Fertility News
Male Twin Reduces A Woman's Fertility - 06/21/2007
Women who have a male twin are less likely to have children, researchers recently reported. Scientists believe that this is because of the exposure of women to their brother's testosterone for nine months in the womb.
The study results were published after a Finnish report found that women were 25% less likely to have children of their own if their twin was male. Those who did have children gave birth to an average of two fewer babies compared to women who had a twin sister. The study looked at data from the eighteenth and nineteenth centuries.
Researchers have known for some time that hormones in the womb affect fetal development, as determined in studies using rodents; however, up until now, no study had found this relationship in humans.
Scientists believe that women with a male twin have reduced fertility rates because elevated exposure to testoserone in utero can increase their risk of diseases that can lead to fertility problems, such as reproductive cancers.
Source: Reuters
Fertility News Archive