Role of second-trimester uterine artery Doppler indices in the prediction of adverse pregnancy outcomes in a low-risk population

Objective To evaluate use of second-trimester uterine artery Doppler velocimetry to predict adverse pregnancy outcomes. Methods A prospective longitudinal study among low-risk nulliparous women with singleton pregnancies attending Ekiti State University Teaching Hospital, Nigeria, between July and December 2017. Uterine artery Doppler indices were measured at 22-26 gestational weeks. Resistance index (RI) of 0.58 or less and pulsatility index (PI) of 1.6 or less were considered normal. The ability of Doppler indices to predict adverse pregnancy outcomes was determined. Results Among 120 women, 73 (60.8%) women had at least one abnormal Doppler index and 50 (41.7%) at least one adverse pregnancy outcome. For pre-eclampsia, sensitivity and specificity of RI were 40.0% and 37.3% (area under curve [AUC], 0.28), and those of PI were 20.0% and 89.1% (AUC, 0.33) respectively. For intrauterine growth restriction, sensitivity and specificity of RI were 23.1% and 34.6% (AUC, 0.22), and those of PI were 0% and 86.95% (AUC, 0.48), respectively. For low birthweight, sensitivity and specificity of RI were 60.0% and 38.9% (AUC, 0.54), and those of PI were 20.0% and 90.5% (AUC, 0.55), respectively. Conclusion Late second-trimester uterine artery Doppler velocimetry had limited ability to predict adverse pregnancy outcomes in a low-risk population.