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211: Early fetal growth abnormalities and development of severe preeclampsia: the NICHD fetal growth studies

      Objective

      Preeclampsia is hypothesized to be associated with abnormal vascular development of the placenta resulting in fetal growth abnormalities. Our objective was to determine whether abnormal fetal growth in the first or second trimester was associated with the later onset of severe preeclampsia.

      Study Design

      In a secondary analysis of a multicenter longitudinal study of fetal growth, women had six serial sonographic exams across gestation. Pregnancies were classified as severe preeclampsia (severe-PE) and normotensive based on discharge diagnosis. Crown to rump length (CRL) measurements (mean ± SEM) for the severe-PE group were adjusted for gestational age between 8w0d and 13w6d and compared to the normotensive group using non-parametric tests. Estimated fetal weight (EFW), biparietal diameter (BPD), head circumference, abdominal circumference, and femur length (mean ± SEM) for the severe-PE group between 15-24 weeks’ gestation were also compared in a similar fashion. Receiver operating characteristic (ROC) curves were created whenever statistical difference in CRL and biometric parameters was noted between the groups.

      Results

      Of 2,436 pregnancies analyzed, 2402 (98.6%) were normotensive and 34 (1.4%) had severe-PE. There were no differences in CRL measurements between the groups (p=0.29). EFW between 15 and 20 weeks of gestation were significantly lower in women who subsequently developed severe-PE compared to normotensive women (Figure; p=0.01). Similar findings were noted for all individual biometries (all p < 0.05) between 15 and 20 weeks, except BPD (p=0.052). Area under ROC curve was 0.685 for predicting subsequent severe PE based on abnormal EFW at 15-20 weeks’ gestation. No fetal growth differences were identified between 20 and 24 weeks of gestation for the severe-PE group compared to normotensive patients.