As I reported last year here, some people born with CHDs start showing symptoms as early as birth and others do not until older childhood or even adulthood. It is important that new parents know, however, what might not be normal in their newborn just to be sure that everything is OK.
For example, I have just recently reconnected with a friend from high school whose daughter was born with some pretty critical CHDs. Her conditions were detected early when at 23 hours old, her doctors and nurses noticed that they couldn't get a pulse in her lower extremities. That lead to further testing and the discovery that she had an interrupted aortic arch, similar to Kyle's. She was not without complications after her surgery to repair the arch, but she is still a fighting little "heart warrior" today.
One of my closest friends recently had a baby girl who is perfectly healthy but had a low pulse-ox and was kept in the NICU until she was almost 3 weeks old before she should go home. They had to make sure that her heart function and other organs were all OK before they could send her on her way. What a relief it was the day she was able to go home with her parents!
I'm not writing this to sound scary, but with almost 1 in 100 babies born with some kind of CHD each year it is a reality that I think all parents should be aware of. The more information you have, the more likely you are to be able to help your child.