Identifying women 45 years and younger at elevated risk for endometrial hyperplasia or cancer

•Recommendations for biopsy in patients ≤45 years old with abnormal uterine bleeding (AUB) are guided by very little data.•In patients ≤45 years old with AUB undergoing biopsy, risk of endometrial hyperplasia/cancer (EH/EC) ranged from <1% to 36%.•Polycystic ovarian syndrome, magnitude of obesity, and race/ethnicity were independent risk factors for EH/EC.•Combinations of risk factors provided more nuanced estimates of estimated risk of endometrial hyperplasia/cancer.•Practical figures demonstrate the range of risk and could be used in shared decision-making regarding endometrial sampling.