321. Is small placental biometry independent of increased uterine artery Doppler resistance for the prediction of fetal growth restriction

Introduction Fetal growth restriction (FGR) is associated with significant perinatal morbidity and mortality. Therefore, early prediction of FGR remains an important research question. 2-dimensional placental biometry offers an affordable and readily available adjunct to uterine artery (UtA) Doppler and fetal biometry measurement in the prediction of FGR. Objective To determine if there is an association between placental biometry and birthweight and explore its relationship with UtA Doppler. Methods This was a retrospective study of 820 pregnant women presenting to the high-risk research clinics at a tertiary centre. Women underwent a “placental screen” at 22–24 weeks’ gestation, during which UtA Dopplers, fetal and placental biometry were measured. FGR was defined as birthweight t -test. Results 74/820 pregnancies were complicated by FGR. Placental size was significantly smaller in FGR pregnancies and correlated with birthweight centile (p  Discussion Smaller placental biometry independently predicts FGR although there is a relationship with increased UtA PI. This suggests that an alternate pathological process causing reduced placental growth aside from reduced placental perfusion might be present in some cases of FGR. Research exploring the relationship between placental size and fetal and neonatal growth is required to investigate this further.