I agree with Laura about the donor having another gene. I don't know how they screen for this with donors.I did just see something on tv about a couple who pick a donor with genious IQ . The first child also had high IQ but the second child was born with a disorder that made him unable to speak. So you are probably just taking your chances. Even though babies use to die from cah without meds (and therefore not reproduce) this gene has managed to pop up now anyway. For me personally (I'm a worrier) I would worry how the child might feel if he DID have some medical problem knowing that his parents specifically tried to have a healthy child by a donor. But that is just me. Good luck to you whatever you decide. If I was going to decide on another child at this point in my life,I would try first to adopt a cah child. I have experience now..almost 18 years!! :)