How can I increase my chances of having a healthy baby?

Dear Professor Winston
I am considering IVF treatment but I am greatly worried about possible abnormality of my baby as I am 39 and my husband is much older than me.
Could you tell me what tests or things I should/ should not do to ensure the best chances of having a healthy baby.
All advice would be greatly appreciated.
Kind regards,

Dear E,

The risks of an abnormal baby (compared with the risks in a much younger woman) are trivial. The main abnormality is Downs Syndrome and at the age of 39 your risk is around 1 in 100, at age 42 it is about 1 in 85. Actually the main risk is probably miscarriage and by the age of 40 more pregnancies do miscarry.

There is nothing you can do to avoid these risks before conception beyond ensuring a normal healthy diet containing some folic acid; many green vegetables like asparagus and broccoli contain these in high amounts. Some people take extra folic acid in tablet form.

Best wishes
Robert Winston