The Hair Loss Encyclopedia
fine, soft hair covering a fetus during gestation
Lanugo is a fine, soft hair that covers the body of a fetus during development in the womb, typically appearing around the fourth or fifth month of gestation. It usually sheds before birth, but some newborns may still have traces of it, which typically fall off within a few weeks. Lanugo serves to help hold the vernix caseosa, a protective waxy coating, on the skin.