Sublingual versus oral misoprostol for induction of labour in prelabour rupture of membranes at term.

OBJECTIVE To compare the efficacy of sublingual with oral misoprostol for induction of labour in primigravida with prelabour rupture of membranes at term. STUDY DESIGN Randomized controlled trial. PLACE AND DURATION OF STUDY Department of Obstetrics and Gynaecology Unit-II, Sir Ganga Ram Hospital, Lahore, from June 2004 to January 2006. METHODOLOGY The study included 100 primigravidas with singleton pregnancy at term, having pre-labour rupture of membranes and unfavourable Bishop score with no contraindication of induction of labour, vaginal delivery or misoprostol use. The cases were randomized into two equal groups, A and B. Women in the group A were given 100 microg of misoprostol orally at an interval of 4 hours to a maximum of 2 doses while patients in the group B were prescribed the medicine sublingually (50 microg, 4 hourly, maximum of 2 doses). Induction to delivery interval, mode of delivery and fetomaternal complications were main outcome measures of the study. RESULTS In the sublingual misoprostol group (B), 92% women delivered within 12 hours of induction while 84% of subjects delivered in this time period in oral group (A, p < 0.05). There was no failed induction in either group. Regarding dosage, 64% of women delivered with single dose in group B while only 32% delivered with single dose in group A (p < 0.05). The frequency of vaginal delivery was 92% in group B versus 80% in group A, while rate of caesarean section was 8% in the group B and 20% in the group A, which is statistically insignificant. No significant fetomaternal complications were seen in both groups. CONCLUSION The efficacy of sublingual misoprostol in the dosage of 50 microg was comparable to 100 microg oral dose for the induction of labour in the primigravidas at term with pre-labour rupture of membranes.