[New formulation of sublingual misoprostol (25 mcg) for induction of labor]

To determine effectiveness and safety of sublingual misoprostol in tablets of 25 mcg, given every 6 hours for induction of labor in high-risk pregnant women hospitalized in two teaching hospitals in the Northeast of Brazil.

An open, non-randomized clinical trial was conducted, including 40 women with high-risk pregnancies hospitalized at "Maternidade-Escola Assis Chateaubriand" and "Instituto Materno-Infantil de Pernambuco". All of them had gestational age >or= 37 weeks, alive fetus with good vitality and Bishop scores

Active labor occurred in 100% of cases after misoprostol administration. The mean (+/-SD) induction-to-labor interval was 4.8(+/-3.8 hours. Interval from induction-to-delivery varied from 8 to 31 hours with 95% of the deliveries occurring in the first 24 hours with 75% of vaginal deliveries. The frequency of tachysystole was 12.5%. The women did not present relevant side effects neither were there any neonatal complications.

The sublingual tablet of misoprostol of 25 mcg was shown to be effective for induction of labor in high-risk pregnant women. The efficacy and acceptability of this new route should be compared to vaginal administration of misoprostol in future prospective randomized clinical trials.