human placental lactogen

…human chorionic gonadotropin (HCG) and human placental lactogen (HPL). HCG, like the pituitary gonadotropins, is a glycoprotein, with a molecular weight of 25,000 to 30,000. HPL is a protein, with a molecular weight variously estimated at about 19,000 or 30,000. One or perhaps both of these hormones, which become detectable…

…hormones—prolactin from the pituitary and somatomammotropin from the placenta. At the end of lactation the mammary glands and areolae return almost but not completely to their state before pregnancy. After menopause the glands atrophy and are largely replaced by connective tissue and fat.