I tested postive as a carrier for Cystic Fibrosis after I became pregnant. I had no idea that Cystic Fibrosis was in the family , but then all the sudden Grandparents and my Dad started telling my horror stories of family members who had died from Cystic Fibrosis and family members with Down Syndrome. Who knows what else I'm carrying. I had no idea any of that stuff was in my blood. If I had known that I was a carrier of CF and knew that Johnny was a carrier of CF , knowing before we were married would have given us pause if we wanted a huge family. We dont so it probably wouldnt have stopped us. But still, knowing you could pass that disease to your child does give anyone pause I'd bet.
It seemed like a long wait when they tested Johnny's blood to see if he was also a carrier. (You need two carrier parents.)
I think its a good idea for couples to know what they are getting into. I think Genetic Counseling and Testing is a good idea before marriage. It does not mean that they cant marry, but at least both couples know what they are getting. You both pass your DNA to the child.