Abstract
The relationship between gestational age and congenital defects has not been fully studied. Previous studies have focused on birth weight, an unreliable indicator of gestational age in infants with congenital defects. We investigated the relationship between gestational age and congenital defects using data from the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based surveillance system that actively ascertains birth defects diagnosed in the first year of life among infants whose mothers reside in the metropolitan Atlanta area. For this study, only live-bom singletons were included. We excluded premature infants (less than 37 weeks gestation) with isolated prematurity-related defects, such as undescended testes, inguinal hernia, patent ductus arteriosus, or persistent foramen ovale, from the analysis. Among 264,392 infants with known gestational age born between 1989 and 1995, 7852 (3.0%) had a congenital defect. Premature infants were more than two times as likely to have congenital defects than infants of term (37-41 weeks) gestation (risk ratio = 2.44, 95% C.I. 2.32-2.58). This relationship was evident for nearly all types of congenital defects. The frequency of congenital defects was highest among infants in the 29-32 week gestational age category (RR=3.39). The risk ratios were 2.66, 2.21 and 0.55, in the 20-28, 33-36 and 42-45 week categories, respectively, using the 37-41 week category as referent. Among infants with birth defects, 22% were premature. Recognition of the correlation between prematurity and risk for congenital defects may guide clinical evaluation of these infants. This correlation may have several causes, including (1) congenital defects and prematurity may share some risk factors, and (2) some congenital defects may predispose the pregnancy to premature delivery. Further study of the association between prematurity and congenital defects may provide insight into the basic mechanisms of these relatively common problems.
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Rasmussen, S., Moore, C., Paulozzi, L. et al. Gestational age and risk for congenital defects: a population-based study. Genet Med 1, 44 (1999). https://doi.org/10.1097/00125817-199901000-00021
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DOI: https://doi.org/10.1097/00125817-199901000-00021