A good friend of ours caught Cytomegalovirus (CMV) when she was pregnant. And still, she decided not to have an amniocentesis to check if the amniotic fluid (which surrounds and protects a baby during pregnancy) was infected.
She felt really good, and the pregnancy was a dream. (“They did everything just right.”)
Unfortunately, her baby caught the virus as well, and was almost completely deaf when he was born, and still is. He was also (and still is) too small, and he turned to be slightly mentally impaired. And as happens frequently in babies born with congenital CMV, he might be suffering from various other health issues when he grows older (such as severe immune system problems, and symptoms resembling infectious mononucleosis).
The decision not have her amniotic fluid checked is especially painful if you know that mom is actually a medical doctor herself — she knew only too well that she took a big risk.
And now her boy is scarred for life.