Abstract

Prostaglandin E2 tablets were administered intravaginally 505 patients for the induction of labour, without amniotomy, using doses ranging from 1 to 5 mg as a single insertion. The advantages and limitations of this method of induction of labour are discussed.

PIP:

Prostaglandin E2 (PGE2) tablets were administered intravaginally to 505 patients for labor induction, without amniotomy, in doses ranging from 1-5 mg as a single insertion in this randomized, double-blind study conducted at 2 hospitals. Patient mean age, pregnancy duration, and pretreatment Bishop score did not differ significantly among the groups of patients receiving various doses of PGE2. The preinduction Bishop score and percentage of patients successfully induced with 3-mg intravaginal PGE2 tablets were significantly greater, whereas the induction-delivery time was significantly shorter, in patients delivered at Whipps Cross Hospita vs. Charing Cross Hospital (P .05). Plasma levels of 15-keto-PGE2 after the 3-mg dose of PGE2 in 4 selected patients showed wide variation. Labor was not induced in 1 patient with intermittent low plasma 15-keto-PGE2 levels, but it was successfully induced in the other 3, although the patient with the highest plasma level did not become established in labor until the end of the sampling period. Other unpublished studies showed no detectable levels of endogenous 15-keto-PGE2 in patients in spontaneous labor, and so these measurements illustrated the wide variation in plasma levels of 14-keto-PGE2 after a single intravaginal cose. No instances of gastrointestinal side effects or uterine hypertonus were recorded. An increase by 1-mg increments up to 5 mg did not increase the success rate. The effectiveness of this method of labor induction was greater than that of oxytocin without amniotomy and comparable with that achieved using extra-amniotic PGE2, and it is simpler than these 2 methods.