First-trimester smoking raises infant defect risk

Women who smoke during the first trimester of pregnancy increase the risk of their offspring developing certain congenital heart defects by 20% to 70%, according to the findings of the Baltimore-Washington Infant Study, the first population-based, case-control study of congenital heart defects conducted in the US.

Researchers from the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, analyzed 2,525 case infants and 3,435 control infants born between 1981 and 1989 in Maryland, Washington, DC, and select counties in Virginia. Odds ratios (OR) for self-reported, first-trimester maternal cigarette smoking and the risk for various types of defects were as follows (all 95% CI): secundum-type atrial septal defects, 1.36 (1.04–1.78); right ventricular outflow tract defects, 1.32 (1.06–1.65); pulmonary valve stenosis, 1.35 (1.05-1.74); truncus arteriosus, 1.90 (1.04–3.45); and levo-transposition of the great arteries, 1.79 (1.04–3.10).

In addition, the results suggested an increased risk for atrioventricular septal defects among infants without Down syndrome (OR 1.50; 95% CI, 0.99–2.29).

Alverson CJ, Strickland MJ, Gilboa SM, Correa A. Maternal smoking and congenital heart defects in the Baltimore-Washington Infant Study. Pediatrics. 2011;127(3):e647-e653.