Risks of neonatal anomalies and obstetric complications in 7378 singleton births after frozen-thawed and fresh embryo transfers in Japan: An analysis using doubly robust estimation.

Purpose: To compare risks of neonatal anomalies and obstetric complications among frozen-thawed embryo transfer (FET), fresh embryo transfer (FreshET), and non-assisted reproductive technology (non-ART) treatments in infertile women.

Methods: This retrospective cohort study analyzed 7378 singleton births (2643 non-ART, 4219 FET, 516 FreshET) from 2013 to 2022. Outcomes were compared using inverse probability weighting regression adjustment, with adjustment for maternal factors.