Not your fault: where the condition actually comes from
Evidence last assessed 2026-10-14.
In short
- What the research shows
- Genes and insulin biology drive it; it isn't the result of anything you did wrong.
- What it doesn't show
- “Not your fault” is not “nothing matters”, and the exact causes are still open.
- PMOS
See studies and method
What the evidence says
The condition is not caused by anything you did. Its origins are a mix of genetics and insulin biology, with prenatal factors still being studied: it clusters strongly in families, twin studies attribute a large share of the risk to inheritance, and dozens of associated gene regions have been identified.
Twin and family studies find the condition clusters in families, with a large share of risk attributed to inheritance, and genome-wide work has identified dozens of associated gene regions. Insulin resistance (a body-wide trait of metabolism, not a behaviour) plays a central role in it, in lean women as well as heavier ones, and prenatal exposures are also being studied as contributors. The evidence points to inheritance and body chemistry, not to diet, willpower, or any choice you made. A body you did not choose is not a fault.
What this does not show
'Not your fault' is the claim; 'nothing you do matters' is not. Habits can shift symptoms, and that is agency; it is a different statement from cause, and neither replaces the other. The details are genuinely unsettled: which genes, which exposures, how they interact are open research questions, and this states the shape of the evidence, not a mechanism. 'A large share' is 72–79% in one Dutch twin-family study, and heritability describes variation across a population, not how much of your own case is inherited. The prenatal evidence is early: daughters of mothers with the condition are diagnosed more often, and the proposed mechanism comes from studies in mice; it is not a statement about anything you or your mother did in pregnancy. Running in families means your relatives may share it; it is not a prediction for your daughters.
Sources, as Neta holds them
Vink JM, Sadrzadeh S, Lambalk CB, Boomsma DI. Heritability of polycystic ovary syndrome in a Dutch twin-family study. J Clin Endocrinol Metab. 2006;91(6):2100-4. doi:10.1210/jc.2005-1494
People compared with each other · 3,205 participants
Zhao H, Xu Y, Xue B, et al. Multi-ancestry genome-wide association analyses of polycystic ovary syndrome. Nat Genet. 2025;57:2669-81. doi:10.1038/s41588-025-02393-x
People compared with each other
Cassar S, Misso ML, Hopkins WG, et al. Insulin resistance in polycystic ovary syndrome: a systematic review and meta-analysis of euglycaemic-hyperinsulinaemic clamp studies. Hum Reprod. 2016;31(11):2619-31. doi:10.1093/humrep/dew243
Systematic review
Stepto NK, Cassar S, Joham AE, et al. Women with polycystic ovary syndrome have intrinsic insulin resistance on euglycaemic-hyperinsulaemic clamp. Hum Reprod. 2013;28(3):777-84. doi:10.1093/humrep/des463
People compared with each other
Risal S, Pei Y, Lu H, et al. Prenatal androgen exposure and transgenerational susceptibility to polycystic ovary syndrome. Nat Med. 2019;25(12):1894-904. doi:10.1038/s41591-019-0666-1
People compared with each other