Intravenous Papaverine for Term Prelabor Rupture of Membranes

Women hospitalized in the labor and delivery unit with term premature rupture of membranes at 37 weeks of gestation or later are screened for participation. Eligible participants have no active contractions, cervical dilation of less than 2 cm, vertex presentation, and a duration of membrane rupture between 2 and 12 hours.

Following informed consent, participants are randomized in a 1:1 ratio to receive intravenous papaverine 80 mg diluted in 100 mL of 0.9% saline or 100 mL of 0.9% saline as placebo. The study infusion is administered one hour after initiation of oxytocin.

Treatment allocation is blinded. One study-team member prepares the study solution according to the randomization table, while the remainder of the study team remains blinded to treatment allocation. The primary outcome is the interval from study infusion to delivery.

Inclusion criteria

• Age ≥18 years
• Gestational age ≥37 weeks with term PROM
• No active contractions
• Cervical dilation <2 cm
• Vertex presentation
• PROM duration between 2 and 12 hours

Exclusion criteria

• Previous cesarean delivery
• Contraindication to vaginal delivery
• Known fetal malformation
• Known allergy to papaverine
• Cardiac arrhythmia
• Glaucoma
• Hepatitis or other hepatic disease
• Atrioventricular (AV) block
• Congestive heart disease
• Recent ischemic heart disease
• Increased intracranial pressure
• Active labor, defined as cervical dilation ≥6 cm
• Contraindication to uterine relaxation, including significant uterine bleeding or fetal distress Active infection or chorioamnionitis Use of medications with potentially hazardous interactions with papaverine