Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, affecting 5%–10% globally. It is frequently associated with menstrual irregularities, hyperandrogenism, infertility, and adverse pregnancy outcomes. Congenital Uterine Anomalies (CUAs), resulting from Müllerian duct development failure, are also closely linked to infertility, recurrent miscarriage, and preterm birth. Although both conditions often coexist clinically, it has long been unclear whether PCOS acts as an etiological factor for CUAs, or whether universal screening for uterine anomalies is warranted in all PCOS patients. A systematic review published in Human Reproduction Openin January 2026 addresses this gap. Utilizing the Bradford Hill causal inference framework, this study integrates data from 21 observational studies and meta-analyses to comprehensively evaluate the causal association between PCOS and CUAs, providing updated evidence for clinical decision-making.
(Source: Human Reproduction Open)
Core Understanding: Is There a Causal Relationship?
This is the first systematic review to apply the internationally recognized Bradford Hill 9-point criteria to assess the causality between PCOS and CUAs. The analysis included 21 studies published between 2000 and 2025 (5 systematic reviews/meta-analyses, 4 case-control studies, 11 cohort studies, and 1 cross-sectional study).
Table 1. Application of Bradford Hill Criteria
Key Conclusions
No Causality: Current evidence does not support a causal relationship between PCOS and Congenital Uterine Anomalies.
Temporal Logic: CUAs are congenital developmental defects present at birth, whereas PCOS typically manifests and is diagnosed after puberty. This chronological discrepancy invalidates a cause-and-effect chain.
Clinical Recognition: Why Does the Prevalence Seem Higher in PCOS?
Observed Association
Meta-analyses indicate that the prevalence of CUAs in PCOS patients is approximately 25.0%, significantly higher than the 5.3% observed in non-PCOS infertile women (OR = 5.96, 95% CI: 1.22–29.17).
True Reasons (Non-Causal)
Detection Bias: PCOS patients have higher rates of infertility and undergo transvaginal ultrasound, hysteroscopy, and other imaging more frequently, leading to higher detection rates of anomalies.
Heterogeneity: Extreme statistical heterogeneity exists across studies (I
2
= 97.56%), rendering results non-reproducible.
Shared Risk Factors: Common underlying factors such as hyperandrogenism and genetic background may link the two conditions, rather than PCOS directly causing uterine malformations.
Diagnostic Pathway: Who Should Be Screened?
Absolute Recommendation: NO Universal Screening
Routine imaging for uterine morphology (TVUS, 3D ultrasound, hysteroscopy, HSG, MRI) is not recommended for PCOS patients without a history of adverse pregnancy outcomes.
Targeted Screening: ONLY for High-Risk Populations
Screening should be reserved for:
Patients with recurrent miscarriage.
Patients with recurrent implantation failure (RIF) undergoing ART.
Patients with a history of preterm birth, premature rupture of membranes, or abnormal fetal presentation suggestive of structural anomalies.
Discouraged Practices
No Laparoscopy: Routine laparoscopy solely for the purpose of "excluding uterine anomalies" is not recommended.
No Routine Inclusion: Uterine anomaly screening should not be a standard item in the baseline evaluation of PCOS.
Management Strategy: Focus on PCOS, Avoid Misdirected Treatment
Core Principles
Do not attribute uterine anomalies to PCOS.
Do not treat PCOS with the goal of "preventing uterine anomalies."
Focus on: Menstrual regulation, ovulation induction, metabolic control, and insulin resistance improvement.
If a Uterine Anomaly is Found
Manage according to the standard clinical pathway for congenital uterine anomalies, regardless of the presence of PCOS.
Clinical Red Lines
Avoid unnecessary surgery, corrective procedures, and medical anxiety arising from excessive screening.
Clinical Implications: Standardization over Over-Medicalization
Evidence Quality: Current evidence ranges from low to moderate quality due to limitations such as inconsistent diagnostic criteria, varying imaging modalities, and selection bias.
Direct Impact on Practice:
Cease the one-size-fits-all practice of "mandatory uterine screening for all PCOS patients."
Adhere to the principle: "Screen only the high-risk, prioritize non-invasive methods, and treat based on symptoms."
Existing conclusions do not alter current routine clinical practice but refine it.
Future Research: Prospective, standardized, large-scale cohort studies are needed for further validation, but these will not change short-term clinical decision-making.
Conclusion
There is no clear causal relationship between PCOS and Congenital Uterine Anomalies. A diagnosis of PCOS alone does not justify routine uterine morphological screening. Clinicians should return to standardized PCOS management, conducting targeted evaluations only for high-risk individuals (e.g., recurrent miscarriage, ART failure). Precision medicine requires reducing over-examination and over-intervention to genuinely improve patient experience and pregnancy outcomes. While more high-quality research is needed, the current evidence base is sufficient to guide clinical practice.
Source: Stefano Palomba, Flavia Costanzi, Giuseppe Seminara, Donatella Caserta, Antonio Aversa, Is polycystic ovary syndrome associated with uterine malformations? A systematic review using Bradford Hill’s causality framework, Human Reproduction Open, Volume 2026, Issue 1, 2026, hoag005, https://doi.org/10.1093/hropen/hoag005
Disclaimer: This article is intended for medical professionals for academic exchange only and does not serve as a basis for specific clinical operations. Clinical decisions must integrate individual patient conditions, institutional resources, and the latest guidelines; multidisciplinary consultation is recommended when necessary.
Editor: Lily