Introduction
Approximately 30% of all births are induced, and the rate is increasing. Reasons for choosing to induce labor include post term pregnancy, pregnancy complications and disease. The increase may be due to updated guidelines showing fewer complications with induction of labor when starting from week 41. Misoprostol is a PGE1 analogue developed for NSAID related gastric ulcers, in obstetrics it is used of-label for induction of labor, medical abortion and management of miscarriage. The drug is cost-effective and can be administered orally, vaginally, sublingually, or buccally. For induction, low repeated doses are used to promote cervical ripening and contractions with CTG monitoring of the fetus. The effect of the drug has been shown to be dose-dependent, and common side effects are mild GI symptoms, fever and chills. How quickly induction leads to delivery depends on cervical maturity. Cervival status is assessed with the Bishop score. The condition of infants is assessed with Apgar at 1, 5 and 10. This literature review is important because induction has become more common, and the choice of administration route affects efficacy, safety and experience. Although we already know that misoprostol can be used to induce labor, several questions remain to be answered, for example, which route of administration is safest, most effective, gives best labor experience for the mother to be administered misoprostol orally versus vaginally. This study addresses precisely these questions.
Aim
The aim of this literature review is to compare oral and vaginal administration of misoprostol for induction of labor, focusing on effectiveness, safety, and women’s experiences.
Method
Five articles were selected via PubMed. The initial search produced 37 hits using “misoprostol”, “administration” and “labor”, filtered to the last 10 years, RCTs and free full text, after adding “oral” and “vaginal”, 11 articles remained, 6 were excluded based on predefined criteria, multiple gestation, studies with concurrent treatment in which the effect of oral or vaginal misoprostol alone could not be distinguished, studies in which the fetus had died, other routes of administration without comparison to oral or vaginal administration, retracted articles, studies solely on women with specific medical conditions, observational and combination studies, and planned induction treatment exceeding 24 hours. Finally, five articles were selected for this literature review.
Results
The studies show that delivery occurs faster with vaginal administration of misoprostol than with oral administration (24.5 hours compared with 44.2 hours). The total number of births within 24 hours was also higher in this group (32% compared with 13%). The caesarean section rate did not differ, and no statistically significant difference could be demonstrated (34% compared with 30%). Women who had exhibited a strong fear of childbirth prior to delivery had a 3,7-fold higher risk of perceiving the birth as negative. Meconium in the amniotic fluid was identified more frequently with vaginal than oral administered misoprostol (33.8% compared with 18.5%). The Apgar score measured 5 minutes after birth was 6 for vaginal administration compared with 4 for oral administration, which was not a significant difference (P=0,54).
Conclusion
Overall, the results support an individualized approach to labor induction. Orally administered misoprostol is considered preferable, as it leads to fewer complications and better patient experience, while its effectiveness dose not differ greatly from vaginally administered misoprostol. Vaginal administration may be chosen when a rapid delivery is the priority.