The US Supreme Court has called for a review of a lower court decision to overturn a law demanding that a minor's parents be informed of an abortion.
The US Supreme Court is going through a period of change
Retiring Justice Sandra Day O'Connor said an appeals court was "wrong to invalidate the law wholesale".
She argued that it was not always necessary or justified to reject the New Hampshire law's demands during medical emergencies.
Abortion is one of the most contentious issues before the Supreme Court.
Under laws introduced in New Hampshire in 2003, doctors must provide 48 hours notice to parents of girls under 18 who want an abortion.
The only time a pregnant minor can have an abortion without parental knowledge is if their life is in danger.
A reproductive health care group, Planned Parenthood of Northern New England, decided to fight the law, arguing that it placed an undue burden on pregnant girls and that a pregnant minor should be able to seek an abortion, without notifying a parent, in the event of a medical emergency that is not life-threatening,.
''In an emergency, a woman needs to go to the hospital not a courthouse,'' a lawyer for Planned Parenthood wrote in a statement to the Supreme Court.
A federal judge and a US appeals court in New Hampshire subsequently struck down the legislation, declaring it unconstitutional.
However, in this latest ruling the Supreme Court said it was wrong for the law to have been totally quashed, and called for further review.
In 19 states, minors who want an abortion must inform at least one parent, while 24 other states require parental approval before a procedure.
In the 10-page court opinion, retiring Justice Sandra Day O'Connor wrote that invalidating the whole law was not always necessary or justified in cases involving medical emergencies.
The latest case does not involve a challenge to the landmark 1973 Roe v Wade case, which formalised the nationwide right to abortion in the US.
However, Supreme Court rulings on abortion are closely scrutinised to see if they reflect a shift away from that landmark case.
That monitoring has increased in recent weeks as Ms O'Connor is due to retire from the Supreme Court and be replaced, possibly by President Bush's nominee Samuel Alito.
Pro-choice campaigners are concerned that the conservative Mr Alito could tip the balance of the court, possibly even to the point where Roe v Wade could be overruled.