The impact of uterine position on conception modes and perinatal outcomes in nulliparous patients.

Abstract Purpose Retroverted uterus affects 15–20% of patients. While typically not a cause for concern, some studies suggest a relationship between a retroverted uterus and subfertility. Study objective was to investigate the association between uterine position and spontaneous conception rates, as well as potential risks for adverse pregnancy outcomes in nulliparous patients. Methods We analyzed data from a retrospective cohort study of 621 nulliparous patients with confirmed pregnancies who received prenatal care at a large medical center between 2006 and 2022. Ultrasound exams documented their uterine position at the beginning of pregnancy. Women were categorized into two groups according to their uterine position. We compared the groups regarding mode of conception (spontaneous/ IVF), pregnancy complications, and vaginal delivery outcomes. Results Compared to patients with anteverted uteri, those with retroverted uteri had a significantly higher rate of conception through IVF (12.3% vs. 6.8%, p = 0.022). IVF indications were similar between groups (p = 0.961). Pregnancy complications, including pre-labor rupture of membranes, miscarriages, and preterm delivery < 37 and < 32 weeks’, were similar. Breech presentation at delivery was comparable between cohorts (~ 6%, p = 0.576). Among patients attempting vaginal delivery (n = 539), cesarean delivery rates were comparable (18.2% anteverted vs. 23.1% retroverted, p = 0.249). No significant differences were observed in other maternal or neonatal outcomes between the groups. Conclusion This study contributes valuable insights into the potential influence of uterine position on pregnancy. While a retroverted uterus does not seem to be a significant risk factor for adverse outcomes, the observed trend regarding its association with IVF pregnancies necessitates further investigation.