Trends in cesarean delivery for twin births in the United States: 1995-2008.

OBJECTIVE To estimate trends and risk factors for cesarean delivery for twins in the United States. METHODS This was a cross-sectional study in which we calculated cesarean delivery rates for twins from 1995 to 2008 using National Center for Health Statistics data. We compared cesarean delivery rates by year and for vertex compared with breech presentation. The order of presentation for a given twin pair could not be determined from the available records and therefore analysis was based on individual discrete twin data. Multivariable logistic regression was used to estimate independent risk factors, including year of birth and maternal factors, for cesarean delivery. RESULTS Cesarean delivery rates for twin births increased steadily from 53.4% to 75.0% in 2008. Rates rose for the breech twin category (81.5%-92.1%) and the vertex twin category (45.1%-68.2%). The relative increase in the cesarean delivery rate for preterm and term neonates was similar. After risk adjustment, there was an average increase noted in cesarean delivery of 5% each year during the study period (risk ratio 1.05, 95% confidence interval 1.04-1.05). CONCLUSION Cesarean delivery rates for twin births increased dramatically from 1995 to 2008. This increase is significantly higher than that which could be explained by an increase in cesarean delivery for breech presentation of either the presenting or second twin.