Reproductive outcomes in women with congenital uterine anomalies: a systematic review

Congenital uterine anomalies are common but their effect on reproductive outcome is unclear. We conducted a systematic review to evaluate the association between different types of congenital uterine anomaly and various reproductive outcomes.

Searches were performed using MEDLINE, EMBASE, the Cochrane Library and Web of Science. The Newcastle-Ottawa Quality Assessment Scale was used for quality assessment. Uterine defects were grouped into arcuate uteri, canalization defects (septate and subseptate uteri) and unification defects (unicornuate, bicornuate and didelphys uteri). Pooled risk ratios (RR) with 95% confidence intervals (CI) were computed using random effects models.

We identified nine studies comprising 3805 women. Meta-analysis showed that arcuate uteri were associated with increased rates of second-trimester miscarriage (RR, 2.39; 95% CI, 1.33-4.27, P = 0.003) and fetal malpresentation at delivery (RR, 2.53; 95% CI, 1.54-4.18; P < 0.001). Canalization defects were associated with reduced clinical pregnancy rates (RR, 0.86; 95% CI, 0.77-0.96; P = 0.009) and increased rates of first-trimester miscarriage (RR, 2.89; 95% CI; 2.02-4.14; P < 0.001), preterm birth (RR, 2.14; 95% CI, 1.48-3.11; P < 0.001) and fetal malpresentation (RR, 6.24; 95% CI, 4.05-9.62; P < 0.001). Unification defects were associated with increased rates of preterm birth (RR, 2.97; 95% CI, 2.08-4.23; P < 0.001) and fetal malpresentation (RR, 3.87; 95% CI, 2.42-6.18; P < 0.001).

Canalization defects reduce fertility and increase rates of miscarriage and preterm delivery. None of the unification defects reduces fertility but some are associated with miscarriage and preterm delivery. Arcuate uteri are specifically associated with second-trimester miscarriage. All uterine anomalies increase the chance of fetal malpresentation at delivery.