Any research/numbers on correlation between age of mother @ birth, and birth defects in children? Trying to find some hard data. Thank you!

See the CDC webpage. is the centers for disease control webpage for birth defects, where you will find excellent epidemiologic data and interpretation. As a general rule, women who are older than 35 have an higher risk to bear a child with a birth defect because of a chromosomal imbalance. However, we have become adept at managing these risks. Your OB can explain more.
Yes. I have not looked at the recent numbers, however, there has been a known fact that the older a woman is when pregnant beyond 35 the more likely a child could be more with the defect of being mongoloid.