METHOD: TVS of the cervix was performed before term labor induction. Induction was considered successful if vaginal delivery was achieved within 24 hours; 231 women were available for final analysis.
RESULTS: Analysis of the receiver operator characteristics curve showed an optimal cut-off for cervical length of < or = 20 mm for successful induction. Following multivariate logistic regression analysis, a sonographic short cervix (AOR 5.6; p < 0.001) was an independent predictor of successful induction but not a favorable Bishop score (p = 0.47). Among multiparas with a short cervix, positive and negative predictive values for successful induction were 98% (95% CI 90-100%) and 21% (95% CI 13%-32%) and among nulliparas, predictive values were 69% (95% CI 53%-82%) and 77% (95% CI 64%-87%) respectively.
CONCLUSION: In nulliparas, cervical length can usefully predict labor induction outcome.
METHODS: : Nulliparas with uncomplicated PROM at term, a Bishop score less than or equal to 6, and who required labor induction were recruited for a double-blind randomized trial. Participants were randomly assigned to 3-mg dinoprostone pessary and oxytocin infusion or placebo and oxytocin infusion. A cardiotocogram was performed before induction and maintained to delivery. Dinoprostone pessary or placebo was placed in the posterior vaginal fornix. Oxytocin intravenous infusion was commenced at 2 milliunits/min and doubled every 30 minutes to a maximum of 32 milliunits/min. Oxytocin infusion rate was titrated to achieve four contractions every 10 minutes. Primary outcomes were vaginal delivery within 12 hours and maternal satisfaction with the birth process using a visual analog scale (VAS) from 0 to 10 (higher score, greater satisfaction).
RESULTS: : One hundred fourteen women were available for analysis. Vaginal delivery rates within 12 hours were 25 of 57 (43.9%) for concurrent treatment compared with 27/57 (47.4%) (relative risk 0.9, 95% confidence interval 0.6-1.4, P=.85) for oxytocin only; median VAS was 8 (interquartile range [IQR] 2) compared with 8 (IQR 2), P=.38. Uterine hyperstimulation was 14% compared with 5.3%, P=.20; overall vaginal delivery rates were 59.6% compared with 64.9%, P=.70; and induction to vaginal delivery interval 9.7 hours compared with 9.4 hours P=.75 for concurrent treatment compared with oxytocin, respectively. There was no significant difference for any other outcome.
CONCLUSION: : Concurrent vaginal dinoprostone and intravenous oxytocin for labor induction of term PROM did not expedite delivery or improve patient satisfaction.
CLINICAL TRIAL REGISTRATION: : Current Controlled Trials, www.controlled-trials.com, ISRCTN74376345
LEVEL OF EVIDENCE: : I.