Oxytocin-induced labor characteristics and uterine activity after preinduction cervical priming with prostaglandin E₂ intracervical gel

Labor characteristics and quantitation of uterine activity resulting from oxytocin induction of labor after intracervical prostaglandin E₂ (PGE₂) gel priming have not been previously reported. Forty-seven women with modified Bishop scores of 5 or less received preinduction priming with 0.5 mg of intracervical PGE₂ gel. Oxytocin was used to induce labor after priming, and uterine activity was quantitated. A matched group of control patients was managed identically but did not receive PGE₂ gel. In the gel group, modified Bishop scores improved significantly and in two patients (4%), priming alone induced labor. No uterine hyperstimulation or fetal heart rate abnormalities occurred during priming. Cesarean sections for all indications and those for failed induction were less common in the gel group. The length of the active phase and the second stage of labor were significantly shorter in the gel group. Uterine activity was similar in both groups. The data suggest a primary cervical action of the gel.