Transfer of prostaglandins to the fetus after prostaglandin E2 vaginal pessary administration.

The kinetics of prostaglandins instilled vaginally has been studied in the maternal and fetal circulations, with observation of changes in the stable prostaglandin E2 metabolite 11-deoxy-13,14-dihydro-15-keto-11 beta,16-cyclo-prostaglandin E2. After the administration of prostaglandin E2, 10 mg in a wax-based pessary, concentrations of prostaglandin E2 metabolite in the maternal circulation increased; concentrations in the fetal circulation were higher than those in control subjects. There was a positive correlation between levels found in the fetal and maternal circulations. The implications of these preliminary findings are discussed in relation to the consequences of the use of vaginally administered prostaglandin E2 for cervical ripening and labor induction.