Objective: To examine the effect of mode of delivery on twin survival, especially among very premature twin births, in a population-based historical cohort study.
Methods: A total of 4428 pairs of live-born twins, birth weight 500 g or greater, were included based on data from vital records of the entire state of North Carolina for the period 1988-1991. The main outcome measures were Apgar score at 5 minutes (less than 7 versus 7 or greater), neonatal death, and infant death.
Results: After controlling for birth weight, twin order, fetal presentation, ethnicity, maternal age, marital status, and adequacy of prenatal care, we found that cesarean delivery was associated with reduced risks (by 50-60%) of low 5-minute Apgar score and neonatal and infant deaths among infants born weighing 500-749 g (P < .05). The cesarean delivery benefited the second twins more than the first twins. Among infants weighing more than 1000 g, the mode of delivery was not associated with either low Apgar score or neonatal and infant mortality.
Conclusion: Our study suggests that cesarean delivery for twins with estimated fetal weights less than 1000 g together with a more liberal use of vaginal delivery for twins with estimated fetal weights more than 1000 g would have a net effect of increasing perinatal survival while lowering the overall cesarean delivery rate.