Analysis of hemi-uterus pregnancy outcomes in uterine malformations: a retrospective cohort study

Background: The association between uterine malformations and adverse pregnancy outcomes is well recognized. However, studies on adverse pregnancy outcomes based on one kind of anatomical commonality between different uterine anomalies have not been reported. The purpose of this study was to investigate pregnancy outcomes in pregnancies with uterine malformations when the pregnancy is confined to a hemi-uterus. Methods: : A retrospective observational cohort study of women who gave birth at our hospital from 2015 to 2021 was performed. Pregnancies with a unicornuate, complete bicornuate, or didelphic uterus were set as the study group, and pregnancies with a normal uterus were set as the referencegroup. For each case in the study group, pregnancies with a normal uterus were matched by age (± 2 years) in a 1:2 ratio. Data were obtained by reviewing medical records and telephone interviews. Maternal and neonatal outcomes were evaluated and compared between the two groups. Results: : Women in the study group had a higher history of spontaneous abortion and intrauterine fetal death (IUFD). Compared with the reference group, the study group had significantly higher rates of assisted reproductive technology (ART) and cord-around-the neck (CAN). Multivariate logistic regression analyses showed that the study group was at higher risk for preterm birth, preterm premature rupture of membranes (PPROM), malpresentation, and cesarean section. Conclusion: Pregnancies with a unicornuate, didelphic, or complete bicornuate uterus are at higher risk for some adverse pregnancy outcomes than those with a normal uterus.