to evaluate the association between 2D:4D finger length ratios (representing the prenatal environment, i.e., early androgen exposure) and reproductive indices, such as age at menarche, menopausal age, and length of reproductive period. Retrospective data on age at menarche and menopausal age as well as x-rays of both hands were obtained from 674 Chuvashian women aged 18-70 years (mean 46.32 ± 15.42). Finger and metacarpal length ratios as well as visual classification of finger ratio types, were estimated from the x-rays. We found that a low 2D:4D ratio (radiologically evaluated), a masculine 2D:4D ratio type (visually evaluated), and a putative bioassay for prenatal androgen exposure, were associated with a later menarche and a shorter reproductive period. No association was found with menopausal age.