PATTERNS OF UTERINE ACTIVITY - USING OXYTOCIN AFTER INTRACERVICAL PGE(2)

OBJECTIVE: To compare patterns of uterine activity from low-dose oxyto cin begun immediately or six hours after intracervical placement of pr ostaglandin E(2) (PGE(2)) gel for the induction of labor. STUDY DESIGN : A total of 50 nonlaboring women at term with an unfavorable cervix ( Bishop score less than or equal to 4) were given a 0.5-mg dose of PGE( 2) gel. Each was then randomized either to be observed or to receive a low dose of oxytocin (2 mU/min, increased by 2 mU/min at 30-minute in tervals, as necessary). After the six-hour observation, the patient wa s reexamined, and a low dose of oxytocin was either begun or continued . An adequate sample size (21 per group) was calculated for evaluating uterine activity changes. Comparisons were made using chi(2) testing. Student's t test and analysis of variance, as appropriate. RESULTS: T here were no differences between the two groups in maternal race, gest ational age, predose Bishop score, predose uterine activity or indicat ion for induction. Uterine contractions became more frequent (P < .01) and were judged to be more intense (P < .02) and earlier when oxytoci n was used immediately after PGE, placement. No uterine hyperstimulati on or abnormal fetal heart rate pattern was observed that required dis continuation of the oxytocin. The percentages of cases delivering vagi nally within 24, 36 and 48 hours were greater when oxytocin was begun immediately in nullipara (P < .01). CONCLUSION: Low-dose oxytocin may be started immediately after instilling intracervical PGE(2), with sho rtened time until the onset of adequate contractions.