I recall in NER or WMB that members of the White Race are suggested to start families early. The thought being that younger parents have healthier kids, or the ability to make more.
I wanted to submit this material for future considerations. This does not apply for females, but I have read that older females have a higher chance of producing twins, and twins have a higher chance of producing twins:
Title: Older dads make for healthier babiesSource: http://www.marieclaire.co.uk/news/health/178307/older-dads-make-for-healthier-babies.html
The largest study ever conducted into the effects of paternal age has discovered that babies born to young fathers are more likely to suffer birth problems.
Teenage fathers posed the biggest risk, with babies born to men under 20 years old found to be 22% more likely to die during their first four weeks of life, and 41% more likely to die during their first year. Their babies were also found to have a 13% increased chance of a low birthweight and a 15% higher risk of being premature.
No increased risk was found for older fathers, even after the age of 40.
The study was conducted at the Ottawa Health Research Institute in Canada, and looked at 2.6 million sets of parents. To ensure that the age of the mother did not affect findings, all the women were aged between 20 to 29 years old.
Study leader Professor Shi Wu Wen commented on the findings, 'Although the increased relative risks for most outcomes were small, the magnitude of the risk to society could be huge, if the increases we found are truly attributable to paternal age.' He added that the results, 'warranted further investigation.'
Commenting on the findings. Allan Pacey, senior lecturer in andrology at the University of Sheffield suggested the explanation did not lie in biology, but in socio-economic factors.
'A far more convincing explanation for the finding in this study is that older men are simply better able to provide for their pregnant partners than younger fathers', he explains, 'It makes sense that babies born to older fathers probably have a better start to life.'