Prostaglandins in preinduction cervical ripening. Meta-analysis of worldwide clinical experience.

The state of the cervix is an important predictor of success in the induction of labor. A firm and rigid (unripe) cervix increases the likelihood of a failed induction or a prolonged, exhausting labor. Administration of prostaglandins has shown good effects when used for cervical ripening. A meta-analysis of results of studies comparing prostaglandin therapy to placebo or no treatment and comparing different prostaglandin preparations and routes of administration is presented. Currently, prostaglandin E2 appears preferable to prostaglandin F2 alpha based on effectiveness at lower doses, thus minimizing side effects resulting from influences on other body systems. Further research is required to determine the optimal route of prostaglandin administration, although the oral route appears to be unsuitable. Prostaglandins administered vaginally or endocervically appear to offer the best balance of effectiveness and safety.