A simplified preinduction scoring method for the prediction of successful vaginal delivery based on multivariate analysis of pelvic and other obstetrical factors.

Most of the popular preinduction scoring methods were created three decades ago, applied to selected populations and based on analysis of each factor separately. In order to overcome these limitations and to try and create a simple and reliable scoring method, 401 inductions of labor were analyzed. Failure was defined as delivery by cesarean section, regardless the indication. Results of multivariate analysis demonstrated that only two of the five factors used by BISHOP'S method were included (cervical dilatation and fetal head station). Gestational age and parity also constituted important factors and thus the new method incorporates these four factors. The variables among each factor were scored according to their relative risk, obtained from the analysis; dilatation 3 cm or more = 2, dilatation 1-2 cm = 1, fetal head station -1 cm or lower = 1, multiparity = 1, term delivery = 1, closed cervix = 0, station -2 cm or higher = 0, primiparity = 0 and non-term delivery = 0. Comparison of the suggested scoring method and BisHop's method demonstrated that in the low score category our method predicted more accurately cesarean section rate (44.7% and 27.6%, respectively). No difference was noted among the middle or high score groups. More studies among other populations may clarify whether our proposed method really overcomes other methods concerning simplicity, universality and predictability.