Temperament and neonatal risk in full-term and preterm combined vaginal/cesarean section twin pairs.

Ten pairs of full-term and 8 pairs of preterm twins from combined vaginal and Cesarean section deliveries were evaluated on measures of neonatal temperament, developmental status, and integrity to determine if the Cesarean-delivered infant was compromised relative to its vaginally-delivered twin. There were no significant differences, within groups, between the vaginal and Cesarean section infants on measures of risk and developmental status. Analyses of variance of paired comparisons performed on the temperament measures indicated that, for the full-term group, there were no significant differences in ratings between vaginally and Cesarean-delivered infants. In contrast, preterm infants delivered by Cesarean section were more active during sleep than their vaginally-delivered cotwins. This finding, together with previous findings demonstrating a relation between this measure and temperament at 9, 18, and 24 months of age, suggested that the preterm Cesarean-delivered infant may be at risk in this area when compared with its twin. In the main, however, the results demonstrated that infants born by Cesarean section following vaginal delivery of their twins were not more compromised than their twin siblings.