A pregnant patient asks the nurse why her provider prescribed progesterone supplements. The nurse explains that progesterone is important because it

A. Prevents uterine contractions to reduce the risk of miscarriage: Progesterone maintains uterine quiescence by relaxing smooth muscle and preventing premature contractions. It also supports implantation and sustains the endometrial lining, reducing the risk of early pregnancy loss and promoting fetal development. B. Stimulates fetal lung development: Fetal lung maturity is primarily stimulated by corticosteroids, not progesterone. Betamethasone or dexamethasone is often administered to enhance surfactant production when preterm birth is anticipated. C. Promotes dilation of the cervix during labor: Cervical dilation occurs due to increased prostaglandin activity and estrogen levels near term, not progesterone. In fact, progesterone helps maintain cervical firmness and closure during early and mid-pregnancy. D. Increases milk production after delivery: Milk production is stimulated by prolactin following delivery when progesterone and estrogen levels drop. High progesterone during pregnancy actually inhibits lactation by blocking prolactin’s action on mammary glands.