RESUMO
OBJECTIVE: To identify the clinical and sonographic parameters which predict the likelihood of successful labor induction in preterm women. METHODS: This prospective observational study enrolled 103 consecutive preterm women (<37 weeks gestation) with singleton gestations scheduled for induction of labor. Transvaginal ultrasound for measurement of the cervical length was performed and the Bishop score was determined by digital examination. The parameters studied were gestational age at induction, parity, maternal age, Bishop score, sonographic cervical length, and current body mass index (BMI). Univariate and multivariate statistical methods were used for data analysis. RESULTS: Successful induction of labor occurred in 45 (44%) of women. Multiple logistic regression analysis identified parity, maternal BMI, and gestational age at induction as the independent predictors of successful labor induction in preterm women, although gestational age did not reach statistical significance (P=0.056). However, maternal age, sonographic cervical length, and Bishop score did not provide independent contribution to success of induction. CONCLUSION: In preterm women undergoing induction of labor parity, maternal BMI, and gestational age at induction were independent parameters in predicting successful induction of labor. However, sonographic cervical length and Bishop score had poor predictive values for success of labor induction.