Abortion Rights and the Health Exemption for Thieves

The Supreme Court, by a 5-4 decision, has upheld a Federal law banning “partial-birth” abortions. The main objection to this law and other similar attempts to place limits on abortion rights posed by abortion rights activists is that such laws lack exceptions for the health of the mother. Opponents of abortion have objected to writing such health exemptions into the law, seeing them as loopholes which would render abortion laws to be meaningless. Anyone could have an abortion and simply claim that there was a health issue involved. (That health issue could be headaches, throwing up in the morning and looking like a bloated whale.)
The problem I have with the health argument in regards to abortion is that implicitly every law has a health exception. We have laws against stealing but no one is going to put a man in jail because he was starving and therefore stole a loaf of bread. The police are not going to make an arrest, the DA is not going to not prosecute, the jury will not convict and the judge is not going to sentence. This health exemption is not written anywhere but it is self understood. For every law in existence I could construct an emergency scenario which would justify the breaking of that law. There is no need to have exceptions for these emergency scenarios to be put onto the books. If one finds oneself in one of these emergency situations then one commits the crime and trusts in the fact that the legal system will understand that this was one of those emergency situations and make an exception.
If a doctor honestly believes that there is a legitimate health risk if a woman does not have a partial abortion and he is willing, with a straight face, to say this in a court of law then he will be able to conduct that abortion without any fear of going to jail. We can trust in the unwritten law of common sense.