What is the endocrine function of the placenta?
The placenta besides being the organ by which the exchange of substances among the mother and the fetus is done also has the function of secreting estrogen and progesterone to keep a high level of these hormones during pregnancy. (The placenta still secretes other hormones like human placental lactogen that act similarly to the hypophyseal hormones that regulate reproduction, and HCG, human chorionic gonadotropin.)