Shift in the Sexes.

Japan; United States

This article discusses changes in the male-female ratio in babies born and fetal deaths in the U.S. and Japan. Male birth ratios have, in general, declined in both counties for the last three decades. During the same period, male proportions of fetal deaths increased, but in Japan this ratio is four times higher than in the U.S. According to the author, in the U.S. there are significant racial differences with the proportion of non-hispanic, white males falling while black males showed an increase. The proportion of male fetal deaths rose more among blacks than non-hispanic whites. Researchers speculate that improved health care among black women may be responsible for reducing the overall number of fetal deaths. In Japan, parental exposures to endocrine-disrupting chemicals might be factors undermining the conception and survival of male children.