If you follow that regression of fault, you will end up at God, he who is responsible for everything.
According to your twisted logic, parents suffer having a baby with birth defects, not only by the choices they make or don't make, but by the choices of their parents (as did the baby), and so on, all the way to God.
All your "blame the victim's parents" logic leads you to your main character.
Remind me who created and then punished Adam and Eve?
Birth defects are caused by many things they can be a result of genetics, lifestyle choices and behaviors, exposure to certain medications and chemicals, infections during pregnancy, a combination of these factors, ect.
Many of these drug use, alcohol consumption, smoking during pregnancy, inadequate prenatal care,
untreated bacterial infections can be traced to deliberate human action or inaction. Others like family history of birth defects or other genetic disorders are currently outside the realm of human choice. These are hopefully problems of ignorance and will be resolvable in the near future with our increasing knowledge.
You are correct that you can trace the ultimate cause of all events good and bad to God.
So why did God create a universe where evil, horror, and suffering exist? The problem of evil is a deep question. Here is a short video on the subject I agree with.
Why Does God Allow Evil?
https://www.youtube.com/watch?v=XAexl_loCfg