The decision told a lower court to reconsider its ruling that struck down, in its entirety, a New Hampshire law that fails to include such an exception. "We try to limit the solution to the problem," Justice Sandra Day O'Connor said in her opinion for the court, instructing the lower court to consider invalidating the law only as it applies to those few teenagers who need an immediate abortion for medical reasons.
"We do not revisit our abortion precedents today," Justice O'Connor declared in the opening words of what is likely to be her last opinion for the court. The studiously bland 10-page opinion carefully sidestepped the abortion debate that has been a prominent feature of public discourse about the court's future.
The hiatus may be brief, however. At their conference on Friday, the justices are scheduled to take up the Bush administration's appeal of a lower court ruling that declared unconstitutional a federal law, the Partial-Birth Abortion Ban Act of 2003.
That case, on which the court had deferred action until the New Hampshire case was decided, presents issues that may not be so easily avoided. Further, the federal case, if the court agrees to hear it, would be argued after Justice O'Connor's departure. She was part of the 5-to-4 majority that struck down a Nebraska precursor of the federal law in 2000, so her successor, who is likely to be Judge Samuel A. Alito Jr., could cast the deciding vote.
In the New Hampshire decision on Wednesday, the justices accepted the finding by two lower federal courts that the New Hampshire law was constitutionally deficient in not making explicit provisions for pregnant teenagers facing a medical emergency. The law requires notice to a parent, followed by a 48-hour waiting period, before a doctor can perform an abortion on a girl under the age of 18.
Where the justices differed from the Federal District Court in Concord, N.H., and the United States Court of Appeals for the First Circuit, in Boston, was on how to remedy the absence of a medical-emergency provision. The two lower courts had barred enforcement of the entire statute, even for the great majority of teenagers for whom the lack of an exception is not relevant.
The choice of this "most blunt remedy" was unjustified, Justice O'Connor said, when a "more finely drawn" remedy might be more consistent with the intent of the legislature, which passed the law in 2003.
Consequently, the Supreme Court vacated the appeals court's decision and ordered it to examine which option the legislature would have preferred: a statute with an emergency exception, or no enforceable parental-notice law. "We try not to nullify more of a legislature's work than is necessary," Justice O'Connor said. "The touchstone for any decision about remedy is legislative intent."
If the decision, Ayotte v. Planned Parenthood of Northern New England, No. 04-1144, turns out to be Justice O'Connor's last, it will be a fitting coda to a 25-year tenure in which she often played a pivotal role in the court's abortion jurisprudence.
Perhaps Chief Justice John G. Roberts Jr. had that in mind when he assigned her the opinion after the case was argued Nov. 30. It was evident from that argument that the justices were looking for a narrow way to decide the case and were setting aside, for the moment, whatever passion they bring to the abortion debate. Justice O'Connor's opinion embodied that collective judgment, whether under the guiding hand of the new chief justice or due to a confluence of individual responses.
However the New Hampshire decision was reached, "the decision preserves the status quo while the court is in transition," said Clarke D. Forsythe, senior attorney for Americans United for Life, a public interest law firm that litigates against abortion.
Mr. Forsythe filed a brief in the New Hampshire case on behalf of the sponsors of the New Hampshire law, the Parental Notification Prior to Abortion Act. In an interview, he said the answer to Justice O'Connor's question was "absolutely clear." Rather than have no parental-notice law at all, he said, the sponsors would accept an exception for medical emergencies, a choice he said they made clear by including a clause in the statute providing that if any application of the law was found to be invalid, "such invalidity shall not affect the provisions or applications" as to which there was no problem.
By including this language, known as a severability clause, the sponsors "practically anticipated" the court's decision, he said.
An opposite brief, on behalf of 153 New Hampshire legislators who opposed the parental-notice law, was filed in support of the plaintiffs, a doctor and three medical clinics. These legislators said the debate over the bill made clear that the sponsors wanted to test the Supreme Court's abortion precedents and "would have preferred to have no law rather than a law that contains a medical emergency exception in it."
Jennifer Dalven, a lawyer for the American Civil Liberties Union who argued the case for the plaintiffs in the Supreme Court, said in an interview that the sponsors "very clearly did not want a health exception" and predicted that the lower courts would once again bar enforcement of the entire statute.
"We're very happy that the court reaffirmed the need for a medical emergency exception," Ms. Dalven said, adding that the decision "tells politicians that they can't jeopardize women's health" when enacting abortion restrictions.
The Supreme Court for years has upheld state laws requiring parental involvement in a teenager's abortion decision, and 44 states now have such laws. The basic validity of these laws was not at issue. Nor, Justice O'Connor said, was the requirement that access to abortions "necessary, in appropriate medical judgment, for preservation of the life or health of the mother" may not be restricted.
Her opinion cited five precedents for that proposition, going back to Roe v. Wade in 1973. Notably absent from the list was the court's most recent abortion ruling, Stenberg v. Carhart, which in 2000 struck down Nebraska's ban on the procedure opponents call "partial birth abortion" in part because the law failed to provide a health exception. That decision provoked four vigorous dissents, and the price for the unanimity of the new opinion might have been the omission of the reference.
In spite of the Nebraska ruling, Congress passed the federal Partial-Birth Abortion Ban Act, now pending before the court in Gonzales v. Carhart, No. 05-380. The act does not include a medical exception, instead simply declaring that the procedure is never necessary to protect a woman's health. The case presents a direct challenge to the court's willingness to adhere to its precedent.