Anogenital Distance - in Humans

In Humans

Studies show that the human perineum is twice as long in males as in females, but males have more variance. Measuring the anogenital distance in neonatal humans has been suggested as a noninvasive method to determine male feminisation and thereby predict neonatal and adult reproductive disorders.

Yet another study, by Swan et al., has determined that the AGD is linked to fertility in males, not penis size. An abnormally short male AGD (lower than the median around 52 mm (2 in) have seven times the chance of being sub-fertile as those with a longer AGD. It is linked to both semen volume and sperm count. Those with lower AGD than median also increases in the likelihood of undescended testes, and lowered sperm counts and testicular tumors in adulthood. Babies with high total exposure were ninety times more likely to have a short AGD, despite not every type of the 9 phthalates tested being correlated with shorter AGD.

Swan et al. also report that the levels of phthalates associated with significant AGD reductions are found in approximately one-quarter of Americans tested by the Centers for Disease Control and Prevention (CDC) for phthalate body burdens.

Women who had high levels of phthalates in their urine during pregnancy gave birth to sons who were 10 times more likely to have shorter than expected AGDs.