Fetal growth restriction: First trimester abnormal analytes, second trimester uterine artery—complementary or redundant?

Abstract

<h3>Objectives</h3> To assess the utility of uterine artery Doppler study and the risk of fetal growth restriction (FGR) in the presence of abnormal serum analytes in the first trimester screening (FTS). <h3>Methods</h3> We conducted a retrospective cohort study of women who had a placental study following abnormal serum analytes in FTS. FTS included PAPP-A, PlGF, free β-hCG and AFP. Placental ultrasound was conducted during the second trimester and included the gestational age-adjusted mean uterine artery pulsatility index (UtA-PI). Outcomes of pregnancies with elevated UtA-PI (MoM >95% percentile) were compared with those of pregnancies with normal UtA-PI (≤95% percentile). ROC curve was calculated to assess the utility of uterine artery Doppler study in the prediction of FGR. <h3>Results</h3> 546 women were included. Of those, 52 (9.5%) had elevated UtA-PI. This group had higher mean pre-pregnancy BMI and higher rates of abnormal PAPP-A and ≥2 abnormal analytes. All other characteristics were similar between groups. Neonates of women with elevated UtA-PI had lower mean birth weight (BW), and higher rates of BW <3rd, 5th and 10th percentile. The area under the ROC curve for predicting FGR <3rd percentile was 0.690 for UtA-PI, 0.643 for PAPP-A, and 0.720 for their combination, with overlapping confidence intervals, indicating that the combination did not significantly improve the predictability of FGR <3rd percentile. Similar patterns emerged for FGR <5th and 10th percentile. <h3>Conclusions</h3> In women at high risk for FGR based on abnormal FTS analytes, elevated UtA-PI is associated with higher rates of FGR but does not improve the prediction of FGR.