They DON'T know. They are reasonably confident that there will be no complications, but there are numerous cases of problems later in life: loss of sensation, infections, psychological issues, etc. Naturally, most doctors would roll their eyes at any mention of complications. But, is it being done to THEIR daughter??? How many doctors have rolled their eyes at other questions we have asked them? How many parents out there trusted their doctor and found out later that something different should have been done? Bone age questions? Liquid cortef questions? Solu-cortef questions? We were once in a hurry to make our daughter look "normal".....it was my father-in-law who calmly said, "you'd better think twice before you cut anything off that baby...". She can choose the surgery later if she wants to.....she's perfect in our eyes, God's eyes, her sister's eyes, etc. Of course we want to save her from EVER getting her feelings hurt....just like any parents would for ANY child...CAH or not....but it wasn't worth the risks we learned about....and it was more important she learned to love herself like she is before we made the choice to take care of things ourselves. We're NOT looking to "solve" this issue......there is no such thing. Someone asked for a viewpoint and we responded.