Background: In animals, anogenital distance (AGD) at birth reflects androgen levels during pregnancy and predicts adult AGD. Little is known about AGD in relation to female reproductive characteristics in humans, a question this study was designed to explore.
Methods: We used multiple linear and logistic regression analyses to model the relationships between adult female reproductive system characteristics (e.g. ovarian morphology, menstrual cycle) and two measures of AGD [anus-fourchette (AGD(AF)) and anus-clitoris (AGD(AC))] in 100 college-age volunteers in Spain. Ovarian morphology was classified as having < 6 or ≥ 6 follicles per ovary.
Results: Both AGD measures were positively associated with ovarian follicle number, with AGD(AF) being more strongly associated. Women in the upper tertile of the AGD(AF) and AGD(AC) distributions were more likely to have ≥ 6 ovarian follicles [OR: 6.0 (95% CI 2.0, 17.6) and 3.0 (95% CI 1.1, 8.6), respectively] compared to women in the lowest tertile.
Conclusions: Increased follicular recruitment has been related to excess androgen exposure in utero in toxicological studies. Our results suggest that the androgenic environment during early fetal life may influence reproductive system development, including AGD, in human females.