- To characterize risk factors and perinatal outcome following cephalopelvic disproportion (CPD). A retrospective population-based study comparing all singleton deliveries of women with and without CPD, between 1988 and 2010, was conducted. A multiple logistic regression model was used to control for confounders. Out of 242,520 patients, 0.3% (n = 673) were diagnosed with CPD. Using a multivariable analysis, the following obstetric risk factors were significantly associated with CPD: fetal macrosomia (birth weight above 4 kg, OR = 3.3, 95% CI 2.7-4.1, P < 0.001), infertility treatment (OR = 2.6, 95% CI 1.8-3.8, P < 0.001), previous caesarean delivery (OR = 2.2, 95% CI 1.9-2.7, P < 0.001), maternal obesity (OR = 2.1, 95% 1.3-3.4, P < 0.001), and polyhydramnios (OR = 1.7, 95% CI 1.3-2.3, P < 0.001). Deliveries complicated by CPD resulted in Caesarean delivery in 99%, and were more likely to have laceration of the cervix (1.2 vs. 0.3%, P < 0.001), rupture of uterus (0.4 vs. 0.1%, P < 0.001), intrapartum mortality (0.6 vs. 0.1% in control, P < 0.001), and low 1-min Apgar scores (<7; 27.2 vs. 6.5%, P < 0.001). In our population, independent risk factors for CPD include fetal macrosomia, infertility treatment, previous caesarean delivery, maternal obesity and polyhydramnion. These pregnancies had higher rates of adverse perinatal outcomes and accordingly high index of suspicion should be pursued when commencing trial of labor of such pregnancies.