Letters to the Editor: Sex proportion of offspring in mothers with cardiac disease

Sex ratio adjustment has become a hot and interesting topic in ecology and production biology, as documentations of sex ratio changes are numerous, and include examples in human and animal species. An increasing number of researches support the idea that exposure to stressful conditions can influence the sexes of offspring produced by humans; a majority of which document significantly fewer males after exposure to adverse conditions such as severe life events, economic disruption (1, 2); but natural disasters such as cardiovascular disease was not assessed.