[Antonello]

42 is old and at that point she is at a high risk for having children with problems.

I'm kinda curious. What exactly is the percentage of that risk? And how much higher is it than 'normal' aged mothers?

[iowamark]

I'm kinda curious. What exactly is the percentage of that risk? And how much higher is it than 'normal' aged mothers?

The chances of Downs Syndrome increase as the mother ages into her 40's but are still only one or two percent at most.

[Mila]

"I'm kinda curious. What exactly is the percentage of that risk? And how much higher is it than 'normal' aged mothers?"

I found this,

Pregnancy After Age 35, Does the Risk Birth Defects Increase?

The risk of giving birth to a child with a birth defect does increase as the mother's age increases. This is probably due to abnormal division of the egg, called nondisjunction. This leads to unequal chromosomes at the end of division. The traditional age at which a woman is considered to be at high risk for chromosomal abnormalities is 35. Approximately 1 in 1,400 babies born from women in their 20's have Down syndrome; it increases to about 1 in 100 babies born with Down syndrome from women in their 40s.

http://www.webmd.com/baby/guide/pregnancy-after-35