The Hawai'i Supreme Court made the correct, if immensely difficult, call this week when it reversed the manslaughter conviction of a young woman for causing the death of her newborn because she used crystal methamphetamine during her pregnancy.

The ethical and moral questions raised by this case are nearly endless. But in the end, the court made a common-sense decision that best serves the needs of the mother and others in her situation.

The decision itself was rather technical: The mother, Tayshea Aiwohi, could not be found guilty because her unborn child was not a "person," as described by state law, at the time she smoked the crystal methamphetamine.

But the practical impact of the decision will be enormous.

Had the conviction been upheld, pregnant mothers with drug or other problems would be fearful of seeking medical attention because they might face criminal consequences if their child suffered harm.

Those social costs of overturning Aiwohi's conviction were not directly mentioned in the decision. But they were widely discussed elsewhere.

One issue to be determined: If a mother cannot be held liable for behavior that harms her fetus in such a way that it dies or fails to thrive after birth, can a third party be prosecuted for such an act?

While it is rare, it is accepted that an individual who harms a pregnant mother can, in some circumstances, be charged with harm or murder. That concept may no longer hold under the logic of the Aiwohi decision.

In fact, Justice Paula Nakayama, who wrote the majority opinion in this case, raised precisely this issue in a footnote.

There is no easy answer in cases such as this. But on balance, the Hawai'i Supreme Court offered a reasoned response to this most difficult issue.