The contribution of birth defects to spontaneous preterm birth

Abstract

The purpose of this study was to determine if and which birth defects (BDs) are risk factors for spontaneous preterm delivery, and to quantify that risk. A case-control study of spontaneously delivered term (n = 21,093) and preterm (n = 2937; 12.2%) liveborn neonates, between 1996 and 2000, at Ramón Sardá Maternity Hospital of Buenos Aires, was performed. Selected risk factors were compared between term and preterm neonates, and risks of preterm birth in the presence of BDs were evaluated, using stratified and logistic regression analyses. Preterm versus term neonates showed higher rates of most of the selected maternal and neonatal risk factors. The prevalence of BDs among preterm and term neonates was 4.1 and 2.0%, respectively (p < 0.001). Newborns with BDs showed a higher adjusted risk for preterm birth than those without BDs (odds ratio, 2.16; 95% confidence interval, 1.92 to 2.40), with the highest risks for skeletal dysplasias, abdominal wall defects, chromosome, multiple, and minor anomalies. That neonates with BDs are at risk for spontaneous preterm birth, regardless of other factors, should lead to a readjustment of health policies aimed at the reduction of preterm delivery.