Polyendocrine metabolic ovarian syndrome and aneuploidy in early reproduction: a systematic review and meta-analysis

Importance Women with polyendocrine metabolic ovarian syndrome (PMOS) have elevated rates of pregnancy loss, but the contribution of aneuploidy is unclear. Objective We aimed to systematically review and conduct meta-analyses of the effects of PMOS on aneuploidy rates in eggs, preimplantation embryos, and pregnancy losses (PROSPERO: CRD42024590377). Evidence Review PubMed, Web of Science, and Scopus were searched until 4(th)March 2026. Included studies reported aneuploidy rates in women diagnosed with PMOS under the Rotterdam, NIH, or AE-PCOS guidelines and women without PMOS. Studies including parents with structural translocations were excluded. Risk of bias was assessed using a modified Newcastle Ottawa scale and certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Studies were screened, assessed for risk of bias, and assessed for certainty of evidence by two independent reviewers. Disagreements were discussed until a consensus was reached. The primary outcomes in meta-analyses were aneuploidy, complex aneuploidy, and mosaicism, and data were synthesized with random-effects meta-analyses. Findings Twelve of 2,270 studies screened were included. Aneuploidy rates were reported for eggs (one retrospective study), pregnancy losses (one prospective and three retrospective cohort studies; 808 pregnancy losses), and preimplantation embryos (one prospective and six retrospective cohort studies; >5,600 embryos from 1,774 women). Meta-analysis showed that aneuploidies were not statistically different in pregnancy losses (odds ratio [OR]: 0.55, 95% confidence interval [CI]: 0.22 - 1.37) or preimplantation embryos (OR: 0.81, 95% CI: 0.57-1.15) from women of all ages with PMOS compared with those without. In studies that allowed stratification by maternal age, aneuploidy was significantly reduced in preimplantation embryos from women with PMOS <38 years of age (0.66, 95% CI: 0.54-0.80). Complex aneuploidies were decreased in preimplantation embryos from women of all ages with PMOS (OR: 0.59, 95% CI: 0.38-0.91). There were no differences in the odds of mosaicism in preimplantation embryos from women with PMOS (OR: 1.41, 95% CI: 0.83-2.39). This review was restricted by the small number of studies, limited information about maternal ages, and no information regarding parental origins of aneuploidy. Conclusion and relevance Below the age of 38, preimplantation embryos from women with PMOS have significantly lower odds of aneuploidy compared with women without PMOS. This difference may be lost with further advancing maternal age and could suggest alterations to the U-curve of aneuploidy for women with PMOS. Therefore, factors other than embryonic aneuploidy must contribute to the elevated rates of pregnancy loss reported in this group.