Retroverted Uterus Revisited: Anatomical and Hemodynamic Insights into Primary Infertility

Background and Objective: The natural orientation of the uterus varies, with a retroverted position historically considered a benign physiological variant. However, its isolated impact on female reproduction remains debated. This study aims to evaluate the association between uterine position (anteverted versus retroverted) and primary infertility using detailed anatomical and sonographic assessments, in the absence of confounding pelvic pathologies. Methods: A prospective, cross-sectional observational study was conducted at a tertiary care center in Maharashtra from April 2023 to December 2024. The study included 90 women (N = 90) diagnosed with primary infertility. Participants underwent transvaginal sonography (TVS) during the early follicular phase. Spatial uterine orientation, cervico-uterine angle, cervical canal length, and uterine artery Doppler indices (Pulsatility Index [PI] and Resistance Index [RI]) were measured. Participants with secondary infertility, male factor infertility, or severe pelvic pathologies like deep endometriosis were excluded. Results: Of the 90 participants, 52 (57.8%) exhibited an anteverted uterus, while 38 (42.2%) had a retroverted uterus, a prevalence notably higher than in the general fertile population. The retroverted group demonstrated a significantly sharper mean cervico-uterine angle (102.4° ± 12.1° vs. 134.6° ± 10.5°, p < 0.001) and an elongated cervical canal (3.6 ± 0.4 cm vs. 3.2 ± 0.3 cm, p < 0.001). Doppler analysis revealed significantly elevated vascular resistance in the retroverted cohort (Mean PI: 2.84 vs. 2.32, p < 0.001; Mean RI: 0.88 vs. 0.76, p < 0.001). Furthermore, women with a retroverted uterus reported higher incidences of severe dysmenorrhea (p = 0.012) and were significantly more likely to experience prolonged infertility exceeding 4 years (p = 0.038). Conclusion: An isolated retroverted uterus is significantly associated with primary infertility. The altered cervical geometry and compromised uterine hemodynamics observed in retroverted uteri may serve as mechanical and physiological barriers to natural conception, suggesting it should be evaluated as a clinically significant anatomical factor in routine fertility workups.