A point about genetics:
Regardless of the fact that many hereditary disorders are diagnosed too late to be included in family planning, there are limitations to what a genethicist can do for you.
My mother is the carrier of HEDS, a connective tissue disorder that can cause a lifetime of crippling disability- or no particular symptoms at all.
The likelihood of one sufferer passing it on to his or her children is thought to be 50%. So when I inherited the syndrome but my two biological brothers did not, this was the kind of outcome that could have been expected from a genethicist's advice.
What no genethicist will be able to tell you is how it will affect your own life:
My mother has had periods of difficulty but has managed to lead a fairly normal life, worked part time and brought up 4 children, though very much with the help of my strong and indefatigable father.
I have had very little inconvenience from the condition and have in fact worked as a manual labourer: I just had to remember not to support the pick-axe on my weak joints.
Dd has spent most of her life battling chronic pain and has often been dependent on a wheelchair. She is now learning to do without it but is on strong painkillers. We don't know what the future holds. But at the moment she is in education and hoping to train as an actress.
Ds went through a few years of intermittent pain which then stopped. It may never re-occur. He is now a fit and healthy 13yo.
So how could anyone have foreseen which one of us should not have been born?
Even if the woman in question knew she had ADHD (which is not clear) and knew it was hereditary (a big if) and knew what the odds were (not sure anyone does know with ADHD), she still wouldn't know how ADHD would affect her son. And there was no way she could have known that her son would be born with additional learning difficulties.