Fetal Development Weeks 22 Through 26

Week 22

Your baby is covered in sticky white goo. But that's entirely normal! This waxy gunk is called vernix caseosa, and it protects the skin from the watery amniotic fluid. Without the vernix, your baby would be as wrinkled as a prune. A product of the sebaceous glands (which will produce skin-oils later in life), the vernix also protects your baby from skin infections and makes her slippery for an easier trip through the birth canal. Some of the vernix dissolves into the amniotic fluid toward the end of the pregnancy, and the rest will be washed or wiped off in the birthing room after your little one makes his big debut.

If the baby is male, his testes, which have been tucked up inside the pelvis, begin to descend into the scrotum this week. Primitive sperm have already formed in the tiny squiggling passages of the testes, called the seminal vesicles. This little guy is already producing testosterone!