EXTRA‐AMNIOTIC PROSTAGLANDIN E2 FOR THE INDUCTION OF LABOUR AT TERM

This study examines the possibility that a direct intrauterine route of administration of prostaglandins E2 (PGE2) might be feasible in inducing labor near term similar to that seen in termination of midtrimester pregnancies. 40 patients were studied 26 primigravidae and 14 nulligravidae. Gestational length ranged from 38 to 42 weeks; age range 17 to 41 years. "Inducibility" rating was determined using a modified Bishop scoring system. Patients with inducibility scores of 2 to 5 were considered unfavorable induction prospects while those with scores from 6 to 8 were favorable prospects. PGE2 prepared in normal saline in the concentration of 1.5 mcg of PGE2/ml was infused at the rate of 20 mcg/hour and increased every 15 minutes by 10 mcg/hour until labor was established. Highest dose rate used in the series was 150 mcg/hour. The patients were sedated when necessary. Labor was established when contractions of 35 mm Hg or greater occurred at intervals of 2 1/2 minutes or less and vaginal examination revealed evidence of cervical effacement or dilatation. Labor was established in all cases the mean time interval being 1.9 hours. Mean induction-delivery interval was 9.8 hours (11.7 hours in the unfavorable group; 8.1 hours in the favorable group). Overall mean induction-delivery interval was 9.3 hours excluding 4 cases of Cesarian operation. Mean total dose of PGE2 was 550 mcg. There were no evident side effects on the mothers and their infants. The success rate of this approach compare favorably with conventional methods of labor induction. It may be useful in situations where it is desirable to maintain the fetal membranes intact. Further research should be done on this method to establish its effectiveness and determine its side effects if any.