Do low-risk nulliparous women with abnormal uterine artery Doppler in the third trimester have poorer perinatal outcomes? A longitudinal prospective study on uterine artery Doppler in low-risk nulliparous women and correlation with pregnancy outcomes

Abstract

Objective: To evaluate uterine artery (UtA) Doppler over the course of pregnancy in low-risk nulliparous women and to analyze whether an abnormal uterine artery pulsatility index (UtA-PI) at a 32–34 week’ scan implies poorer perinatal outcomes.Methods: An observational prospective study was carried out including 616 low-risk nulliparous women. Women with any of the following were excluded: fetal abnormalities, multiple pregnancy, and heparin, metformin or hypotensive treatment. Maternal characteristics, mean arterial pressure measurements and UtA Doppler findings were recorded longitudinally.Results: Complete pregnancy data were available for 489/616 women (79.3%). Of these, 385 women had a normal UtA-PI throughout pregnancy (Group 0), while 50 (10.1%) had an UtA-PI > 95th percentile in the first or the second trimester that normalized in the third trimester (Group 1), and 56 (11.4%) had an abnormal UtA-PI in the third trimester (Group 2). We found that the rate of pre-eclampsia (PE) was higher in Group 2 (7/56 versus 4/435, p = 0.003) as was the rate of intrauterine growth restriction (IUGR) (6/56 versus 14/435, p = 0.02).Conclusions: Low-risk nulliparous women with abnormal UtA Doppler findings in the third trimester are at a higher risk of developing PE and having a baby with IUGR.