Maternal and fetal outcomes in women with uterine congenital abnormalities: a systematic review and meta-analysis.

Abstract

Background: Congenital uterine anomalies (CUA) are structural abnormalities resulting from disrupted Müllerian duct development and have been associated with adverse reproductive and obstetric outcomes. However, the magnitude of these risks and variation across anomaly subtypes remain incompletely defined.

Objectives: To evaluate the association between CUA and adverse maternal and fetal outcomes and to examine subtype-specific risk patterns using contemporary evidence.

Methods: We conducted a systematic review and meta-analysis of studies identified from MEDLINE, Web of Science, and Cochrane CENTRAL. Eligible studies compared women with imaging- or surgically confirmed CUA to those with normal uterine anatomy and reported at least one predefined obstetric outcome. Random-effects meta-analyses were used to estimate pooled odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was assessed using the I² statistic, and certainty of evidence was evaluated using GRADE.

Results: Thirty studies comprising over 3.3 million pregnancies were included. Compared with women with normal uterine anatomy, CUA were associated with increased odds of miscarriage (OR 1.45, 95% CI 1.13-1.86), preterm birth < 37 weeks (OR 3.74, 95% CI 1.99-7.02), fetal malpresentation (OR 19.28, 95% CI 6.27-59.24), and caesarean delivery (OR 3.52, 95% CI 1.11-11.09). Heterogeneity ranged from low to high across outcomes (I² 0.0-94.9%). Subtype-specific patterns were observed, with septate uterus more frequently associated with miscarriages, and unicornuate and didelphys uteri associated with higher risks of preterm birth and malpresentation. Sensitivity analyses supported the robustness of findings for preterm birth.

Conclusions: Congenital uterine anomalies are associated with increased risks of adverse pregnancy outcomes, with distinct subtype-specific patterns. Septate uterus is primarily associated with early pregnancy loss, whereas unicornuate and didelphys uteri are more strongly associated with later gestational complications. These findings support classification of pregnancies complicated by CUA as high risk and highlight the need for tailored antenatal surveillance and subtype-specific clinical management.