Second trimester umbilical artery Doppler in the prediction of adverse pregnancy outcomes in a low risk population: A prospective observational study

Abstract

Introduction: Pregnancies with sustained high resistance uteroplacental circulation have been reported to be at significant risk of adverse outcomes. Assessment of fetoplacental circulation non-invasively using umbilical artery Doppler velocimetry has been suggested as a tool for prediction of perinatal outcomes. Objectives: To determine the utility of second trimester umbilical artery Doppler velocimetry in the prediction of adverse perinatal outcomes (intrauterine growth restriction (IUGR), low birth weight (LBW) and stillbirth). Methods: One hundred and twenty low-risk nulliparous women with viable singleton pregnancies who met the inclusion criteria had umbilical artery Doppler assessment between 22 and 26 weeks gestation. RI≤ 0.76, PI≤ 1.36 and SD ≤ 4.52 were considered as normal. Each participant was monitored till delivery to assess outcome. Diagnostic performance of the Doppler indices for the prediction of adverse pregnancy outcomes were determined. Results: Thirteen (10.8%) women had at least one abnormal Doppler index, abnormal RI was recorded in 1(0.83%) woman, 12(10.0%) had abnormal PI while none had abnormal SD ratio. 50/120 (42%) women had at least one adverse outcome. The sensitivity and specificity of RI for IUGR, LBW and stillbirth were 0.0%, and 99.1%, 0.0% and 98.9% and 0.0% and 99.1% respectively. For IUGR the sensitivity and specificity of PI were 0.0% and 88.8% respectively, while PI had 12.0% sensitivity and specificity of 90.5% for LBW. For stillbirth, the sensitivity and specificity of PI were 66.7% and 91.5%. Conclusion: Late second trimester umbilical artery Doppler velocimetry has a limited role in this low risk population for prediction of adverse pregnancy outcomes. The role of umbilical artery Doppler velocimetry in the prediction of adverse outcomes in high-risk pregnant women may be worthwhile.