Smoking during pregnancy and congenital limb deficiency

Abstract

Objective: To examine genetic and environmental factors in the origin of isolated congenital limb deficiencies.

Design: 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).

Setting: The database of the Hungarian Congenital Abnormality Registry, 1975-84, complemented by three other sources of ascertainment (1,575,904 births).

Subjects: 537 case-control pairs; 392 positive controls.

Main outcome measures: Smoking during pregnancy, congenital limb deficiencies.

Results: 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.

Conclusions: Maternal smoking during pregnancy raises the relative odds for terminal transverse limb deficiencies.