Prelabor cesarean delivery for twin pregnancies close to term is associated with reduced mortality

Abstract

Objectives: To examine short and longer term outcomes for twins born at or near term, comparing prelabor cesarean delivery (CD) to birth after trial of labor. Methods: A retrospective cohort of twin pregnancies delivered ≥ 36 weeks gestation from 2000 to 2009. Pregnancies with an antenatal death, lethal anomaly, birthweight discordance ≥25% or birthweight <2000 grams or >4000 grams were excluded. Outcomes included severe hypoxia, stillbirth and neonatal death, and hospital admissions or death during the first 5 years of life. Results: 45.3% of 7099 twin pregnancies were delivered by prelabor CD. Compared to delivery after labor, prelabor CD was associated with significantly reduced risks of adverse infant outcomes including severe birth hypoxia (0.08% vs. 0.75%, RR 0.10, 95% CI 0.04-0.26), neonatal death (0.00% vs. 0.15%, RR 0.05, 95% CI 0.00-0.82), and death up to 5 years of age (0.16% vs. 0.40%, RR 0.41, 95% CI 0.20-0.85). Whereas total mortality for first twins was similar after labor (0.15%) compared to prelabor CD (0.16%), total mortality was four times more common in second twins born after labor (0.64%) compared to second twins born after prelabor CD (0.16%). Conclusions: Twin pregnancies at and beyond 36 weeks who are delivered after labor have increased risks for birth outcomes associated with hypoxia. These risks do not result in increased mortality in the first twin, but second twins have significantly increased mortality up to 5 years of age. However, the absolute mortality rate for relatively uncomplicated twin pregnancies born at or near term is low.