Placental Pathology and Maternal Risk Factors for Stillbirth: A Case-Control Study

Background Fetal death is the delivery of a fetus with no sign of life, as indicated by the absence of breathing, heartbeat, pulsation of the umbilical cord, or definite movement of voluntary muscles. Nearly 2.6 million stillbirths are estimated to occur worldwide every year. Almost all of these (98%) stillbirths occur in low- and middle-income countries. About one-sixth of the stillbirths globally were recorded in India in 2019, making it the most burdened country in the world. In light of this, we conducted a study to identify the placental pathologies and maternal factors associated with stillbirth. Methodology A case-control study was conducted at the Department of Obstetrics & Gynecology, Veer Surendra Sai Institute of Medical Sciences and Research (VIMSAR), from June 2022 to May 2023. Cases included pregnant women with a gestational age of 28 weeks or more who delivered a stillbirth infant at VIMSAR, and controls included gestational age-matched deliveries with live birth. Consent to participate in the study was obtained before enrolment. The final sample size was 79 cases and controls. The chi-square test was performed for bivariate analysis, and logistic regression was used for multivariate analysis. Results In our study, we found a significant association between maternal age of more than 30 years (odds ratio (OR) = 3.01, 95% confidence interval (CI) = 1.91-4.22, p = 0.012), maternal education (with up to the primary level or less: OR = 6.19, 95% CI = 2.92-7.87, p = 0.012), history of addiction (tobacco chewing: OR = 5.58, 95% CI = 3.71-7.11, p = 0.03), and the number of antenatal visits (no visit: OR = 6.87, 95% CI = 2.91-7.79, p = 0.019) with an increased risk of stillbirth. Among the obstetrical complications, pre-eclampsia/eclampsia (OR = 3.87, 95% CI = 1.98-5.11, p = 0.001), premature rupture of membranes (PROM)/preterm premature rupture of the membranes (PPROM) (OR = 2.49, 95% CI = 1.31-3.91, p = 0.03) and antepartum hemorrhage (APH) (OR = 2.66, 95% CI = 1.65-3.58, p = 0.02) were found to be significantly related with stillbirth. Among placental pathologies, uteroplacental vascular pathology (OR = 7.39, 95% CI = 3.01-8.97), acute chorioamnionitis (OR = 3.35, 95% CI = 2.11-5.21), chronic inflammation (OR = 2.33, 95% CI = 1.91 4.17), calcific changes (OR = 4.46, 95% CI = 2.56-6.01), and retroplacental clots (OR = 9.95, 95% CI = 4.39-11.71) were associated with stillbirth. Conclusions In our study, advanced maternal age, absence of antenatal visits, low level of education, tobacco addiction, pre-eclampsia/eclampsia, APH, and PROM in pregnancy were the major risk factors associated with stillbirth. Uteroplacental vascular pathology, chorioamnionitis, chronic inflammation, retroplacental hematoma, and calcific changes were the most significant placental lesions associated with stillbirth.