Neonatal morbidity in second twin according to gestational age at birth and mode of delivery.

Abstract

This study was undertaken to assess the risk of neonatal morbidity in the second twins. We carried out a cohort study of 128,219 live born second twins in the United States, 1995 through 1997. The study subjects were divided into 3 groups: second twins delivered by cesarean section after vaginal delivery of the first twin (V-C), both twins delivered vaginally (V-V), and both twins delivered by cesarean section (C-C). The rates of low 5-minute Apgar score, mechanical ventilation, and seizure were higher in the V-C group (8.27%, 13.39%, and 0.31%) than in the V-V (3.07%, 7.51%, and 0.08%) and the C-C (2.66%, 8.53%, and 0.06%) groups. The V-C associated increase in risk remained after adjustment for confounding factors and was more evident at term than preterm. The risk of neonatal morbidity is increased in second twins who had a cesarean section after vaginal delivery of the first twin, especially at term.