Abstract

Margo S Harrison, Ana Pilar Betrán, Joshua P Vogel, Robert L Goldenberg and A Metin Gülmezoglu

To determine risk factors associated with cesarean birth in nulliparous women with single, cephalic, term pregnancies in spontaneous labor, also known as the Robson Group 1 population. We used the facility-based, multi-country, cross-sectional WHO Global Survey of Maternal and Perinatal Health conducted in 2004 – 2008 to examine the association between woman-, labor/obstetric-, and facility-level characteristics and cesarean birth among Robson Group 1 women using adjusted bivariate comparisons and multivariable logistic regression. We analyzed outcomes of 82,280 women in Robson Group 1, 82% of whom gave birth vaginally (67,698 women) and 18% of whom gave birth by primary cesarean (14,578 women). In adjusted analyses, woman-level factors associated with cesarean birth included age greater than 18 years old, above-normal body mass index (overweight or obese), being married or cohabitating, having attended four or more prenatal visits, and being medically highrisk (p < 0.01). Women who were obstetrically high-risk, were referred during the course of labor, or were at 39 weeks or more gestational age were also more likely to undergo cesarean birth (p-value < 0.001). The facility-level variables associated with method of birth was birth at a facility that had anesthesia service in the facility 24/7, was a teaching facility, required fees for cesarean birth, had electronic fetal monitoring available, and had providers skilled in operative vaginal birth (p < 0.01). Strategies to reduce the frequency of cesarean rates globally include avoidance of medically unnecessary primary cesarean birth. Our analysis of Robson Group 1 women who are at risk of primary cesarean birth highlights the importance of maintaining a healthy pre-pregnancy and pregnancy weight, optimizing management of women with medical problems, and ensuring clear referral mechanisms that ensure women are transferred earlier in the labor course (when warranted). Consideration of removing or reducing fees for cesarean birth warrants further exploration.