The Effect of Delaying Childbirth on Primary Cesarean Section Rates
Figure 4
Maternal Age and the Duration of Labor and Risk of Operative Vaginal Birth
(A) Mean duration of spontaneous labor in relation to maternal age (n = 409,703). Bars are 95% CIs of the mean.
(B) Proportion of nulliparous women who required operative vaginal delivery in relation to maternal age among the 518,787 women delivered by a means other than emergency cesarean section. Bars are binomial 95% CIs.