Risk factors and clinical features associated with retained products of conception confirmed histopathologically

Retained products of conception (RPOC) may lead to maternal morbidity and usually require operative intervention. Initial diagnosis is based on clinical and sonographic presentations; and pathological results usually confirm the diagnosis. Yet, preoperative signs have occasionally false positive results, and may lead to unnecessary intervention. We aimed to identify risk factors for RPOC and signs that increase the probability for a positive pathology. Retrospective study conducted at a single center on data collected between 2010 and 2020. Study cohort included women delivered at >23 weeks. The study group included women who admitted with clinical signs of RPOC within 3 months of delivery. Controls were matched by delivery year at 1:2 ratio and included women who were not admitted within 3 months. Preoperative findings were compared between those with positive and negative pathologic results among the study group. Cases without pathological results were excluded from this analysis. Overall, 516 women were included, 172 and 344 in the study and control groups, respectively. Multivariate backward stepwise analysis revealed that previous RPOC (p=0.002; OR: 96.82; 95% CI: 6.66-14173.72), assisted reproductive technology (ART) (p=0.01; OR: 2.65; 95% CI: 1.22-5.71), HCG > 2.0MoM in the triple test (p=0.001; OR: 4.40; 95% CI: 2.25-8.77) and early postpartum hemorrhage (PPH) (p=0.001; OR: 15.84; 95% CI 5.32-57.37) were significantly associated with RPOC. Of all women in the study group, 112 (65%) had pathological results; 86/112 (76.7%) had positive pathology for RPOC and 26/112 (23.3%) were negative. Women who had termination of pregnancy for fetal malformations or demise and women who had vaginal discharge without bleeding, had significantly lower odds of positive pathology (OR: 0.04; p=0.05 and OR: 0.25; p=0.007, respectively) after adjustment for variables that differed between the groups. Previous RPOC, ART, HCG > 2MoM and PPH were found to be risk factors for RPOC. Termination of pregnancy and vaginal discharge were associated with lower odds of positive pathology.