Comparing women who had a cesarean birth to those experiencing vaginal birth, labor was more likely to be longer than 24 hours (8.6% versus 19.1%, p =0.007), and there was a trend towards significance of more infants < 2500 g being delivered by cesarean (2.9% versus 19.1%, p =0.06).
In multivariable modeling of the association of these risk factors (including cervical dilation with borderline significance) with cesarean birth in this subgroup, labor duration of longer than 24 hours (RR 3.6, p =0.07) and likelihood of cesarean birth with each increasing centimeter of cervical dilation on admission (RR 0.8, p =0.07) had borderline significance.
In Group 2, lower birthweight had a trend toward significance, Apgar scores were lower, and maternal antibiotic usage was higher after cesarean delivery.