There are currently numerous methods of identifying incurable diseases in fetuses.
However we still have many parents who choose to keep the child even though they know perfectly well it will never be a healthy member of society.
I'm talking about stuff like Down's disease, anencephaly, missing limbs, muscular dystrophy, etc.
I believe that people who choose to keep a sick fetus should be punished in the same way as we would punish someone inflicting a disease on a healthy child. Here's my rationale:
1) The 'default' state of being is 'non-existence', let's rank it at 0.
2) Healthy individuals are on a scale between 0 and 1: some are better off, some are worse off, but most have a good life overall.
3) Extremely sick individuals are somewhere between 0 and -1: the diseases cause immense pain and suffering to the kid and the poor soul will never have a normal life.
By giving birth to someone in the third category you're moving a human being from 0 to a negative state,
rather than giving birth to a healthy child and moving a soul from 0 to a positive state.
If instead of getting abortion and trying again for a healthy child (or adopting) you choose to keep the baby, you have made an action equivalent to inflicting disease upon a healthy child.