Are first-trimester ultrasound features prior to 11 weeks' gestation and maternal factors able to predict maternal hypertensive disorders?

OBJECTIVES: Maternal hypertensive disorders (MHD) including pregnancy-induced hypertension (PIH) and pre-eclampsia (PET) are estimated to occur in 7-10% of pregnancies world-wide and have significant short- and long-term implications for both mother and fetus. This study aimed to determine (i) if conventional and novel early first trimester ultrasound measures are associated with MHD; and (ii) if these ultrasound measures plus maternal characteristics and biochemistry improve the prediction of this adverse pregnancy outcome. METHODS: This was a prospective cohort study including ultrasound measurements recorded at 5+1 to 11 weeks' gestation: mean sac diameter (MSD), yolk sac diameter, crown-rump length, fetal heart rate (FHR), trophoblast thickness, trophoblast volume (TV) and mean uterine artery pulsatility index. Maternal biochemistry considered in analysis included beta human chorionic gonadotropin, pregnancy - associated plasma protein A (PAPP-A), placental growth factor (PIGF) and maternal serum alpha fetoprotein. Regression models were fitted for each ultrasound parameter and multiples of the median (MoM) calculated. All measures were compared between cohorts that had a normotensive outcome or subsequently developed MHD. Logistic regression analysis was used to create a prediction model for MHD based on maternal characteristics, ultrasound measurements recorded at 5+1 to 11 weeks' gestation, and maternal biochemistry taken at 10-14 weeks. RESULTS: The maternal weight of women who developed hypertension was significantly greater compared to normotensive women (p<0.0001). Mean MoM values for TV (p = 0.006), PAPP-A (p=0.031) and PlGF (p = 0.044) were all significantly decreased in pregnancies with mothers who subsequently developed hypertension. The proposed logistic regression model includes maternal weight, height, TV, FHR and PIGF resulting in an area under the receiver operator curve 0.80 (95%CI 0.75-0.86). CONCLUSION: The combination of maternal weight and height, TV, FHR and PIGF appears of good predictive value for the development of MHD later in pregnancy. This article is protected by copyright. All rights reserved.