Low-dose vaginal misoprostol (12.5 versus 25 mu g) for induction of labor at term

PURPOSE: to compare the effectiveness of low doses of vaginal misoprostol (12.5 versus 25 mu g) for induction of labor. METHODS: a double-blind, randomized, controlled clinical trial was performed in Santa Casa de Misericordia de Sobral, from May 2005 to April 2006. Sixty-two term pregnant women, with intact membranes and with indication for labor induction, were included. They randomly received 25 mu g (32) or 12.5 mu g (30) of vaginal misoprostol each four hours, until the maximum of eight doses. Mode of delivery, time between induction and delivery, perinatal complications, and maternal side effects were studied. The control variables were maternal and gestational ages, parity and Bishop score. The statistical tests used were average calculations, shunting line-standards and Student t-test (numerical continuous variables),.2 (categorical variables) and Mann-Whitney test (discrete variables). RESULTS: the two groups, 12.5 and 25 mu g, did not differ in relation to the interval of time between the induction onset and delivery (1524 versus 1212 min, p=0.333), in the frequency of vaginal delivery (70 versus 71.8%, p=0.720), Apgar scores below seven at the fifth minute (3,3 versus 6,25%, p=0.533) and tachysystole frequency (3.3 versus 9.3%, p=0.533). The average of total dose administered was significantly higher in the 25 mu g group (40 versus 61.2 mu g, p=0.03). CONCLUSIONS: vaginal misoprostol in the dose of 12.5 mu g was efficient, with collateral effects similar, to the 25 mu g