3–7 September 2006, London, UK an increase of 190.8% (p < 0.05). Vmean of the renal artery increased significantly between the 20–24 week and the 37th–40th week (9.56 cm/s vs. 20.15 cm/s, p < 0.05). Area of the renal artery increased significantly between the 20–24 weeks and the 37–40 weeks (6.78 mm2 vs. 10.12 mm2, p < 0.05). No significant increase in RI or PI was observed. At the 20–24 weeks of gestation, renal artery waveforms consisted of 43.5% type I (only systolic waves) and 56.5% (systolic waves and some diastolic waves). Type III (systolic waves and persistent diastolic waves) was not recognized. At 25–28 weeks, they consisted 28.3% type I, 63.0% type II, and 8.7% type III. At the 29–32 weeks, type I decreased, and frequency of type II was 78.2%. At the 37–40 weeks, 76.1% type III, type II decreased to 23.9%, and type I was not recognized. Conclusions: Vmax was found to be the most effective index because it was easy to measure and the significant change of gestation progresses. The renal blood flow waveforms changed as advanced gestation in normal growth fetuses. P07.17 Transverse cerebral sinus Doppler velocimetry in the prediction of fetal acidemia: which is the best parameter? Poster abstracts Maternidade-Escola Assis Chateaubriand) who were submitted to TCS Dopplervelocimetry in the last 24 hours before delivery. All pregnancies were singleton, over 26 weeks of age and without structural or chromosome anomalies. Metabolic or mixed acidemia at birth were considered pathological. A ROC curve was calculated for the PIV and (S-A)/S of the TCS (independent variable) and acidemia (dependent variable). A cut-off value was established and sensibility, specificity, positive and negative predictive values and positive and negative likelihood ratios were calculated. Results: The PIV of the TCS was a good predictor of acidemia (ROC curve area 0.698, p = 0.009) and (S-A)/S ratio is also a good predictor of acidemia (ROC curve area 0.654, p = 0.009). The cut off value was PIV = 0.85, sensibility 66.7%, specificity 77.1% and accuracy 73.9%. The cut off value was (S-A)/S = 0.70, sensibility 52.4%, specificity 79.2% and accuracy 71.0%. Conclusions: In this high-risk population the pulsatility index for veins and (S-A)/S ratio of the transverse cerebral sinus was good predictor of acidemia at birth. M. M. Barbosa1 , F. H. C. Carvalho2 , E. Cordioli1 , L. C. S. Bussamra1 , R. M. Santana1 , A. F. Moron1 Universidade Federal de São Paulo, Brazil, 2 Maternidade Escola Assis Chateaubriand, Brazil 1 Objectives: To evaluate the prediction of fetal acidemia using Transverse cerebral sinus (TCS) Dopplervelocimetry and to determine the best parameter and cut-off values for this prediction in pregnancies complicated with placental insufficiency. Patients and Methods: This was a prospective cross-sectional study involving sixty-nine patients with placental insufficiency managed in two Brazilian hospitals (Hospital São Paulo and Maternidade-Escola Assis Chateaubriand) who were submitted to TCS Dopplervelocimetry in the last 24 hours before delivery. All pregnancies were singleton, over 26 weeks of age and without structural or chromosome anomalies. Metabolic or mixed acidemia at birth were considered pathological. A ROC curve was calculated for each TCS parameter (independent variable) and acidemia (dependent variable). A cut-off value was established and sensibility, specificity, positive and negative predictive values and positive and negative likelihood ratios were calculated. The MacNemar test was used to compare the parameters. Results: The TCS S, D and A peak velocities were not good predictors of acidemia at birth. Pulsatility Index for Veins (PIV) was a good predictor of acidemia (ROC curve area 0.698, p = 0.009), as well as (S-A)/S ratios (ROC curve area 0.654, p = 0.009). The cut off values were PIV = 0.85 and (S-A)/S = 0.70. Conclusions: In this high-risk population angle-independent TCS Doppler indexes were good predictors of birth acidemia. PIV, (S-A)/S ratios were statistically equivalent in this prediction. P07.18 Transverse cerebral sinus Doppler velocimetry in the prediction of birth acidemia M. M. Barbosa1 , F. H. C. Carvalho2 , E. Cordioli1 , L. C. S. Bussamra1 , R. M. Santana1 , A. F. Moron1 1 Universidade Federal de São Paulo, Brazil, 2 Maternidade Escola Assis Chateaubriand, Brazil Objectives: Evaluate the prediction of acidemia at birth using the pulsatility index for veins (PIV) of the transverse cerebral sinus (TCS) and to determine the cut-off value for this prediction in pregnancies complicated with placental insufficiency. Patients and Methods: This was a prospective cross-sectional study involving sixty-nine patients with placental insufficiency managed in two Brazilian hospitals (Hospital São Paulo and Ultrasound in Obstetrics & Gynecology 2006; 28: 512–614 P07.19 A study to compare prenatal adaptations of viable small-for-gestational-age fetuses at less than 30 weeks’ gestation depending on presence or absence of pre-eclampsia E. Cosmi1 , J. Santolaya-Forgas2 , R. Uhlmann2 , C. Saccardi1 , A. Baschat3 , V. Berghella4 , G. Mari2 1 University of Padua School of Medicine, Italy, 2 Wayne State University, United States, 3 University of Maryland, United States, 4 Thomas Jefferson University, United States Objective: Our primary objective was to determine if pre-eclampsia would lead to distinct prenatal adaptations in viable SGA fetuses of less than 30 weeks gestational age. Our secondary objective was to determine if the perinatal mortality of SGA fetuses at these gestational ages could be affected by the presence or not of preeclampsia. Methods: With these purposes in mind we performed a case control study on 31 fetuses matched for gestational age, 7 controls, 13 SGA with pre-eclampsia, and 11 SGA without pre-eclampsia. All prenatal evaluations were performed between 24 and 30 weeks gestation. Estimated fetal weight, umbilical and middle cerebral arteries pulsatility indices (UA-PI; MCA-PI), presence of absent/reverse flow in the ductus venosus, gestational age at delivery, birth weight, and perinatal mortality rate were recorded and compared using chi-sq or ANOVA as appropriate (p < 0.05 was considered significant). Results: Table 1 summarizes results from prenatal studies and perinatal outcomes. Conclusion: Findings from these comprehensive prenatal studies suggest that SGA fetuses between 24 and 30 weeks gestation undergo different adaptations depending on presence or not of pre-eclampsia. SGA of preeclamptic mothers have: 1) Greater redistribution of blood flow as determined by higher UA-PI and lower MCA-PI; 2) Lesser rate of severe abnormalities at the ductus venosus; 3) More 573