It's now been suggested that children of older mothers are often healthier, taller and have a better level of education than children of women who have them younger.
This latest research was carried out by the London School of Economics and suggests that children of women who wait until later in life to become mothers often benefit.
The results were drawn from a study of over 1.5 million Swedish men and women who were born between 1960 and 1991. Their height, physical fitness and educational attainments were judged against the age of their mothers at the time of their birth to draw the conclusion.
The researchers said that the key results they had chosen to monitor - physical fitness and height - were good indicators of overall health, while educational attainments were key lifetime opportunity indicators.
The results showed that mothers who put off having children until their were older, including those who waited until they were 40+, more often had children who were taller and smarter. Siblings from the same families, who had a 10-year age gap or more, were used in the study so researchers could be sure about the importance of maternal age, even when children were brought up in the same household.
In their report the researchers also detailed that as health and educational benefits improve year after year it will always be beneficial to be born later. During their study the scientists denoted that a 10-year difference in when you choose to have your children is accompanied by 10 years of social and environmental changes, which give a child a better start in life.
The author of the report, Mikko Myrskylä explains why this difference is key, saying, 'those twenty years make a huge difference. A child born in 1990, for example, had a much higher probability of going to a college or university than somebody born 20 years earlier.'