Smoking during pregnancy and congenital limb deficiency.

Abstract

To examine genetic and environmental factors in the origin of isolated congenital limb deficiencies. Case-control study with questionnaire at a family interview of cases of isolated congenital limb deficiencies (six types), negative controls (matched for age, sex, and place of residence), and positive controls (cases of sentinel anomalies). The database of the Hungarian Congenital Abnormality Registry, 1975-84, complemented by three other sources of ascertainment (1,575,904 births). 537 case-control pairs; 392 positive controls. Smoking during pregnancy, congenital limb deficiencies. The adjusted rate of smoking during pregnancy was significantly higher in the mothers of cases of terminal transverse defect (relative odds 1.48; 95% confidence interval 0.98 to 2.23; P = 0.017). This finding supports the hypothesis of vascular disruption as a cause of congenital limb deficiency. Maternal smoking during pregnancy raises the relative odds for terminal transverse limb deficiencies.