Transvaginal cervical length and Bishop score value in predicting successful labor induction with an emphasis on the parity

This study was conducted to explore the value of transvaginal ultrasonography of cervical length measurement, in addition to gestational age, maternal age, parity, Bishop's Score in predicting the method of delivery in pregnancies in which labor is induced with oxytocin at or beyond the 37th gestational week. A total of 148 pregnancies at 40 +/- 3 weeks gestation were included. After labor was induced, 88 women delivered vaginally and 60 underwent cesarean section. These groups were compared with respect to possible predictive parameters of delivery out come. Mean prediction cervical length was 24.5+/-7.9 mm. 108 were primipara and 40 were multipara. The relationship between gestational age, age of women and parity with the model of delivery were evaluated. The first of the two variables were not significant. Primipara (n=57) and multi para (n=31) delivered by vaginally and they were undergone by cesarean 51.9 respectively, the rate of cesarean in the primipara was more than multipara (P=0.007). Sensitivity, specificity, positive, predictive value and negative predictive value of the length of cervix 71.6%, 45%, 65%, 51% and Bishop's score were 53.4%, 66.7%, 72%, 49.4% respectively. Analyses of the Roc curve for cervical length and Bishop's score indicated there is not only significant differences in predicting of model of delivery (P=0.81) In the study the only variable was parity that could predict the success of labor induction but not the age of pregnancy, the age of women, cervical length measurement and Bishop's score.