Abstract

PIP: This study assesses whether oral prostaglandin E2 (PGE2) is effective in inducing labor by membrane rupture and simultaneous oxytocic stimulation. 80 unselected patients with a singleton pregnancy were induced at or near term. 50 were primigravidas and 30 multigravidas. PGE2 was given on an increasing dose basis. The initial dose was 0.5 mg and this was repeated at 1 hour if optimal activity was not apparent. Subsequent doses were given 2 hourly until full dilation. Labor was assessed by noting the strength and frequency of uterine contractions, alteration in the state of the cervix, and descent of the presenting part. An epidural catheter was inserted immediately preceding or shortly after amniotomy. If failure ensued, the therapy was discontinued and intravenous oxytocin titration commenced within 30 minutes. Results were that: 1) induction was successful in 43 of the 50 primigravid and 28 of the 30 multigravid patients, 2) the mean induction-delivery interval was 10 hours 18 minutes and 6 hours 20 minutes for each group, respectively, 3) the mean total dose given before discontinuing therapy was 12.8 mg. Side effects included vomiting in 27 patients (34%) and diarrhea in 15 (19%). Failure of induction occurred in 11% of the unselected patients. In general, a relationship appears to exist between the prelabor inducibility score and dose of prostaglandins required to induce labor. Oral PGE2 administration in association with amniotomy was found to be a safe, convenient, and effective method of inducing labor. In patients whose conditions are unfavorable the outcome may be less unsuccessful and associated with side effects; intravenous oxytocin is a preferred means of inducing labor and abortion. Labor is most effectively induced by amniotomy and simultaneous oxytocic stimulation. Oral PGE2 is effective in inducing labor and when administered in association with amniotomy is associated with a short induction-delivery interval, especially in multigravidas.