Comparison of 25 and 50 microgram of misoprostol for induction of labour in nulliparous women with postdate pregnancy in Port Harcourt.

BACKGROUND Induction of labor for postdate pregnancy using misoprostol is one of the most common interventions in pregnancy. However, the optimal dose of misoprostol is yet to be determined with previous reports utilizing different dosages. OBJECTIVE The main objective of this study was to compare the effectiveness and safety of 25 μg versus 50 μg of intravaginal misoprostol for induction of labor in nulliparous women with postdate pregnancy. METHODOLOGY This was a prospective study in which 88 nulliparous women with postdate pregnancy were randomly selected to receive either 25 μg or 50 μg of misoprostol for induction of labor. Student's t-test and Chi-square test were used to compare proportions. RESULTS There was no significant difference between the two groups with regard to the induction-vaginal delivery interval between the two doses. The proportion of women delivering vaginally with a single dose of misoprostol (11/40 vs. 23/43, P = 0.01) and vomiting were significantly greater in the 50 μg group. However, there was no significant difference between both groups in terms of the need for augmentation of labor, caesarean section, tachysystole and hyperstimulation syndrome. CONCLUSION Intravaginal administration of 25 μg of misoprostol appears to be as effective, but safer than 50 μg for induction of labor in nulliparous women with postdate pregnancy.