It's widely known that maternal age causes more genetic defects and it's especially significant later on. The term "hitting the wall" came from the charts. https://www.medrxiv.org/content/10.1101/2021.04.05.21254264v...

I’m basing this on the vibe from a chart someone showed me when I was in the hospital 8 years ago after my son was born. The point is the chances increase exponentially. Found the list now:

Age 20: About 1 in 500 (0.2%) Age 30: About 1 in 270 (0.37%) Age 35: About 1 in 80 (1.25%) Age 40: About 1 in 60 (1.66%) Age 45: About 1 in 20 (5.0%)

Which actually kinda refutes me because 1 in 500 is still a lot.