Uterine septum and other Müllerian anomalies in a recurrent pregnancy loss population: Impact on reproductive outcomes

Study Objective: To study the impact of Müllerian anomalies on reproductive outcomes in recurrent pregnancy loss (RPL) population and to evaluate the effect of surgical correction of uterine septum on the odds of achieving live birth in RPL patients with a septate uterus. Design: A retrospective cohort study. Setting: Specialized RPL clinic at a tertiary centre. Patients: RPL patients with ≥ 2 pregnancy losses before 20 weeks’ gestation who attended a specialized RPL clinic. Intervention: We aim to assess the association between a possible risk factor (Müllerian anomalies) and reproductive outcomes, as well as that between having surgery for septate uterus and achieving a live birth. Measurements and Main Results: The primary outcome is live birth rate in RPL patients with Müllerian anomalies compared to those without; secondary outcome measures include rates of full-term live birth, preterm live birth, first and second trimester pregnancy loss, as well as stillbirth. After adjusting for patient age at the initial RPL visit, the number of pregnancy losses, and the presence of any other abnormal recurrent pregnancy loss investigation, the odds of achieving live birth were on average 49.4% lower for patients with a septate uterus compared to those without Müllerian anomalies (OR 0.51, 95% CI 0.30-0.86) in the studied cohort (n = 377). A sub-analysis of 72 patients with septate uterus demonstrated a higher likelihood of live birth in those who underwent septum resection (46/72; 63.9%) compared to those who elected to go for expectant management (26/72; 36.1%), yet this study was underpowered to establish a significant difference (52.2% vs. 34.6%; p = 0.22). Conclusion: In RPL patients, having a septate uterus significantly decreased the chances of achieving live birth. Patients with septate uterus who received hysteroscopic septum division tended to achieve more live birth than those who elected expectant management. However, our study was underpowered to detect a statistically significant difference.