birth . Furthermore, the significant relationship between
biomarkers (erythrocyte folate and serum vitamin C) and the
frequency of consumption of GLV and fruits, respectively,
provides a measure of confidence in our FFQ assessment.
Although we cannot assume cause-and-effect relationships in
any of the associations we have described, our data suggest that
improved maternal intakes of milk in early gestation and of
GLV and fruit in late gestation could lead to improved fetal
growth. There may be concern in attributing significance to
these foods because we had conducted multiple analyses of 17
food groups. We did, however, start with the a priori hypothesis that micronutrient-rich foods may be important for fetal
growth. If the P-value was corrected for these 17 food groups,
making P 5 0.003 the cutoff for statistical significance, the
relationship between birth size and GLV remains significant.
There is controversy as to whether food or pharmacology is
the best means of providing micronutrients (West 1996).
There is some evidence that supplementation with folate in
pregnancy leads to improved fetal growth (Baumslag et al.
1970, Ek 1982, Goldenberg et al. 1992, Iyengar and Rajalakshmi 1975). However, an evaluation of India’s long-standing
anemia prophylaxis program, with routine iron and folate
supplementation to women in the third trimester of pregnancy
for the past two decades, demonstrates no significant impact
on birth weight (ICMR 1989). It may be that the micronutrient-rich foods discussed here provide a more effective combination of nutrients than do conventional supplements that
contain only one or two micronutrients or macronutrients.
1223
Thus, food-based interventions may be more beneficial. There
are limited data from controlled trials on the effects of micronutrients on fetal growth. Most have shown a small or no
effect (Mathews 1996, Onis et al. 1998). The long-term implications of our findings that specific maternal food intakes
are related to different components of neonatal phenotype are
unknown at this stage and could be best understood by following these babies to determine infant mortality rates, childhood growth rates and long-term health. Further research, in
animals and humans, is needed to identify the important
nutrients provided by these key food groups and their mode of
action. We also believe an intervention trial should be attempted to study the effects of increased availability of these
foods for pregnant women.
ACKNOWLEDGMENTS
We are grateful to the community and to the pregnant women and
their families for their cooperation. We would like to thank David
Collis and the staff of the Special Hematology Laboratory
(Southampton General Hospital, Southampton, U.K.) for the ferritin
and folate assays and Chris Bates, Glynn Harvey and Jonathan
Perkins (Medical Research Council Resource Center for Human
Nutrition Research, Cambridge, U.K.) for the vitamin C assays. We
also thank A. D. Agate (Director, Agharkar Research Institute),
V. N. Rao (Director, the King Edward Memorial Hospital Research
Center) and K. J. Coyaji (Director, Department of Obstetrics and
Gynecology, King Edward Memorial Hospital) for providing the
facilities for this collaborative research. We acknowledge the contributions made to the study by Arun Kinare, Monesh Shah, Asit
Natekar, Manoj Chinchwadkar, Binu John, Anuja Bisht, Mahananda
Bhavikatti, Poonam Gupta, Charu Joglekar, Parveen Bharucha and
Vanessa Cox.
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Community and International Nutrition
Intake of Micronutrient-Rich Foods in Rural Indian Mothers Is Associated
with the Size of Their Babies at Birth: Pune Maternal Nutrition Study1
Shobha Rao,* Chittaranjan S. Yajnik,†2 Asawari Kanade,* Caroline H. D. Fall,**
Barrie M. Margetts,‡ Alan A Jackson,‡ Rosaleen Shier,** Sadhana Joshi,* Sonali Rege,*
Himangi Lubree* and Bhavna Desai*
*Biometry and Nutrition Unit, Agharkar Research Institute, Pune, India; †King Edward Memorial Hospital
Research Center, King Edward Memorial Hospital, Pune, India; **Medical Research Council Environmental
Epidemiology Unit, Southampton, U.K. and ‡Institute of Human Nutrition, University of Southampton,
Southampton, U.K.
KEY WORDS:
● birth size
●
India
●
maternal intake
●
food frequency questionnaire
One third of babies born in India are of low birth weight
(,2.5 kg) (Gopalan 1994, UNICEF 1998). In addition to shortterm consequences such as high infant mortality rates and childhood growth failure among survivors, low birth weight carries a
long-term risk in the form of high rates of adult coronary heart
disease and type 2 diabetes (Barker 1998). Low birth weight in
India has been attributed to widespread maternal undernutrition.
A better understanding of the relationship of birth size to maternal nutrition is critical for planning effective intervention to
improve birth weight in Indian babies.
Studies that investigated the relationship between maternal
nutrition and babies birth size are scarce, and those available
are inconsistent (Susser 1991). This relationship is influenced
by many biological and socioeconomic factors, which vary
widely in different populations. For example, the relationship
●
green leafy vegetables
Downloaded from jn.nutrition.org by guest on August 28, 2015
ABSTRACT One third of the Indian babies are of low birth weight (,2.5 kg), and this is attributed to maternal
undernutrition. We therefore examined the relationship between maternal nutrition and birth size in a prospective
study of 797 rural Indian women, focusing on macronutrient intakes, dietary quality and micronutrient status.
Maternal intakes (24-h recall and food frequency questionnaire) and erythrocyte folate, serum ferritin and vitamin
C concentrations were measured at 18 6 2 and 28 6 2 wk gestation. Mothers were short (151.9 6 5.1 cm) and
underweight (41.7 6 5.1 kg) and had low energy and protein intakes at 18 wk (7.4 6 2.1 MJ and 45.4 6 14.1 g)
and 28 wk (7.0 6 2.0 MJ and 43.5 6 13.5 g) of gestation. Mean birth weight and length of term babies were also
low (2665 6 358 g and 47.8 6 2.0 cm, respectively). Energy and protein intakes were not associated with birth size,
but higher fat intake at wk 18 was associated with neonatal length (P , 0.001), birth weight (P , 0.05) and triceps
skinfold thickness (P , 0.05) when adjusted for sex, parity and gestation. However, birth size was strongly
associated with the consumption of milk at wk 18 (P , 0.05) and of green leafy vegetables (P , 0.001) and fruits
(P , 0.01) at wk 28 of gestation even after adjustment for potentially confounding variables. Erythrocyte folate at
28 wk gestation was positively associated with birth weight (P , 0.001). The lack of association between size at
birth and maternal energy and protein intake but strong associations with folate status and with intakes of foods
rich in micronutrients suggest that micronutrients may be important limiting factors for fetal growth in this
undernourished community. J. Nutr. 131: 1217–1224, 2001.
differs among adolescents (Scholl et al. 1994), among women
from a low socioeconomic class (Hediger et al. 1994) and even
in most developed countries like Austria, where women have
cosmetic undernutrition (Kirchengast and Hartmann 1998).
Studies of energy and protein supplementation during pregnancy have produced varying and sometimes conflicting results (Kramer 1993), although there is some evidence that
supplementation may be beneficial in very marginally nourished women (Ceesay et al. 1997).
The dietary intakes of energy and protein of rural Indian
mothers are low (Bhatia et al. 1981, Grover 1982, Hutter
1996, Piers et al. 1995, Rawtani and Varma 1989, Vijayalaxmi
and Lakshmi 1985, Vijayalaxmi et al. 1988). The consumption
of foods that are important sources of micronutrients, such as
dairy products, meat, fresh fruits and green leafy vegetables
(GLV),3 is also low in rural Indian populations (Gupta and
Sharma 1980). Rural Indian women are often engaged in a
1
Supported by the Wellcome Trust, London, U.K., and the Medical Research
Council, U.K.
2
To whom correspondence should be addressed at Diabetes Unit, King
Edward Memorial Hospital, Rasta Peth, Pune, Maharashtra, India 411 011. E-mail:
diabetes@vsnl.com
3
Abbreviations used: BMI, body mass index; FFQ, food frequency questionnaire; GLV, green leafy vegetables; ICMR, Indian Council of Medical Research;
MUAC, mid-upper arm circumference.
0022-3166/01 $3.00 © 2001 American Society for Nutritional Sciences.
Manuscript received 5 April 2000. Initial review completed 28 July 2000. Revision accepted 2 January 2001.
1217
RAO ET AL.
1218
MATERIALS AND METHODS
Mothers
The study took place in six villages, 40 –50 km from Pune City,
and covered a population of ;35,000. Of 2675 married eligible
women (aged 15– 40 y), 2466 women (92%) agreed to participate.
Field workers visited them every month to record the date of their last
menstrual period; women who missed two successive periods were
examined with ultrasound at 15–18 wk to record sonographic gestational age (Hadlock 1990). Gestational age was derived from the last
menstrual period, unless it differed from the sonographic estimate by
.2 wk, in which case the latter estimate was used. Women entered
the study if a singleton pregnancy of ,21 wk gestation was confirmed.
Socioeconomic status was assessed using a standardized questionnaire
(Pareek and Trivedi 1964), which derives a composite score based on
occupation and education of the head of the household, caste, type of
housing and family ownership of animals, land and material possessions. The majority of women were poorly educated and belonged to
subsistence farming families. All women were given 100 tablets of
iron (60 mg) and folic acid (0.5 mg) at 18 wk gestation according to
the National Nutritional Anemia Control Program.
During the study period, June 1994 through April 1996, 1102
women reported missing periods. One hundred twelve women reported an abortion/termination, 8 had major fetal anomalies and 3
had multiple pregnancies. Fourteen had incomplete prepregnancy
anthropometry, and 168 were entered beyond 21 wk of gestation.
Thus, 797 women were studied for this analysis. Ethical permission
for the study was granted by the King Edward Memorial Hospital
Ethical Committee and by the local village leaders.
Nutritional assessment
Anthropometric measurements. Women were measured every 3
mo to record their weight, height, skinfold at four sites and head and
mid-upper arm circumference (MUAC). The last set of measurements made before pregnancy was used as prepregnancy anthropometry, and the measurements were repeated during pregnancy at 18 6 2
and 28 6 2 wk gestation.
Dietary intake. The conventional 24-h recall method was modified and made more objective by incorporating information on
portion sizes, which were weighed at each mealtime by a trained
fieldworker. Women were interviewed at 18 and 28 wk of gestation by
one of four nutritionists to record the consumption of food items in
chronological order from morning until dinnertime. At the time of
diet survey, interviewers ensured that the woman was not fasting or
had an illness and that she reported foods consumed outside the home
on the day of the visit. A database of nutritive values of foods was
generated by analyzing 288 distinct food preparations commonly
consumed in the community. Protein was estimated in dried samples
by the micro-Kjeldhal method, using the 1030 Kjeltec Autoanalyser
system (Tecator AB, Hoganas, Sweden). Fat was estimated using the
Soxlet method, in which food samples are subjected to continuous
ether extraction for 18 h (Raghuramulu et al. 1983). Carbohydrates
were estimated by subtraction. In addition to the 24-h recall questionnaire, a FFQ was administered to obtain frequency of consumption of 111 foods in 17 food categories during the preceding 3-mo
period, on an 8-point scale ranging from “never” to “more than once
daily.” The 17 food categories were beverages, chapati/roti, rice,
pulses, legumes, vegetables, GLV, chutneys, fasting foods, fruits,
meat/fish, milk products, bakery items, spicy snacks, sweet snacks,
festival foods and special foods. The food groups were mutually
exclusive.
Biochemical measures of maternal nutritional status. In addition to dietary intakes, maternal red cell folate and serum ferritin and
vitamin C concentrations were measured at 18 and 28 wk. Blood
samples were taken from fasting subjects at an early-morning home
visit. Samples were protected from light and transferred within 1 h via
motorcycle to a local village research center, where samples were
centrifuged at 1310 3 g, and the serum was separated. Samples were
transferred, at 0 – 4°C in a light-protected box, to the main laboratory
at the King Edward Memorial Hospital in Pune. EDTA samples for
red cell folate assay were diluted (1:19 by volume) with 10 g ascorbic
acid/L solution and incubated for 90 min at room temperature, before
being frozen at 280°C. An equal volume of 100 g metaphosphoric
acid/L was added to 0.5-mL serum aliquots for vitamin C assay, before
being frozen at 280°C. Samples were transferred to the United
Kingdom on dry ice. Red cell folate and serum ferritin concentrations
were measured in the Hematology Laboratory, Southampton General
Hospital (Southampton, U.K.) with radioimmunoassays (Becton
Dickinson U.K., Oxford, U.K.). Serum vitamin C concentrations
were measured at the Medical Research Council Human Nutrition
Research Center (Cambridge, U.K.) using an ascorbate oxidase–
orthophenylene diamine assay on a Roche Cobas Bio Centrifugal
analyzer (Hoffman-LaRoche, Basel, Switzerland) with a fluorescence
attachment (Vuilleumier and Keck 1989).
Physical workload assessment
Downloaded from jn.nutrition.org by guest on August 28, 2015
high level of physical activity (Piers et al. 1995). The majority
of previous studies in India have examined maternal diets in
terms of quantity (macronutrients) using 24-h recall method
but rarely assessed quality (micronutrients). Food frequency
questionnaires (FFQ) that are likely to offer estimates of habitual intake have rarely been used in studies of pregnant
women.
The assessment of maternal nutritional status requires the
measurement of body composition (before and during pregnancy), determination of energy intake and workload, measurement of patterns of food intake, consumption of macronutrients and micronutrients and biochemical measurements
of micronutrient status. In the Pune Maternal Nutrition Study,
we set out to relate the nutritional status before and during
pregnancy of women living in rural Maharashtra, India, to the
birth weight and other measurements of their babies. We
reported earlier (Fall et al. 1999) that the size at birth is
strongly predicted by maternal prepregnancy weight and
weight gain in pregnancy. Maternal height, head circumference and prepregnancy fat mass independently predicted the
birth weight of the baby. The present report describes our
findings in relation to maternal macronutrient intakes, intakes
of micronutrient-rich foods and biochemical micronutrient
status. For biochemical micronutrient status, we focused on
folate, iron and vitamin C. Folate and iron have traditionally
been considered important micronutrients for fetal growth,
and vitamin C is crucial for iron absorption.
The women’s typical daily physical activity was recorded at 18 and
28 wk gestation using simple numeric measures in a specially designed
activity questionnaire, which included farming and domestic activities. For example, domestic activities, such as cooking and washing
clothes/utensils, were recorded in terms of the number of people
catered for, whereas fetching water was recorded in terms of the
number of trips and number of containers carried. Using published
data on the energy cost of various activities (Bleiberg et al. 1981 and
1980, Lawrence et al. 1985), a weighted total daily score was derived.
This score reflected as a base unit, an activity level of 1 kcal (4.184
kJ)/min for a 30-min slot of time. The questionnaire was validated in
41 women using a 1-d minute-to-minute observer maintained records.
Activity scores obtained by questionnaire were significantly correlated (P , 0.05) with actual time spent in domestic (r 5 0.34) and
farming (r 5 0.56) activities. The total scores were used to rank
women into tertiles of “low,” “medium” and “high” physical activity.
Neonatal anthropometry
Babies were measured by one of five trained fieldworkers within
72 h of birth. Birth weight was measured to the nearest 50 g using a
Salter spring balance (Salter Abbey, Suffolk, U.K.); crown-heel
length was measured to the nearest 0.1 cm using a portable Pedobaby
Babymeter (ETS J.M.B., Brussels, Belgium). Triceps and subscapular
skinfold thicknesses were measured to the nearest 0.2 mm, on the left
MATERNAL DIET AND BIRTH SIZE IN RURAL INDIA
1219
weight of ,38 kg, and 9% were shorter than 145 cm, considered high risk for low birth weight (Gopalan 1989). Of the
women, 31.3% had a body mass index (BMI) of ,17 kg/m2,
indicating severe chronic energy deficiency (World Health
Organization 1995). Weight gain during pregnancy was 2.1
6 2.8 kg up to 18 wk and 5.5 6 2.9 kg up to 28 wk. All
measurements except maternal MUAC showed a significant
increase up to 28 wk’ gestation.
Statistical methods
Babies
Differences between group means were tested using t tests. Multiple regression analysis was used to examine trends in birth size
according to maternal dietary intakes and biochemical data and to
assess the relative contributions of other factors to the variability in
birth measurements. In regressions, birth measurements, maternal
measurements, energy and macronutrient intakes and erythrocyte
folate, vitamin C and ferritin concentrations were analyzed as continuous variables. Intakes of specific foods based on the FFQ and
socioeconomic and activity scores were analyzed as grouped variables.
However, when using the regression analysis, we weighted these
groupings to reflect as closely as possible the frequency of consumption per week. All analyses were adjusted for the baby’s sex, gestational age at delivery and maternal parity. Maternal and neonatal
skinfold measurements were skewed and required log-transformation
to satisfy assumptions of normality. Analysis was carried out using
SPSS/PC1, Version 5.0. Values unless otherwise stated are means
6 SD.
The full-term birth weight was 2665 g (Table 1), and 28%
of babies were of low birth weight (,2500 g). Even among
full-term babies, birth weight increased with gestational age (r
5 0.36). Birth weight, length and head circumference were
greater in boys than in girls (P , 0.01). All measurements
except length, head circumference and MUAC were smaller
in babies born to primiparous than in babies born to multiparous mothers (P , 0.05). In our analysis of birth size in
relation to nutritional data, we therefore adjusted for gestational age at delivery, baby’s sex and maternal parity.
RESULTS
Of the 797 women in the study, 12 had spontaneous abortions, 14 had late terminations and 1 died of pregnancyinduced hypertension. Seven hundred seventy infants were
delivered, of whom 8 were stillborn, 9 had major anomalies
detected at birth and 51 did not have birth measurements
within 72 h. Thus, of 702 of normal live births, our analysis
relates to 633 full-term infants.
Mothers
The mean age of the mothers was 21.4 y, and 31.6% were
primiparous. They were short, light and thin (Table 1).
Twenty-three percent of the women had a prepregnancy body
Downloaded from jn.nutrition.org by guest on August 28, 2015
side of the body, using Harpenden skinfold calipers (CMS Instruments, London, U.K.). Occipitofrontal head circumference and
MUAC were measured to the nearest 0.1 cm using Fiberglas tapes
(CMS Instruments, London, U.K.). Abdominal circumference was
measured at the level of the umbilicus in expiration. Placental weight
was recorded to the nearest 5 g using Ishida scales after trimming of
the umbilical cord and membranes. Interobserver and intraobserver
variation studies were conducted every 3 mo to ensure quality of these
measurements.
Dietary intakes
Macronutrients (24-h recall). Maternal energy and protein intakes at 18 and 28 wk were energy of 7.4 6 2.1 and 7.0
6 2.0 MJ and protein of 45.4 6 14.1 and 43.5 6 13.5 g,
respectively (Table 2). These values are low compared with
Recommended Daily Allowances for Indian pregnant women
given by the Indian Council of Medical Research (1987).
Carbohydrates were the main energy source (72%), whereas
10 and 18% of energy was derived from protein and fat,
respectively. Most protein was derived from cereals and pulses.
Only 38% of women consumed animal protein, which contributed only 15% to the daily protein intake. Activity scores
at 18 wk gestation were high (82.3 6 21.0), especially among
women from farming families, and remained so at 28 wk
gestation (76.6 6 23.2).
The birth weight of babies was not related to maternal
energy intakes, proportion of energy from animal products or
physical activity at 18 and 28 wk gestation. Because energy
intake and physical activity were interrelated (r 5 0.24, P
TABLE 1
Anthropometric measurements of the rural mothers before pregnancy and at 18 and 28 wk gestation
and of their full-term babies1
Maternal anthropometry
Parameter
Weight, kg
Height, cm
BMI,3 kg/m2
Head circumference, cm
MUAC, cm
Skinfold, mm
Subscapular
Triceps
Biceps
Suprailiac
Placental weight, g
Prepregnancy
(n 5 633)
18 wk gestation
(n 5 633)
28 wk gestation
(n 5 594)
41.7 6 5.1
151.9 6 5.1
18.1 6 1.9
52.3 6 1.5
22.5 6 1.8
43.8 6 5.0
—
18.9 6 1.8
—
22.3 6 1.7
47.3 6 5.2
—
20.5 6 1.7
—
22.7 6 1.7
10.9 6 4.0
8.9 6 3.5
4.3 6 1.8
10.0 6 5.2
—
12.4 6 4.1
9.2 6 3.3
4.3 6 1.7
13.2 6 5.8
—
13.6 6 4.4
9.8 6 3.5
4.6 6 1.8
15.8 6 6.6
—
1 Values are means 6 SD.
2 Ponderal index (kg/m3).
3 BMI, body mass index; MUAC, mid-upper arm circumference.
Neonatal
anthropometry
(n 5 633)
2.665 6
47.8 6
2.5 6
33.1 6
9.7 6
4.2
4.2
360.0
0.358
2.0
0.52
1.2
0.9
6 0.9
6 0.9
—
—
6 76.4
RAO ET AL.
1220
TABLE 2
Daily nutrient intake (modified 24-h recall) and physical
activity scores of rural mothers at 18 and 28 wk gestation1
18 wk gestation
(n 5 627)2
28 wk gestation
(n 5 609)2
7.40 6 2.1
45.4 6 14.1
34.9 6 14.8
7.0 6 4.7
72.1 6 5.1
10.3 6 1.0
17.5 6 4.8
7.00 6 2.0*
43.5 6 13.5*
32.4 6 14.0*
6.7 6 4.5
72.3 6 5.0
10.4 6 1.1
17.2 6 4.6
82.3 6 21.0
43.6 6 14.7
76.6 6 23.2*
43.5 6 14.6
Nutrient intakes
Energy, MJ/d
Protein, g/d
Fat, g/d
Animal protein,3 g/d
Carbohydrate, % energy
Protein, % energy
Fat, % energy
Daily activity scores4
Farming women
Nonfarming women
1 Values are means 6 SD. * Different from 18 wk gestation, P , 0.05.
2 Data were not available for 6 women at 18 wk and 24 women at 28
, 0.01 and 0.14, P , 0.01 at 18 and 28 wk gestation,
respectively), we examined the association of energy intakes
with birth weight after taking maternal size (prepregnancy
TABLE 3
Relationships between frequency of rural mothers’ intakes of green leafy vegetables and fruits at 28 wk gestation and of milk at
18 wk gestation and neonatal anthropometry1
Neonatal measurement
Food group
Frequency
n
Birth
weight
Birth
length
Head
circumference
g
Green leafy
vegetables,
wk 28
P1
P2
Fruits, wk 28
P1
P2
Milk products,
wk 18
P1
P2
MUAC2
Abdominal
circumference
Triceps
skinfold
cm
Subscapular
skinfold
mm
Placental
weight
g
Never
,13/wk
.13/wk
$Alternate
days
60
175
225
2571 6 356
2601 6 341
2675 6 363
47.0 6 2.0
47.5 6 1.9
48.0 6 2.0
32.6 6 1.2
32.9 6 1.2
33.2 6 1.2
9.6 6 1.0
9.6 6 0.8
9.7 6 0.9
28.2 6 1.8
28.2 6 2.0
28.6 6 1.9
3.9 6 1.4
4.0 6 1.2
4.1 6 1.2
3.9 6 1.2
4.1 6 1.2
4.0 6 1.2
347 6 69
354 6 66
358 6 82
149
,13/wk
.13/wk
$13/d
44
363
202
Never
,13/wk
.13/wk
$Alternate
days
95
134
116
2742 6 350
,0.001
,0.005
2598 6 340
2633 6 355
2721 6 357
,0.01
0.13
2643 6 369
2618 6 356
2639 6 344
47.9 6 1.9
,0.01
,0.05
47.5 6 1.7
47.5 6 2.0
48.1 6 1.9
,0.01
0.23
47.5 6 2.0
47.6 6 2.0
47.6 6 2.0
33.3 6 1.2
,0.001
,0.005
32.7 6 1.1
32.9 6 1.2
33.4 6 1.2
,0.001
,0.01
32.9 6 1.2
33.0 6 1.2
33.0 6 1.1
9.9 6 0.9
,0.05
,0.05
9.7 6 0.8
9.6 6 0.9
9.8 6 0.8
0.09
0.80
9.6 6 1.0
9.7 6 0.9
9.5 6 0.8
29.1 6 1.7
,0.001
,0.005
28.6 6 2.0
28.5 6 1.9
28.8 6 1.9
0.15
0.45
28.5 6 2.1
28.6 6 1.7
28.5 6 1.9
4.4 6 1.2
,0.001
,0.001
4.1 6 1.2
4.1 6 1.2
4.1 6 1.2
0.44
0.38
4.2 6 1.2
4.1 6 1.2
4.1 6 1.2
4.3 6 1.2
,0.05
,0.05
4.2 6 1.2
4.1 6 1.2
4.2 6 1.2
0.67
0.99
4.1 6 1.2
4.1 6 1.2
4.1 6 1.2
371 6 81
,0.05
0.41
352 6 76
353 6 75
370 6 79
,0.05
0.07
354 6 78
348 6 79
352 6 71
2704 6 361
,0.05
0.14
48.0 6 2.0
,0.05
0.13
33.2 6 1.3
,0.01
,0.01
9.8 6 0.9
,0.05
0.11
28.8 6 2.0
0.15
0.52
4.1 6 1.2
0.90
0.48
4.1 6 1.2
0.41
0.46
371 6 77
,0.01
,0.01
281
Downloaded from jn.nutrition.org by guest on August 28, 2015
wk gestation.
3 This relates to the 38% of women who ate animal proteins (meat,
fish, eggs or milk products, excluding milk in tea/coffee) on the 24-h
recall day.
4 Number of farming women at 18 wk gestation was 481 and at 28
wk gestation 405, non-farming women at 18 wk gestation 146 and at 28
wk 204.
weight, height and BMI) and maternal physical activity into
account. There was no significant relationship. Similarly, protein and carbohydrate intakes (either absolute or as a percentage of total energy) were unrelated to birth measurements. In
contrast, higher fat intake at 18 wk gestation was associated
with greater neonatal length (P , 0.001) and triceps skinfold
thickness (P , 0.01). After adjustment for maternal size and
social status, fat intake at 28 wk gestation was associated only
with birth length (P , 0.05).
Food groups (FFQ). Of the 17 food groups assessed using
the FFQ, significant relationships with birth size were found
with GLV, fruits and milk products.
GLV. The GLV eaten frequently (more than once a week)
in this community were fenugreek leaves (57% of women),
spinach (33%), coriander (16%) and colocasia (15%). The
frequency of consumption of GLV at 28 wk was strongly
related to all birth measurements (Table 3). These relationships remained significant after adjustment for prepregnancy
weight (or height and BMI), energy intakes, physical activity
score, weight gain during pregnancy and socioeconomic status
(Table 4). An increase in frequency of consumption from one
group to the next higher group was associated with an increase
in birth weight of 19 g [95% confidence interval (CI), 8 –30]
after adjustments for all of these factors. The trend with birth
weight was stronger (value of partial regression coefficient
increased to 30 g; 95% CI, 13– 47) among the lightest mothers, those with a prepregnancy weight below the lowest tertile
(40 kg). The odds ratio for delivering a low birth weight baby
was 0.43 (95% CI, 20.12 to 0.99) in mothers who ate GLV at
least every other day compared with 1.0 in mothers who never
ate them.
1 Values are means 6 SD. P1 values after adjustment for sex, parity and gestational age at delivery. P2 values after additional adjustment for
prepregnancy weight, energy intake, activity, social class, weight gain up to 28 wk and relevant micronutrients and macronutrients (for green leafy
vegetables, erythrocyte folate concentration; for fruits, serum vitamin C concentration; for milk products, fat intake).
2 MUAC, mid-upper arm circumference.
MATERNAL DIET AND BIRTH SIZE IN RURAL INDIA
1221
TABLE 4
Multiple regression analysis of the relationship of the frequency of maternal intakes of green leafy vegetables, fruits and milk
products with birth weight among rural Indian women1
Green leafy vegetable
intake at 28 wk gestation
Dependent
variable
Birth weight, g
Independent parameters
Sex, parity, gestation at birth
Sex, parity and gestation at
birth plus prepregnancy
weight,2 energy intake,
activity, social status and
weight gain up to 28 wk and
micronutrients and
macronutrients3
R2
b
P
22.1
(1.8)
32.6
(1.8)
19.1
,0.001
19.4
,0.001
Fruit intake
at 28 wk gestation
R2
21.4
(1.0)
29.8
(0.34)
Milk product intake
at 18 wk gestation
b
P
R2
b
P
7.4
,0.01
6.9
0.08
4.3
0.12
20.5
(0.7)
29.4
(0.4)
4.8
0.06
Fruits. Pregnant women had relatively high intakes of
“vitamin C–rich” fruits, which were freely available from trees
growing in the fields. These fruits included zizapus (eaten more
than once a week by 58% of women), raw tamarind (48%) and
guava (40%). The frequency of consumption of fruits at 28 wk
gestation was related to birth weight, birth length, head circumference and placental weight but not to measures of neonatal fat, MUAC or abdominal circumference (Table 3).
These relationships remained significant after adjustment for
prepregnancy weight (or height and BMI), energy intake,
physical activity score and socioeconomic score but not after
adjustment for weight gain (Table 4). Similar to GLV, relationships were stronger among lighter mothers. An increase in
the frequency of fruit consumption from one group to the next
higher group was associated with an increase in birth weight of
4 g (95% CI, 21 to 10) in the sample as a whole and 15 g
(95% CI, 6 –24) in women with a prepregnancy weight of ,40
kg (Table 4).
Milk products. Milk was consumed mostly by women
from families who owned milk-producing animals. It was consumed either with roti or rice or was drunk but rarely was
consumed in the form of other milk products. Milk consumption was strongly associated with socioeconomic score (P
, 0.001). The frequency of milk consumption at 18 wk
gestation was related to birth weight, birth length, MUAC,
head circumference and placental weight but not to measures
of neonatal fat or abdominal circumference (Table 3). In
contrast to GLV and fruits, these relationships were stronger at
18 wk’ than at 28 wk gestation. They were similar at all levels
of prepregnancy maternal weight and remained significant
after adjustment for prepregnancy weight (or height and BMI),
energy intakes, physical activity score, socioeconomic status
and weight gain (Table 4).
In all of these regression analyses, the major contribution
was from main confounding variables (gestation, sex and parity: ;20%). The contributions of dietary variables varied from
2 to 3% but were significant.
Biochemical indices of maternal nutrition
Downloaded from jn.nutrition.org by guest on August 28, 2015
1 Dietary variables were grouped (as in Table 3) and were weighted to reflect as closely as possible the consumption per week. Therefore, the b
coefficient represents the increase in birth weight associated with increased consumption of that food group by one time per week. Values in
parentheses represent the contribution of dietary variables to R2.
2 Replacement of prepregnancy weight with height and body mass index did not change the relationship (R2, b values and significance).
3 Indicates further adjustment for other variables, including micronutrients and macronutrients: for green leafy vegetables, erythrocyte folate
concentration; for fruit, serum vitamin C concentration; for milk products, fat intake. The exclusion of gestation from this regression reduced R2 values
for the three food groups to 22.0, 17.8 and 16.9%, respectively, whereas the contribution of dietary variables increased to 2.05, 0.5 and 0.4%,
respectively.
Concentrations of erythrocyte folate, serum ferritin and
serum vitamin C [median (interquartile range)] were 868
nmol/L (687–1097), 13 mg/L (8 –23) and 10 mmol/L (2–31) at
18 wk gestation and 968 nmol/L (741–1273), 10 mg/L (7–20)
and 6 mmol/L (1–22) at 28 wk gestation. All three micronutrients were related to birth size (Table 5). The strongest and
most consistent relationship was with 28-wk erythrocyte folate
concentration, which was positively related to birth weight,
birth length, head circumference, MUAC, abdominal circumference and placental weight but not to skinfold thickness.
Higher serum vitamin C concentration at 28 wk gestation was
associated with higher birth length, MUAC and abdominal
circumference (Table 5), and higher concentration at 18 wk
gestation was associated with higher MUAC (P , 0.05) and
triceps skinfold thickness (P , 0.05). In contrast, ferritin
concentration at 28 wk gestation was inversely related to birth
length, MUAC and abdominal circumference (Table 5). All
of these relationships remained significant after adjustment for
prepregnancy weight (or height and BMI), energy intakes,
physical activity, weight gain and socioeconomic status.
GLV are a rich source of folate. Higher intakes at 28 wk
gestation were associated with higher erythrocyte folate concentration (1099 nmol/L in women who ate GLV at least once
every other day compared with 949 nmol/L in those who never
ate them, P , 0.05). The relationship between intake of GLV
with birth weight remained significant after adjustment for
erythrocyte folate concentration (Table 4). Similar analysis
revealed that this relationship was also strong for all other
neonatal measurements. GLV are also a rich source of iron.
GLV intakes were not, however, related to serum ferritin
concentration. Fruits consumed by rural mothers were rich in
vitamin C, and higher fruit intakes were associated with
higher serum vitamin C concentration (19 mmol/L in women
who ate fruit at least once daily compared with 11 mmol/L in
those who ate fruit less than once a week; P , 0.05). The
relationship of fruit intake to birth weight was not significant
(P 5 0.13) after adjustment for serum vitamin C concentra-
RAO ET AL.
1222
TABLE 5
Relationship’s between rural mothers’ erythrocyte folate, serum ferritin and serum vitamin C concentrations at
28 wk gestation and neonatal anthropometry1
Neonatal measurement
Blood
nutrient
Concentration
n
Birth
weight
Birth
length
Head
circumference
g
Erythrocyte
folate,
nmol/L
P1
P2
Serum ferritin,
mg/L
P1
P2
Abdominal
circumference
Triceps
skinfold
cm
Subscapular
skinfold
mm
Placental
weight
g
,816
171
2616 6 360
47.5 6 1.9
33.0 6 1.3
9.5 6 0.9
28.4 6 2.0
4.1 6 1.2
4.2 6 1.2
347 6 78
816–1147
171
2637 6 369
47.7 6 2.3
32.9 6 1.2
9.7 6 0.8
28.6 6 1.7
4.1 6 1.2
4.1 6 1.2
356 6 66
$1147
172
,8
8–16
$16
162
196
185
,4
4–19
$19
254
169
146
2727 6 347
,0.001
,0.001
2695 6 362
2657 6 350
2649 6 378
0.20
0.18
2647 6 343
2679 6 353
2688 6 396
0.23
0.29
48.1 6 1.8
,0.05
0.08
47.7 6 2.0
47.8 6 2.0
47.7 6 2.1
,0.05
,0.05
47.6 6 2.0
47.8 6 2.0
47.9 6 2.0
,0.05
0.07
33.3 6 1.2
,0.05
0.12
33.1 6 1.3
32.9 6 1.2
33.2 6 1.3
0.85
0.86
33.0 6 1.2
33.1 6 1.2
33.1 6 1.3
0.70
0.70
9.8 6 0.9
,0.005
,0.01
9.8 6 0.8
9.7 6 0.8
9.6 6 1.0
,0.01
,0.01
9.7 6 0.8
9.6 6 0.9
9.8 6 1.0
,0.01
,0.05
28.9 6 1.9
,0.005
,0.01
28.9 6 1.7
28.6 6 1.8
28.5 6 2.1
,0.05
,0.05
28.5 6 1.9
28.7 6 1.7
29.0 6 2.1
,0.01
,0.05
4.2 6 1.2
0.19
0.26
4.2 6 1.2
4.2 6 1.2
4.1 6 1.2
0.18
0.28
4.1 6 1.2
4.2 6 1.2
4.2 6 1.2
0.07
0.15
4.1 6 1.2
0.64
0.79
4.2 6 1.2
4.1 6 1.2
4.1 6 1.2
0.22
0.25
4.1 6 1.2
4.1 6 1.2
4.2 6 1.2
0.59
0.75
374 6 83
,0.001
,0.001
361 6 76
364 6 65
355 6 90
0.21
0.15
356 6 75
360 6 79
367 6 78
0.92
0.84
Downloaded from jn.nutrition.org by guest on August 28, 2015
P1
P2
Serum vitamin
C, mmol/L
MUAC
1 Values are means 6 SD. P1 values after adjustment for sex, parity and gestational age at delivery. P2 values after additional adjustment for
prepregnancy weight, energy intake, activity, social class and weight gain up to 28 wk gestation.
tion (Table 4) but remained significant for head circumference. Similarly, milk was a major contributor (29%) to total
fat intake, and after adjustment for fat intakes, the relationship
of milk consumption with birth weight (Table 4) was not
significant (P 5 0.10) but remained significant for neonatal
length (P , 0.005) and triceps skinfold thickness (P , 0.01).
DISCUSSION
We studied the size of rural Indian newborn babies in
relation to their mothers’ diets and circulating micronutrient
concentrations in pregnancy. The strengths of our study were
that it was community based, wherein prepregnancy maternal
anthropometry and accurate gestational age were recorded.
We also developed community-specific methods for estimating
dietary intakes objectively, and we report data on the consumption of various food groups as well as nutrient intakes.
Rural mothers were thin and short, indicating that many
were chronically energy deficient before conception. Although
their mean weights and heights were similar to those reported
from other rural areas of India (Vijayalaxmi et al. 1988), they
were significantly less than those of urban affluent Indian
(Devi et al. 1989, Gupta and Sharma 1980, Piers et al. 1995)
and Western (Godfrey et al. 1996) mothers. The neonatal size
was similar to that reported in other Indian populations (Mohan et al. 1990) but markedly smaller than that of Western
babies (Godfrey et al. 1996).
Maternal intakes of energy and protein were low, ;70 –
75% of recommended intakes (ICMR 1987) at both time
points, and showed no significant relationships with neonatal
size. For energy intakes, the lack of any relationship with birth
size was true for the whole study group, within subgroups of
maternal prepregnancy weight and after taking physical activity into account. It was also true when women with extremely
low intakes (,1.2 basal metabolic rate, n 5 150) were excluded. These important negative findings are consistent with
the slight effects on birth size of energy and protein supplementation trials in pregnancy (Kramer 1993).
Among the macronutrients, only fat intake at 18 wk gestation showed an association with birth size. Fat intake has
been shown to correlate with birth weight (Doyle et al. 1982),
but there are few data for fat reported as an entity separate
from energy. Recent studies suggest that specific fatty acids are
important for fetal growth (Crawford et al. 1989), which
brings into question whether fat is a macronutrient or micronutrient.
Birth size was strongly related to intakes of GLV and fruits
at 28 wk gestation and of milk at 18 wk gestation. These three
food groups are particularly rich in micronutrients. Our observations therefore suggest the importance of specific micronutrients, or their combinations, for fetal growth. For example,
GLV are a rich source of folate, iron, provitamin A carotenoids and antioxidants. Increased frequency of the consumption of GLV was associated with an increase in all neonatal
anthropometry, and the relationship with birth size remained
significant even after correction for red cell folate concentration in blood, suggesting that nutrients other than folate
contribute to the relationship. Similarly, fruits are rich in
vitamin C and other antioxidants, whereas milk provides high
quality proteins, fat, calcium, riboflavin and vitamins A and D.
It was interesting to note that a greater consumption of fruits
or milk was not associated with increased measures of neonatal
fat or abdominal circumference, as occurred for the consumption of GLV. Furthermore, the relationship with fruit consumption when corrected for circulating vitamin C concentration in blood did not remain significant for group as a whole
but was significant only for thin mothers. Similarly, the relationship of milk consumption after adjustment for fat intake
did not remain significant for birth weight but was significant
for length and triceps skinfold thickness. This suggests important roles of different micronutrients in improving fetal
growth.
MATERNAL DIET AND BIRTH SIZE IN RURAL INDIA
Thus, food-based interventions may be more beneficial. There
are limited data from controlled trials on the effects of micronutrients on fetal growth. Most have shown a small or no
effect (Mathews 1996, Onis et al. 1998). The long-term implications of our findings that specific maternal food intakes
are related to different components of neonatal phenotype are
unknown at this stage and could be best understood by following these babies to determine infant mortality rates, childhood growth rates and long-term health. Further research, in
animals and humans, is needed to identify the important
nutrients provided by these key food groups and their mode of
action. We also believe an intervention trial should be attempted to study the effects of increased availability of these
foods for pregnant women.
ACKNOWLEDGMENTS
We are grateful to the community and to the pregnant women and
their families for their cooperation. We would like to thank David
Collis and the staff of the Special Hematology Laboratory
(Southampton General Hospital, Southampton, U.K.) for the ferritin
and folate assays and Chris Bates, Glynn Harvey and Jonathan
Perkins (Medical Research Council Resource Center for Human
Nutrition Research, Cambridge, U.K.) for the vitamin C assays. We
also thank A. D. Agate (Director, Agharkar Research Institute),
V. N. Rao (Director, the King Edward Memorial Hospital Research
Center) and K. J. Coyaji (Director, Department of Obstetrics and
Gynecology, King Edward Memorial Hospital) for providing the
facilities for this collaborative research. We acknowledge the contributions made to the study by Arun Kinare, Monesh Shah, Asit
Natekar, Manoj Chinchwadkar, Binu John, Anuja Bisht, Mahananda
Bhavikatti, Poonam Gupta, Charu Joglekar, Parveen Bharucha and
Vanessa Cox.
LITERATURE CITED
Downloaded from jn.nutrition.org by guest on August 28, 2015
One of the causal pathways for the effect of micronutrients
could be an increase in the gestational period. The exclusion
of gestation from regression analyses in Table 4 showed marginal increase in the contribution of respective dietary variables in R2 and keeps the relationship significant. However, its
inclusion explains up to 15% of the variability in birth weight
and substantially increases the overall R2. This suggests that
the effect of micronutrient intakes on fetal growth is in part
mediated through the lengthening of the gestation.
Birth measurements were related to intakes of GLV and
fruit at 28 wk, whereas they were related to fat and milk
intakes at 18 wk. This may reflect different nutrient requirements for fetal growth at these times due to the development
of different tissues at various stages of gestation (Dugdale and
Payne 1975, Tanner 1989). The relationships of GLV and fruit
intake to birth size were strongest in lighter and thinner
women. We did not detect any significant difference in other
factors (parity, macronutrient intake, blood pressure and glycemic status) associated with fetal growth in these women
compared with the remainder of the group. It is likely that
micronutrients may be the most important limiting nutrients
in undernourished women.
We found inverse relationships between maternal serum
ferritin concentration at 28 wk gestation and neonatal size.
This somewhat paradoxical finding has been reported in other
populations (Goldenberg et al. 1996) and might be explained
by hemodilution effects due to plasma volume expansion,
which is associated with increased fetal growth (Rosso et al.
1992). Because ferritin represents a stored form of iron, an
alternative explanation is that a lower ferritin concentration
in the mother signifies the successful mobilization of iron,
making it available for fetal growth. It is interesting, in this
respect, that the inverse relationships of serum ferritin concentration were strongest with neonatal MUAC (representing
muscle) and abdominal circumference (representing viscera),
tissues with a high iron content.
To our knowledge, this study is the first to show an association between maternal intakes of GLV, fruits and milk and
size at birth . Furthermore, the significant relationship between
biomarkers (erythrocyte folate and serum vitamin C) and the
frequency of consumption of GLV and fruits, respectively,
provides a measure of confidence in our FFQ assessment.
Although we cannot assume cause-and-effect relationships in
any of the associations we have described, our data suggest that
improved maternal intakes of milk in early gestation and of
GLV and fruit in late gestation could lead to improved fetal
growth. There may be concern in attributing significance to
these foods because we had conducted multiple analyses of 17
food groups. We did, however, start with the a priori hypothesis that micronutrient-rich foods may be important for fetal
growth. If the P-value was corrected for these 17 food groups,
making P 5 0.003 the cutoff for statistical significance, the
relationship between birth size and GLV remains significant.
There is controversy as to whether food or pharmacology is
the best means of providing micronutrients (West 1996).
There is some evidence that supplementation with folate in
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1970, Ek 1982, Goldenberg et al. 1992, Iyengar and Rajalakshmi 1975). However, an evaluation of India’s long-standing
anemia prophylaxis program, with routine iron and folate
supplementation to women in the third trimester of pregnancy
for the past two decades, demonstrates no significant impact
on birth weight (ICMR 1989). It may be that the micronutrient-rich foods discussed here provide a more effective combination of nutrients than do conventional supplements that
contain only one or two micronutrients or macronutrients.
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