Role of Routine Mid-Trimester Uterine Artery Doppler for Surveillance of Placental Mediated Disorders in a Low-Risk Population

Objectives: Abnormalities in the placentation process can increase pregnancy-related complications like pre-eclampsia, placental abruption, intrauterine-fetal death (IUFD) or foetal-growth restriction (FGR). Our objective was to investigate the feasibility of utilising the mid-trimester uterine artery Doppler Pulsatility Index (PI), a non-invasive and effective screening tool, as a diagnostic measure to predict adverse pregnancy outcomes in a low-risk population in South India. Materials and methods: This prospective cohort study was done in the Obstetrics and Gynaecology unit at Amrita Institute of Medical Sciences, South India, between August 2018 and January 2020. Uterine artery Doppler was performed along with the targeted anomaly scan between 18 and 24 weeks of gestation and a relationship was established with pregnancy outcome. Results: Of 100 participants, abnormal uterine artery PI (PI > 90th centile) was found in 13 pregnancies, of which statistically significant association was found with hypertensive disorders (P=0.001), FGR (P=0.064) and preterm birth before 37 weeks (P=0.051). No association was found between abnormal uterine artery PI and neonatal birth weight (P=-0.3), APGAR score (P=0.35) and NICU admission (P=0.078). Conclusion: An early abnormal finding in the doppler study can modify the level of antenatal surveillance required along with appropriate timely interventions, thereby significantly reducing the associated maternal and neonatal morbidity and mortality. When combined with routine ultrasound in pregnancy, such an affordable and straightforward diagnostic modality can improve antenatal care by reducing complications even in a low-risk population.