Handedness and maternal smoking during pregnancy

Abstract

Nonright-handedness (NRH) has been attributed to hypoxia-induced brain changes in the fetus and associated pregnancy and birth complications (PBCs). Maternal smoking during pregnancy is known to produce prenatal hypoxia for the fetus, which may result in low birth weight and other PBCs. It was hypothesized that maternal smoking during pregnancy results in a leftward shift of handedness in the offspring. This study compared the distribution of handedness in the offspring of mothers who did and did not smoke cigarettes during pregnancy. Information on maternal smoking, handedness, and PBCs was analyzed for 803 university students. There was a significant shift to the left in the distribution of handedness scores for the offspring of smoking mothers (N = 216), as compared to those of nonsmoking mothers (N = 587). Offspring of smoking mothers also reported significantly more PBCs. Results are consistent with the hypothesis that NRH is associated with pathological neurodevelopment.

Key Words:

• handedness
• ambidexterity
• laterality
• smoking
• obstetric complications
• pregnancy