This nationwide population-based cohort study searched for demographic, comorbid, behavioral, and reproductive risk factors for idiopathic macular hole (MH) development using data provided by the Korean National Health Insurance Service. A total of 4,496,867 individuals aged 50-79 years who participated in the Korean National Health Screening Program in 2013 or 2014 were included. Participants were followed up until December 2018, and incident cases of idiopathic MH were identified. Prospective associations between incident idiopathic MH and various covariates were investigated using multivariable-adjusted Cox proportional hazard models. During an average follow-up period of 4.91 years, 3054 patients were newly diagnosed with idiopathic MHs. Women showed greater risk (hazard ratio of 1.71) and earlier presentation of idiopathic MH than men. Compared to the normal body mass index group, the obese group (≥ 25 kg/m²) showed a significantly lower risk of idiopathic MH. Among postmenopausal women, those with two or more children showed a greater risk of idiopathic MH than those who had not been pregnant, with a hazard ratio of 1.80. In conclusion, idiopathic MH occurred earlier and greater in women. Childbirth were associated with an increased risk of MH development, and obesity was associated with a lower risk of MH.