Hydatidiform Mole with Coexisting Normal Pregnancy: A Systematic Review and Individual Participant Data Meta-Analysis.

Background and

Objectives

This study aimed to evaluate obstetric, neonatal, and oncologic outcomes of pregnancies complicated by a hydatidiform mole coexisting with a live fetus (HMCF) carried beyond viability, and to assess the impact of delivery mode on outcomes. Materials and

Methods

A systematic review and individual participant data meta-analysis included HMCF cases progressing beyond 23 weeks. Obstetric and neonatal outcomes, delivery patterns, and oncologic risks were analyzed.

Results

Among 118 pregnancies complicated by HMFC (124 newborns), most were complete moles (87%). Median delivery occurred at 31.6 weeks, with over half before 32 weeks. Common complications included vaginal bleeding (59%), preeclampsia (30%), and hyperthyroidism (18%). Cesarean delivery was performed in 79% of cases, often for mole-related factors, but was not associated with reduced maternal or oncologic risk. Neonatal deaths occurred exclusively in infants delivered ≤32 weeks, highlighting extreme prematurity as the key determinant of survival. Severe preeclampsia was strongly linked to earlier delivery.

Conclusions

With close monitoring, continuation of HMCF pregnancies is possible. Neonatal mortality is mainly driven by prematurity, which appears to be an indirect consequence of HMFC through the development of mola-associated complications. Cesarean section does not appear to improve maternal and oncologic outcomes. Vaginal delivery can be considered when no standard contraindications exist.