Figure 16.Shown are the maternal, placental and fetal compartments for estrogen and progesterone synthesis in human pregnancy. The fetal adrenal gland lacks 3β-hydroxysteroid dehydrogenase, but has sulfation and 16α-hydroxylase capabilities. Likewise, the placenta lacks 17α-hydroxylase activity but contains sulfatase in order to cleave the sulfated fetal products. (Modified from (229) , with permission)