Objective: To compare the neonatal outcome after a trial of labor (TOL) with that after an elective cesarean section (CS) following one previous cesarean delivery, considering the indication for the first CS.
Design: Population-based cohort study.
Setting: Sweden.
Population: Women with their first two deliveries between 1992 and 2007 registered in the Swedish Medical Birth Registry.
Methods: The risk of low Apgar score (<7 at 5 min) after a TOL was compared with that after an elective CS among 407 159 singletons of women with one previous vaginal delivery and 59 643 singletons of women with one previous CS. The indication for the first-delivery CS was estimated using a hierarchical system. For each indication group, the odds ratio and 95% CI for low Apgar score, TOL vs. elective CS, was computed.
Main outcome measure: Low Apgar score.
Results: The overall risk of low Apgar score was increased in the TOL group (adjusted odds ratio 1.8, 95% CI 1.5-2.1), but the estimate differed substantially by the indication for the first CS (p-value for homogeneity = 0.0001). There was a high risk for low Apgar score after TOL and first CS indication "complications during labor/delivery" (adjusted odds ratio 2.4, 95% CI 1.7-3.4), but low risk with TOL and first CS "without medical indication" (adjusted odds ratio 0.7, 95% CI 0.2-2.1).
Conclusion: Neonatal outcome might be improved by considering the indication for the first CS when choosing between an elective CS or a TOL for the second delivery.
Keywords: Apgar score; cesarean section indication; elective repeat cesarean; perinatal outcome; trial of labor.
© 2013 Nordic Federation of Societies of Obstetrics and Gynecology.