Placental Laterality as a Predictor of Pre-Eclampsia: A Prospective Comparative Study From a Tertiary Care Centre in South India

Background: Pre-eclampsia, a multisystem disorder marked by new-onset hypertension after 20 weeks, affects 2–8% of pregnancies and remains a major cause of maternal mortality in low- and middle-income countries. Mid-trimester placental laterality on ultrasound is suggested as a predictor of impaired placentation and future pre-eclampsia. Simple, low-cost predictive tools are crucial for early detection, especially in resource-limited settings. Aims and objectives: To evaluate whether placental laterality detected at 18–24 weeks’ gestation predicts the subsequent development of pre-eclampsia. Materials and Methods: A prospective longitudinal study was conducted among 200 pregnant women whose gestational age is between 18–24 weeks and attending the antenatal clinic of a tertiary care hospital in Madurai. Women presented with pre-existing medical or obstetric comorbidities were excluded. Ultrasonography was used to classify placental location as central or lateral. Participants were followed until delivery for development of pre-eclampsia. Collected data were compiled using MS Excel software, and statistical analysis included Chi-square test, independent t-test, sensitivity–specificity indices, and odds ratios with 95% CI. Results: In our study the central placentation was observed in 81% and lateral placentation in 19% of participants. Pre-eclampsia was developed in 32.5% of the study participants. It was also reported that among women with lateral placentation, 60.5% developed pre-eclampsia compared with 26% with central placentation. Lateral placentation was associated with a significantly increased risk of pre-eclampsia (OR 4.38, 95% CI: 2.03–9.41, p < 0.001). Blood pressure measurements demonstrated a significant rise in both systolic and diastolic pressures for the lateral placenta group by the fourth visit (p = 0.001). Conclusion: Lateral placental implantation detected during the mid-trimester through ultrasound is strongly associated with an increased risk of developing pre-eclampsia. Routine reporting of placental laterality during anomaly scans may enable early risk stratification and closer surveillance of susceptible women.