What are the odds?

While I know our odds for having another baby with Down syndrome are automatically 1:100 because we have already had a baby with DS, I wasn't sure what our odds were for having another baby with heart defects. I did some research, of course, and came across a study that listed the odds based on each of the different heart defects. According to that study, if a mother gives birth to a baby with an AV canal defect, she has a 1:33 chance of having another baby with a congenital heart defect. Other mothers have told me their pediatric cardiologists say those odds are more like 1:12. I just don't know what to think about this. The scientific part of me tells me to worry. But I know that isn't the right thing to do. God is in control. He was in control of Gabby's life from the moment she was conceived. What do I have to worry about? Why should numbers keep me up at night? If God gives us another miracle, the odds that He will take care of that child (and us) are 100:100.