If a person is born with a pre-existing condition, how does the person get health insurance?

Can they get insurance through the private market, or are all pre-existing conditions covered through Medicare or Medicaid or (S)CHIP regardless?
--------------------
If the parents have coverage then the baby will be added to that plan provided the parents add the baby to the plan. They usually have 30 days from the time of birth. If they forget then they're out of luck. This is also part of the reason why pregnant folks can't get coverage. Not only do the insurance companies not want to pay for the birth -- they also want to avoid taking the risk that the baby is a premie or otherwise going to be expensive. All reasons why you never want to be without.
Source