Which hormone produced in the placenta is critical during pregnancy?

Human placental lactogen (hPL) is a hormone critical during pregnancy that is produced by the placenta. It plays a significant role in preparing the mother’s body for lactation and helps regulate metabolic processes to ensure adequate nutrition for the developing fetus. hPL influences maternal metabolism by increasing insulin resistance, facilitating the mobilization of fatty acids for energy, and ensuring that glucose is available to the fetus.

Estrogen and progesterone, while important for maintaining pregnancy and supporting fetal development, are primarily produced by the ovaries and the placenta in different contexts. Estrogen is involved in the development of female reproductive tissues and the regulation of the menstrual cycle, whereas progesterone is crucial for maintaining the uterine lining and preventing contractions during early pregnancy. However, hPL's unique functions in metabolic regulation make it particularly critical during the later stages of pregnancy.

Aldosterone, a hormone that plays a role in regulating sodium and potassium levels and blood pressure, is not produced by the placenta and does not have a direct role in supporting pregnancy. Therefore, human placental lactogen stands out as the hormone specifically linked to the placenta's role in supporting both maternal and fetal health during pregnancy.