De-novo abnormal uteroplacental circulation in third trimester: pregnancy outcome and pathological implications

Hypertensive disorders of pregnancy (HDP) are associated with impaired placentation, as evidenced by abnormal uterine artery (UtA) Doppler. In normal pregnancy, mean UtA pulsatility index (PI) shows a progressive decline with gestational age (GA). However, previous studies have reported that a proportion of pregnancies demonstrate worsening UtA Doppler in later pregnancy. The aim of this study was to investigate the incidence of HDP according to the change in mean UtA-PI between the second and third trimesters.

This was a retrospective cohort study of singleton pregnancies between March 1997 and March 2016 that underwent longitudinal UtA Doppler assessment in the second and third trimesters. All parameters were converted into centiles or multiples of the median (MoM), adjusting for GA. The study cohort was divided into two groups, according to change in mean UtA-PI between the second and third trimesters (those with a decrease or no change and those with an increase). HDP included women who developed pre-eclampsia and/or gestational hypertension. Logistic regression analysis was used to adjust for potential confounders.

The analysis included 5887 pregnancies. The incidence of HDP was significantly higher in the group with increasing mean UtA-PI compared with those without (7.9% vs 5.8%; P = 0.002). Logistic regression analysis demonstrated that both third-trimester UtA-PI MoM (odds ratio (OR), 7.35; 95% CI, 4.66-11.6; P < 0.001) and stable or decrease in UtA-PI MoM between the second and third trimesters (OR, 0.43; 95% CI, 0.31-0.60; P < 0.001) were significant independent predictors for the development of HDP.

Worsening of UtA Doppler is associated with HDP, independent of the value recorded in the second trimester. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.