Uterine morphology and anomalies in women with and without polycystic ovary syndrome: a systematic review and meta-analysis

STUDY QUESTION Does polycystic ovary syndrome influence the morphology of the uterus and the prevalence of congenital uterine anomalies?SUMMARY ANSWER Available evidence of very low quality shows a possible association between PCOS and some uterine anomalies.WHAT IS KNOWN ALREADY Congenital uterine malformations range from subtle changes in uterine shapes to major morphologic deformities It is postulated that major anomalies result from the abnormal development of Mullerian ducts. However, the etiology of minor deformities is a subject of speculation. Many factors may impact the development of the uterus and its morphology in utero and after birth. Many researchers have reported on the increased prevalence of uterine anomalies in PCOS patients, yet the synthesis of evidence has not been performed.STUDY DESIGN, SIZE, DURATION A systematic review and meta-analysis were performed. We systematically searched the PubMed, Scopus, Embase, and Cochrane Library databases using a complex search strategy including terms such as e.g. 'uterus', 'polycystic ovary syndrome', 'morphology', 'dimensions', 'congenital uterine anomalies', and their synonyms. No language or date restrictions were applied during the literature search. The meta-analysis was based on odds ratio (OR) and 95% CIs using the Mantel-Haenszel random effects model.PARTICIPANTS/MATERIALS, SETTING, METHODS The primary outcomes included uterine malformations, dimensions, and volume, assessed using non-invasive and invasive methods in observational studies comparing PCOS and non-PCOS patients. We excluded case reports, case series, reviews, studies without control groups, and articles reporting exclusively on polycystic ovary morphology. The modified Newcastle-Ottawa scale was used to assess the quality of the included research.MAIN RESULTS AND THE ROLE OF CHANCE Our search retrieved 1929 identified publications, 11 of which were included in the systematic review (10 581 women). The majority of the studies were of poor quality. PCOS was associated with higher prevalence of uterine anomalies (OR = 5.96; 95% CI = 1.22-29.17, P = 0.028). The general count of uterine malformations was significantly higher in the PCOS group (25.0%, 95% CI 6.9-43.2, range 0-49%) than in the non-PCOS group (5.3%, 95% CI 0.5-14.8, range 0-23.1%). The studies had a very high heterogeneity. The scope of uterine malformations possibly linked to PCOS included septate, didelphys, I-shaped (morphology that is not recognized by any main classifications), and dysmorphic uteri. The septate uterus was the most often reported malformation. Altered dimensions included fundal indentation depth and angle. Available research used four classification systems: the most frequently reported was that of the American Fertility Society 1988 (3/11). Six studies did not use any classification. The assessment methods included 2- and 3-dimensional ultrasound, magnetic resonance imagining, hysterosalpingography, laparoscopy, and hysteroscopy.LIMITATIONS, REASONS FOR CAUTION Most of the available studies are of very low quality, use inadequate assessment methods and classifications, and are prone to a high risk of selection bias. Additionally, the differences between PCOS phenotypes and their hormonal aspects are poorly addressed and do not sufficiently explain the etiology of observed changes. The included research displays a varying level of heterogeneity. WIDER IMPLICATIONS OF THE FINDINGS Further research is needed to (i) confirm whether the association between uterine anomalies and PCOS is clinically relevant, (ii) evaluate whether the prevalence of the uterine anomalies varies between women with different hormonal disturbances (e.g. hyperandrogenism), (iii) assess the benefit of any intervention for uterine anomalies in women with PCOS.STUDY FUNDING/COMPETING INTEREST(S) This study received no funding. The authors have no conflicts to disclose.REGISTRATION NUMBER CRD42024527964; http://www.crd.york.ac.uk/prospero/