hi kati. i was in a simular position a few months ago. my son is 9 months old and has classical cah. my brothers wife became pregnant and i was worried. i mentioned it to the endo who spoke to a geneticist who said the chances were so slim for the baby to have cah they she thought it un necessary for my brother to be tested. she also told us that it was not just a simple blood test he would need to have, but that he would need his dna testing against myself, my husband and my son to identify the correct gene, (we are from uk perhaps its different there) hope this helps