Prostaglandin in Obstetrics and Gynecology: Physiology, Pharmacology, and Clinical Applications

Abstract

Background: Postpartum hemorrhage remains an important obstetric emergency and may occur when effective uterine contraction is not achieved following placental delivery. Prostaglandins are potent locally acting lipid mediators involved in reproductive physiology, cervical ripening, labor initiation, and regulation of uterine contractility. Their effects are mediated through distinct prostanoid receptors located in the myometrium, cervix, trophoblast, and fetal membranes. Prostaglandin F2 alpha primarily acts through the FP receptor and activates the phospholipase C–inositol triphosphate–calcium pathway, producing powerful myometrial contraction. Carboprost, a prostaglandin F2 alpha analogue, is therefore used as an effective uterotonic agent, particularly when conventional uterotonics are inadequate. Prostaglandin E1 analogues, especially misoprostol, also enhance uterine contraction and offer practical advantages, including ease of administration, stability, and availability through oral, sublingual, buccal, rectal, and vaginal routes. However, the two prostaglandin classes differ in potency, safety, tolerability, and clinical contraindications. Comparing their effectiveness and adverse effects is clinically relevant for selecting an appropriate prophylactic uterotonic agent during elective cesarean section.