(734) Uterine Artery Doppler, Placental Volume, and the Risk for Hypertensive Disorders of Pregnancy

Objective: Hypertensive disorders of pregnancy (HDP) constitute a leading cause of maternal and perinatal morbidity and mortality worldwide. Early identification of pregnancies at risk for HDP could lead to improved risk stratification and surveillance to reduce morbidity and mortality. Our objective was to evaluate the risk for developing HDP by evaluating first trimester placental volume and uterine artery (UtA) Doppler velocimetry.

Study Design: Retrospective case-control study of 664 patients with singleton gestations who presented for aneuploidy screening between 10 3/7 and 13 6/7 weeks’ gestation. Each patient had three-dimensional placental volumes and bilateral UtA Doppler studies performed transabdominally with a Voluson E8 (GE Healthcare, Milwaukee, WI). UtA resistance index (RI) and notching were assessed. A placental quotient (PQ) was calculated by dividing the placental volume by the crown rump length. A UtA score was calculated by assigning one point for an RI >0.70 ( >75th percentile) and one point for reproducible diastolic notching. The UtA score was calculated for each artery with points combined for a total score between 0-4. Next, UtA scores were grouped into three groups: score of 0, score of 1-2, and score of 3-4. Logistic regression was used to investigate the associations of PQ and UtA score groups with HDP.

Results: PQ was not significantly associated with HDP (p = 0.12). The largest difference between UtA score groups occurred between groups 1-2 and 3-4 in predicting the development of preeclampsia (with and without severe features) (OR: 0.28, 95% CI: 0.12-0.66,p = 0.003). This relationship remained significant after adjusting for parity, body mass index, and chronic hypertension.

Conclusion: In this low-risk population, placental volume does not appear to be associated with HDP in the first trimester. A combination of increased RI and notching is associated with an increased risk of developing preeclampsia. Additional larger studies are warranted to confirm this finding in a low-risk patient population.