Pregnancy outcomes of women with congenital uterus didelphys after in-vitro fertilization-embryo transfer.

OBJECTIVE This study investigated the pregnancy and obstetric outcomes of patients with congenital uterus didelphys who achieved clinical pregnancy after in vitro fertilization-embryo transfer (IVF-ET). METHODS A retrospective matched cohort study of 83 infertile patients with uterus didelphys who underwent IVF-ET and achieved clinical pregnancy from January 2005 to December 2018 at our centre was conducted. For each patient in the study group, three control patients with a normal uterine morphology were randomly selected from the database in 2018. Patients in both groups were matched by number of gestational sacs, maternal age, infertility type, cause of infertility, fertilization method, endometrial thickness one day before embryo transfer and number of embryos transferred. The classification of congenital uterine anomalies was based on the American Fertility Society (AFS) system (1988). The pregnancy and obstetric outcomes of the didelphic and control groups were compared. RESULTS Regarding singleton pregnancies, the didelphic group had increased risks of preterm birth (odds ratio (OR), 4.68; rate difference (RD), 0.14; p < 0.001), caesarean section (OR, 2.80; RD, 0.17; p = 0.016) and low birth weight (LBW) (OR, 4.06; RD, 0.10; p = 0.017). Regarding twin pregnancies, the didelphic group showed increased risks of preterm delivery (OR, 4.79; RD, 0.37; p = 0.006), perinatal mortality (OR, 3.16; RD, 0.19; p = 0.043) and LBW (OR, 9.57; RD, 0.35; p = 0.001). Additionally, the didelphic group had a significantly lower live birth rate (61.6% vs. 90.7%, p = 0.008). CONCLUSION The presence of uterus didelphys was associated with significantly increased risks of some adverse pregnancy outcomes compared with pregnancies with a normal uterine morphology in women who underwent IVF-ET. For conceiving twins, uterus didelphys was associated with worse perinatal outcomes. This article is protected by copyright. All rights reserved.