Wow Congrats!!! You must have one full house!!! I am sure never a dull moment!
I totally understand your fear. My son Cooper was born with HLHS (heart condition) and he passed away 7wks later after a good fight and several open heart surgeries. He was my first and my world. I was beyond hurt......some how by the grace of God I became pregnant again 4 months later. Which was a miracle in it self being that it took me two years to conceive Cooper.
Needless to say my entire pregnancy I was so afraid that my son would have HLHS too, there was a 2% chance just like you! But 9 months later his little bro Cruz Cooper was born perfect!!!
I am not familiar with CDH but I can tell you this, your doctor will stay on top of everything!!!!! And so will that beautiful little Angel on your side! I bet your little girl is so happy for you guys!!!!
I am the creature of Baby Angels ( a support group on MedHelp feel free to join and share your story if you like)
I'd stay positive and focus on the fact that there is a 98% chance your babies won't have CDH. Being positive and taking the vitamins & eating healthy & practicing healthy habits are all great things you can do for you and the babies. Also, try and rest, rest, rest. So hard when you already have 6 kids, but see if you can get some help so that you can enjoy the pregnancy and not be too worn out. The fact that your body already knows what it is doing will be a help (I found each pregnancy to be easier). Just take it easy and try and rally some troops around to help you now (and help you with the other children) and after the babies are born so you can enjoy this time and the weeks after their birth without getting too exhausted. All the best!
I'd say the chances are very slim. Congrats on your pregnancy