Which hormone is primarily responsible for stimulating uterine contractions during labor?

Oxytocin is the hormone primarily responsible for stimulating uterine contractions during labor. It is produced in the hypothalamus and released by the posterior pituitary gland. During childbirth, oxytocin levels increase, leading to stronger and more frequent contractions that help facilitate the delivery process. Oxytocin also plays a role in the emotional bonding between the mother and newborn after birth, which adds to its significance in labor and postpartum care.

Other hormones like estrogen and progesterone do play key roles during pregnancy, with estrogen helping to regulate various functions of the uterus and progesterone maintaining the pregnancy by preventing contractions. However, they do not directly stimulate the contractions needed for labor. Prolactin is primarily involved in milk production and does not have a direct role in initiating or sustaining labor contractions. Thus, oxytocin stands out as the essential hormone for promoting uterine contractions during labor.