Objective: To assess the effect of changing the regimen for second trimester induction of labour from gemeprost to mifepristone/misoprostol.
Design and setting: A retrospective study at a university teaching hospital over the 5-year period 1993-1997. SUBJECTS, METHODS and REGIMENS: 68 patients, 34 in the gemeprost group and 34 in the mifepristone/misoprostol group. The gemeprost group received 1mg vaginally every 3h to a maximum of five doses. The mifepristone/misoprostol group were pre-treated with 600 mg mifepristone orally followed by 800 microg misoprostol vaginally and then 400 microg orally every 3h to a maximum of four oral doses.
Main outcome measures: Induction to abortion interval; delivery within 24h.
Results: The mifepristone/misoprostol group had a lower induction to abortion interval compared to the gemeprost group (median 8.9h versus 19.8h, respectively, p<0.01). The mifepristone/misoprostol regimen was more successful than the gemeprost regimen; 94% versus 68%, respectively, aborted without extra medical or surgical intervention, p=0.02. There were no significant differences in side effects, analgesia requirements or complications between the two groups. Three patients with previous Caesarean sections had a ruptured uterus; two from the gemeprost group and one from the mifepristone/misoprostol group.
Conclusions: The new mifepristone/misoprostol regimen was more effective in second trimester induction of labour. Induction of labour with misoprostol or gemeprost should be used with care in patients with a previous Caesarean section.