Preterm birth and congenital heart defects: a population-based study.

BACKGROUND AND OBJECTIVES Preterm birth (PTB) and congenital heart defect (CHD) are 2 major causes of mortality and disability of perinatal origin. There are limited data on the relation between CHD and PTB. Our objective was to use population-based data to estimate the risk of PTB in newborns with CHD and to study specific associations between categories of CHD and PTB. METHODS We used data from a population-based cohort study of CHD (EPIdémiologique sur le devenir des enfants porteurs de CARDiopathies congénitales study), including 2189 live births with CHD (excluding isolated atrial septal defects) born between 2005 and 2008. We categorized CHD by using an anatomic and clinical classification. Data from the French National Perinatal Survey of 2003 were used to compare PTB in the EPIdémiologique sur le devenir des enfants porteurs de CARDiopathies congénitales study to that of the general population. RESULTS Of the newborns with CHD, 13.5% were preterm. The odds of PTB were twofold higher than for the general population (odds ratio 2.0, 95% confidence interval 1.6-2.5), essentially due to an increase in spontaneous PTB for newborns with CHD. The risk of PTB associated with CHD persisted after exclusion of chromosomal or other anomalies. There were significant variations in risk of PTB across the categories of CHD after adjustment for known risk factors of PTB and factors related to medical management of pregnancy and delivery. CONCLUSIONS We found a higher risk of PTB in newborns with CHD, which was essentially due to spontaneous PTB. Risk of PTB varied for categories of CHD. Our finding may be helpful for generating hypotheses about the developmental links between CHD and PTB.