The male/female ratio of fetal deaths and births in Japan

The decline in the male/female ratio of births has not yet been explained. In Japan, the male/female ratio of fetal deaths has been increasing since t he 1970s, reaching over 2.0 in 1996. The increased male/female ratio of bir ths could explain the decrease in the male/female ratio of births during th e past two decades. This trend could suggest the increasing prenatal vulner ability of the male fetus especially at earlier stages of gestation.