You may think that age, marriage status, and unprotected sex are factors that determine when a couple has their first child, but a new study suggests there may be a small genetic factor as well. The research from Oxford University found 12 specific areas of the DNA sequence which they believe are related to the age at which we have our first child, and the total number of children we eventually have.
This is the first study to identify specific areas of our DNA linked to reproductive behaviour, authors said. Among the findings: women with DNA variants for postponing parenthood also have bits of DNA code associated with later onset of menstruation and later menopause. In addition, the team found that DNA variants linked with childbearing age are associated with other reproduction and sexual development factors, such as the age when the voice breaks in boys, and the stage women experience their menopause. Genes may also predict the probability that a woman will remain child-free.
According to the study; authors in a recent statement: “An improved understanding of the function of these genes may provide new insights for infertility treatment
In order to identify these reproductive genes, the researchers analysed 62 datasets with information from 238,064 men and women for age at first birth, and almost 330,000 men and women for the number of children they had.
The researchers emphasized that the time that a couple has their first child and the number of children they eventually have is still largely influenced by societal and environmental factors. For example, the researchers calculated that variants in the 12 areas of the DNA together predict less than 1 per cent of the timing at which men and women have their first child and their total number of kids. Still, insights into the genetics involved could help answer questions such as how long a couple can wait before attempting to build a family.
Source: Medical Daily