A Comparison of Oral Misoprostol and Vaginal Dinoprostone Pessary in Induction of Labor at Term

Ko, Ok Jin; Kim, Se Eun; Seo, Eun Sung; Song, Seung Eun; Choi, Suk Joo; Oh, Soo Young; Kim, Jong Hwa; Roh, Cheong Rae

Abstract

OBJECTIVE
The aim of this study was to compare the efficacy and safety of oral prostaglandin (PG) E1, misoprostol, and vaginal PGE2, dinoprostone pessary, in the induction of labor at term.
METHODS
From March 2004 to March 2006, we retrospectively analyzed 175 women who underwent labor induction at term with an unfavorable cervix (the Bishop score=4). Women in the misoprostol group (n=72) received 100 microgram oral misoprostol and the second dose could be repeated every 6 hours if the Bishop score remained at 4 or less. Women in the dinoprostone group (n=103) received 10 mg vaginal dinoprostone pessary. Intravenous oxytocin, if necessary, was administrated 6 hours after the last dose of oral misoprostol or removal of the dinoprostone pessary.
RESULTS
Mode of delivery and indications for cesarean delivery were similar in the two groups. The interval from PG administration to active phase of labor (median [range], 9.6 [3.0~37.2] hr vs. 12.0 [1.8~41.7] hr, p<0.05) and vaginal delivery (median [range], 12.7 [3.2~38.4] hr vs. 15.5 [3.3~ 37.1] hr, p<0.05) were shorter in the misoprostol group than the dinoprostone group. However, delivery within 12 hours and within 24 hours after PG administration was similar in the two groups. Uterine hyperstimulation syndrome occurred in 5 (6.9%) women in the misoprostol group and in none in the dinoprostone group (p<0.05). The neonatal outcome was not different between the two groups.
CONCLUSION
Overall, oral misoprostol is as effective as vaginal dinoprostone pessary for induction of labor at term, but it is associated with shorter labor induction time and higher risk of uterine hyperstimulation syndrome.