SAN FRANCISCO -- In a ruling with coast-to-coast effect, a federal judge declared the Partial-Birth Abortion Ban Act unconstitutional yesterday, saying it infringes on a woman's right to choose.
US District Judge Phyllis Hamilton's ruling was in response to one of three lawsuits challenging the legislation President Bush signed last year.
She agreed with abortion rights activists that a woman's right to choose is paramount, and that it is therefore "irrelevant" whether a fetus suffers pain, as abortion foes contend. "The act poses an undue burden on a woman's right to choose an abortion," the judge wrote.
The ruling applies to the nation's 900 or so Planned Parenthood clinics and their doctors, who perform about half the 1.3 million abortions done each year in the United States.
In New England, the court's ruling has one main effect: it reinforces the legal protection already in place for doctors who provide abortions at Planned Parenthood clinics, said Erin Rowland, spokeswoman for the Planned Parenthood League of Massachusetts.
There are 47 Planned Parenthood health centers in the region, though only 13 provide abortions, and none offer abortions later than about 19 weeks into a woman's pregnancy, Rowland said. The ban's backers say it is meant to apply to abortions performed later than 18 weeks, but Planned Parenthood staff say it could apply to procedures as early as 15 weeks.
"The ruling means that all our doctors can continue to focus on providing the safest procedures for our patients without fearing prosecution under an extremely broad and vaguely worded ban," Rowland said.
Because Planned Parenthood's national federation was a plaintiff in the San Francisco case, its doctors in New England had already been covered by the court's preliminary decision to block enforcement of the ban until the case could be decided.
But yesterday's ruling further clarified which doctors could claim the protection of the Planned Parenthood umbrella.
It is now clear, Rowland said, that any doctor who accepts an abortion patient from Planned Parenthood is automatically covered; the protection also applies to an abortion provider who may, for example, work at a Planned Parenthood clinic one day a week and at a hospital two days a week, she said.
New England doctors who do not work with Planned Parenthood remain theoretically vulnerable to prosecution if they perform a later-term abortion that appears to fit the description in the "Partial Birth Abortion Act of 2003." The ban bars doctors from partially delivering a fetus and then killing it.
Some later abortions are performed in hospitals or private practices, but most are performed in clinics.
Federal judges in New York and Nebraska also heard challenges to the law earlier this year but have yet to rule. Those cases are expected to conclude within weeks. The outcomes, which may conflict with one another, are almost certain to be appealed to the Supreme Court.
Planned Parenthood lawyer Beth Parker welcomed the ruling, saying it sends a "strong message" to the Bush administration "that the government should not be intruding on very sensitive and private medical decisions."
In a statement, the Bush reelection campaign said: "Today's tragic ruling upholding partial birth abortion shows why America needs judges who will interpret the law and not legislate from the bench."
Justice Department spokeswoman Monica Goodling said the government "will continue to devote all resources necessary to defend this act of Congress, which President Bush has said 'will end an abhorrent practice and continue to build a culture of life in America.' "
The law, signed in November, represented the first substantial federal legislation limiting a woman's right to choose an abortion. Abortion rights activists said it ran counter to three decades of Supreme Court precedent.
In her ruling, the judge said it was "grossly misleading and inaccurate" to suggest the banned procedure verges on infanticide.
Representative Steve Chabot, Republican of Ohio, the chief sponsor of the House bill, said the banned abortion method "has no place in a civilized society," and predicted that the Supreme Court would decide the outcome.
The measure, which President Clinton had twice vetoed, was seen by abortion rights activists as a fundamental departure from the Supreme Court's 1973 precedent in Roe v. Wade. Abortion advocates said the law was the government's first step toward outlawing abortion.
Violating the law carries a two-year prison term.
Late last year, Hamilton, a Clinton appointee, and federal judges in New York and Lincoln, Neb., blocked the act from being enforced pending the outcome of the court challenges. They began hearing testimony March 29.
Doctors have construed the Supreme Court's decision in Roe. v. Wade to mean they can perform abortions usually until the 24th to 28th week after conception, or until the "point of viability," when a healthy fetus is thought to be able to survive outside the womb. Generally, abortions after the "point of viability" are performed only to preserve the mother's health.
Congressional sponsors said the ban would outlaw about 2,200 abortions a year.
Carey Goldberg of the Globe Staff contributed to this report.