ObjectiveTo investigate the effects of β-cell dysfunction on IVF outcomes in women with PCOS.MethodsThis retrospective cohort study includes 1,212 women with PCOS undergoing their first IVF cycle between September 2010 and December 2019. Beta-cell dysfunction was measured by homeostasis model assessment of β-cell function (HOMA-β) index.ResultsIn quartiles of HOMA-β, the incidence of miscarriage dramatically increased from 10.2% (Q1) to 31.1% (Q4) (Pfor trend