What hormone is known to cause uterine contractions?

Oxytocin is the hormone that is well known for its role in promoting uterine contractions, especially during labor. It is produced in the hypothalamus and released by the posterior pituitary gland. The primary function of oxytocin in this context is to stimulate the smooth muscles of the uterus, leading to contractions that facilitate childbirth.

During labor, oxytocin levels increase, which helps to regulate the timing and intensity of contractions, ultimately aiding in the delivery process. Additionally, oxytocin also plays a role in milk ejection during breastfeeding, linking it to reproductive functions.

While estrogen and progestin are also important hormones in the reproductive system, their primary roles are related to preparing the uterus for pregnancy and maintaining the uterine lining rather than directly causing contractions. Corticosteroids have different functions, mainly related to managing inflammation and immune responses, and do not play a direct role in uterine contraction.