Those who live in the tropics or have longer days have more baby girls compared with those living in temperate regions of the world, a study reveals.
Research suggests the female foetus is less fragile than the male fetus, which is more prone to the effects of the environment on pregnant women.
At times of extreme environmental stress, including war, the birth rate of girls outnumber the boys.
The study found countries closer to the equator produced significantly fewer boys annually than those at temperate and subarctic latitudes – 51.1% and 51.3%, respectively.
Source: BBC News, 1 April 2009
Chapter: Pregnancy :: 29 April 2009
