Snapshot A 30-year-old G1P0 patient presents to the labor and delivery floor at 37 weeks of pregnancy. She has been experiencing contractions for 5 hours and has had premature rupture of membranes. Upon vaginal exam, her cervix is only 1 cm dilated, 10% effacement, and firm cervical consistency. The decision is made to administer a cervical ripening agent to optimize vaginal delivery. Introduction Drugs dinoprostone vaginal suppository Mechanism of action prostaglandin E2 (PGE2) causes increased uterine tone and relaxed cervical smooth muscle Clinical use cervical ripening pregnancy termination Adverse effects abnormal uterine contractions gastrointestinal upset rarely, uterine rupture