Induction of labor with intravaginal prostaglandin E2 gel

OBJECTIVE: The aim of our study was to evaluate the optimum dose of intravaginal prostaglandin E2 gel for induction of labor in nulliparous women with a relatively ripe cervix (modified Bishop score 4 or 5). METHOD: One hundred and sixty-seven nulliparous women at term with indications for the induction of labor were treated randomly with two doses of intravaginal 2.0 (group A) or 3.0 mg (group B) of prostaglandin PGE2 gel every 12 h. Data were analyzed by chi2-test and Student's t-test. RESULTS: Of 87 patients 64 went into labor after gel application in group A, compared with 68/80 in group B (73.5% vs. 85.0%) (P = NS). A second gel administration was needed for 9 women in group A and 6 women in group B. More side effects (both local and systemic) were noted in group B than in group A (28.7% vs. 14.9%) (P = 0.03). In particular, more local (hyperstimulation or hypertonus) side effects were noted in group B (13.7% vs. 2.3%) (P = 0.01). CONCLUSION: The vaginal administration of 2.0 mg of PGE2 gel seems to be equally effective as 3.0 mg in terms of labor success rate with a significant lower incidence of side effects.