Many parents seem to feel guilty about their own children's disabilities.
When I worked at the California School for the Deaf I noticed that by the time kids were in middle school nearly all of their parents had gotten divorced except for those from Deaf families. I wouldn't be surprised if feelings of guilt were a factor in many of those divorces.
Some special needs are far more difficult to deal with than hearing loss, and there's a lot of stress involved in caring for children who have behavior problems or need lots of medical attention. But guilt should not be an added stress factor. Even if parents made a choice that resulted in prenatal damage or an accident, I hope they can forgive themselves and move on.