Girls boom between tropics

Couples hoping for a baby girl might be best advised to go and live in Africa, if a study to be published today is correct.

It points to big differences in the proportions of male to female births between tropical latitudes and temperate and sub-arctic latitudes.

This gap remains even when local cultural and social preferences - such as the preferences for males in India and China, resulting in the abortion of female foetuses - are taken into account.