Frequent low-dose misoprostol for termination of second-trimester pregnancy.

Objectives: To determine the efficacy of an application regimen of low-dose frequent misoprostol for second-trimester pregnancy termination.

Methods: A total of 250 women between 12 and 20 weeks of gestation who were scheduled for second-trimester pregnancy termination received 200 microg vaginal misoprostol followed by 100 microg oral misoprostol every 2 h until expulsion of the fetus. Mechanical cervical dilatation with a 16-French Foley balloon catheter was performed if no cervical dilatation was observed after 24 h. The main outcome measures were the delivery rate within 24 h and the factors influencing the interval between the onset of induction and abortion. Secondary outcome measures were the side-effects of the regimen and the total misoprostol dose required.

Results: With application of this protocol, 245 women (98%) delivered within 24 h of induction. The mean (+/-standard deviation) misoprostol dose used was 728+/-297 microg (200-2100 microg). Cox regression analysis revealed that vaginal spotting or nulliparity do not effect the induction-abortion time. On the other hand, using this regimen induction to abortion time tends to be longer in the presence of live fetuses (odds ratio (OR) = 0.45; confidence interval (CI) =0.2-0.8; p=0.008) and pregnancies with gestational age > 16 weeks (OR= 0.59; CI = 0.4-0.8; p= 0.003) when compared with cases of in utero death and pregnancies with a gestational age of 12-13 weeks, respectively. Twenty-seven women (10.8%) experienced one or more side-effects attributable to misoprostol.

Conclusion: The 100-microg oral misoprostol every 2 h following 200 microg vaginal misoprostol is a highly effective protocol for inducing abortion at 12-20 weeks of pregnancy. Cases with live fetuses or pregnancies with older gestational age (> 16 weeks) deliver in a longer time period.