The impact of previous cesarean section on the success of future fetal programming pattern

Abstract

The purpose of this study is to examine whether cesarean section in the first pregnancy is associated with the success or failure of programmed fetal growth phenotypes or patterns in the subsequent pregnancy. We analyzed data from a population-based retrospective cohort of singleton deliveries that occurred in the state of Missouri from 1978 to 2005 (n = 1,224,133). The main outcome was neonatal mortality, which was used as an index of the success of fetal programming. Cox proportional hazard and logistic regression models were used to generate point estimates and 95% confidence intervals. Mothers delivering by cesarean section in the first pregnancy were less likely to deliver subsequent appropriate-for-gestational-age (AGA) neonates (OR 0.91, 95% CI 0.89-0.92) when compared with mothers delivering vaginally. Of the 1,457 neonatal deaths in the second pregnancy, 383 early neonatal and 95 late neonatal deaths were to mothers with cesarean section deliveries in the first pregnancy. When compared with women with a previous vaginal delivery, AGA neonates of women with a primary cesarean section had 20% increased risk of both neonatal (OR 1.20, 95% CI 1.05-1.37) and early neonatal (OR 1.23, 95% CI 1.05-1.43) death. Our study suggests that previous cesarean section is a risk factor for neonatal mortality among AGA infants of subsequent pregnancy. Future prospective studies are needed to confirm these findings.