The ruling struck down the 1987 law, which has never been enforced, as unconstitutional.

"No one would doubt the value to a pregnant minor of wise and caring parental guidance and support as she confronts a decision that will affect the rest of her life, assuming such support is available and the minor is willing to seek it," the court's written ruling said.

"The statute at issue however ... has its most significant impact in those instances in which a pregnant minor is too frightened or too embarrassed to disclose her condition to a parent (or to a court)," it said.

Both a trial court and a state court of appeal had found the law to be unconstitutional, but the state Supreme Court ruled last year on a 4-3 decision that it was constitutional.

However, after two new judges were appointed, the state's highest court granted a request by opponents of the law to review the case again, this time reaching a different conclusion.

Margaret Crosby, an ACLU of Northern California lawyer involved in the case, praised the ruling, saying it reaffirmed "California's powerful protections for reproductive decisions."

"In the finest tradition of judicial review," Crosby told Reuter, the court "fulfills its obligation to safeguard fundamental rights."