Prediction of mode of delivery in term pregnancies: development of scoring system

Background: The objective of the study was to develop and to validate a scoring system to predict the mode of delivery. Methods: The study involved 835 term pregnancies in labor. Backward multiple logistic regression analysis was carried out in 600 women to identify the factors independently associated with vaginal or caesarean delivery and logistic coefficients were determined to provide weightage for each of the factors. The total score was calculated for each subject. Sensitivity and specificity for vaginal/ cesarean delivery were calculated for different total scores. The validity of the scoring was studied by applying to the same data provider group retrospectively, and on other 235 laboring women prospectively recruited after the development of score. Results: Of 600 women, 61.2% had vaginal deliveries. The significant facilitating factors for vaginal delivery were found to be maternal age of 20-25 years (p=0.02), multiparity (p=0.002), unscarred uterus (p=0.05), rhesus positivity (p=0.05), expected baby weight of 2.5-3.5 kg (p=0.004), and with cephalic presentation, Bishop status> 4, spontaneous onset of labor, clear liquor, and no FHR abnormality (p=0.00).A cut off score of 21 predicted the vaginal delivery with sensitivity , specificity, positive predictive value and negative predictive values of 80%, 65%, 70% and 76%, respectively. Conclusions: The composite score of 21 suggests that woman will most probably have vaginal delivery and that a higher score does not always mean a caesarean delivery.