Abstract
Background: X-ray pelvimetry is used for evaluation of pelvic inlet generally to diagnose cephalopelvic disproportion (CPD) or contracted inlet. Cesarean section delivery (C/S) is often performed for labor dystocia without CPD or contracted inlet. Here, we examined whether X-ray pelvimetry is useful to decide on mode of delivery in women with dystocia.Method: A total of 1118 pregnant women received X-ray pelvimetry before or during labor. Overall, 205 women with cesarean deliveries for indications except for dystocia were excluded. The remaining 913 women undergoing induction/augmentation were retrospectively investigated. Obstetrical and maternal variables were analyzed by univariate, multivariate or ROC analysis.Results: Among 913 women, 37 (4%), including three with contracted inlet and seven with CPD, gave birth by C/S, whereas 876 gave birth by vaginal delivery. Low maternal height, older age, small obstetrical conjugate, large weight and infant head size were significantly associated with risk of C/S for dystocia. Multivariate analysis revealed that the obstetrical conjugate was an independent variable for risk of C/S. The area under the ROC curve (AUC) and the optimal cut-off values, respectively, were as follows: obstetrical conjugate: 0.68 and 11.7 cm (odds ratio=4.27), transverse diameter: 0.59 and 11.4 cm (odds ratio=1.82), maternal height: 0.70 and 155.5 cm (odds ratio=4.33), and maternal weight before pregnancy: 0.55 and 49.7 kg (odds ratio=1.98).Conclusion: The obstetrical conjugate was an independent variable associated with risk of C/S for dystocia. Additionally, maternal height was comparable to the conjugate in term of diagnostic ability. Our data suggested that routine X-ray pelvimetry was not beneficial to identify women at risk of C/S for dystocia.