[Resorption of prostaglandin E2 following various methods of local administration for ripening of the cervix and end the induction of labor].

PGEM concentration was determined radioimmunologically in a non-pregnant woman in whom PGE2 was infused intravenously at increasing dosage and in women in whom labour was induced by various methods for local application of PGE2. There was excellent correlation between the amount of PGE2 infused intravenously and the levels of PGEM determined in the peripheral plasma. The following methods of local application of PGE2 were included in the study: 0.4 mg PGE2 gel placed retroamnially by means of a balloon catheter; 0.4 and 0.5 mg PGE2 gel applied endocervically; 1.5 mg PGE2 given pericervically through a portio adapter and 3 mg PGE2 placed intravaginally in form of a single vaginal tablet; also included was a control group where only vaginal examination was performed. Blood was withdrawn before, and then 30 minutes, 1, 2 and 3 hours after PGE2 administration. Mean levels of PGEM in the maternal peripheral plasma showed no change within or between the various groups, with the exception of one patient in the portio adapter group where hyperstimulation occurred. After removal of the adapter PGEM levels dropped to baseline values. It is concluded from the present study that local application of doses currently used to soften the cervix and/or induce labour at term does not give rise to PGEM concentrations in the maternal blood of the same magnitude as achieved by intravenous PGE2 administration.