[genocidicbunny]

I wonder if perhaps the age when people become parents has an affect on this. Anecdotally, many of the people I know of my generation are having kids later than their parents and grandparents did. There's known correlations to different long-term health issues that we do know of that are related to the age of parents, so if there's a rise in average age of parenthood, it could be related?

Kinda spitballing here though.

[chneu]

Nah. It's been shown that older parents run significantly higher risk for all kinds of genetic and birth defects.

Male sperm begins to degrade sometimes around 30 iirc.

People having kids around 40 years old are significantly more likely to have offspring with a ton of issues. People are having kids much later, now.

This isnt my theory. It's been discussed at length and a google will give tons of info.

[robocat]

  Advancing paternal age was not associated with an increase in risk for either Down syndrome or chromosomal disorders other than Down syndrome.

  Multiple neonatal and pediatric disorders have been linked to older paternal ages.  

  The risk of paternal age has been difficult to estimate and interpret because children often have parents whose ages are similar and likely to be confounded.

From "Disentangling the roles of maternal and paternal age on birth prevalence of Down syndrome and other chromosomal disorders using a Bayesian modeling approach" https://bmcmedresmethodol.biomedcentral.com/articles/10.1186...