Cigarette smoking and the male–female sex ratio

Abstract

Many industrialized nations have reported a significant drop in the male–female sex ratio at birth, although not all (1–7). While this could be due to an increase in the number of female conceptuses surviving, several studies suggest that fewer males are conceived (8) or survive (9, 10) during maternal stress. Fukuda and coworkers (11) found that both maternal and paternal smoking decreased the sex ratio; they suggested that the stress produced by cigarette smoking may be responsible for the decreased sex ratio.