The Roles of Growth Hormone, Prolactin and Placental Lactogen In Maternal Metabolism and Fetal Development

Abstract

Human growth hormone (hGH), human placental growth hormone (growth hormone variant or hGH-V), human prolactin (hPRL), and human placental lactogen (hPL, also called human chorionic somatomammotropin or hCS) constitute a family of somatogenic and lactogenic polypeptide hormones that have similarities in structure and biological function. With diverse effects on growth factor production, nutrient metabolism, hormone secretion, and mammary function, the somatogens and lactogens play central roles in growth and sexual development, reproduction, immune function and intermediary metabolism. The metabolic effects of GH, PRL, and PL in the pregnant mother facilitate the delivery of nutrients to the fetus for normal growth and development (, , ). Through induction of maternal insulin-like growth factor I (IGF-I, ) and other growth factors, placental GH (and possibly PL) may stimulate the growth of maternal tissues such as the uterus and placenta (,). And through actions on the maternal breast and hypothalamus (, , ), PRL and hPL prepare the mother for feeding and caring for her newborn young after birth.