Misoprostol, a Prostaglandin E₁ analog, for prelabour ripening of the unfavourable uterine cervix

In the United States approximately 20% of all pregnancies receive therapy to stimulate labour (838,531/4,110,563 pregnancies)^1,2. Of this subpopulation, nearly 40% (10% of all pregnancies) undergo induction of labour for a variety of maternal and fetal indications. As induction therapies are costly, identification of cost-effective therapeutic strategies to enhance the success and cost effectiveness of labour induction are of great interest³. Review of the current literature suggests that misoprostol is an effective cervical ripening and labour induction agent. Previous studies have helped to delineate optimal dosing regimens. However, further prospective randomized clinical trials are needed. Additionally, studies to elucidate the efficacy, safety, and side effects of oral versus intravaginal administration of misoprostol are needed. Likewise, further research is needed to compare the pharmacokinetics of oral versus intravaginal misoprostol administration. The role for misoprostol in cervical ripening and labour induction in VBAC candidates has yet to be evaluated. Finally, larger and more comprehensive prospective clinical trials are needed to identify the most safe, efficacious, and cost-effective cervical ripening regimen to reduce induction times and medical expenditure related to labour induction in women with an unfavourable cervix. More information is needed before recommending misoprostol as an outpatient cervical ripening and preinduction agent.