Planned Parenthood vowed yesterday to sue the government, take its case to Congress, and even give up federal funds in its fight against a proposed government regulation to alert parents when teen-agers get birth control prescriptions.

Faye Wattleton, president of the Planned Parenthood Federation of America, said that her group will "never retreat" from its longstanding policy of providing confidential services to teen-agers and others who seek family planning services.

Planned Parenthood is the largest private family planning agency nationwide, with a $150 million annual budget. Wattleton said that 116 of its 188 affiliates around the country receive federal funds, including about $30 million from the Department of Health and Human Services' family planning program.

The department has published a federal notice saying that agencies that take these funds must notify the parents of teen-agers under 18 within 10 days after birth control prescriptions are provided. HHS is accepting public comments until April 23 and then will proceed with a final rule.

Wattleton said that if HHS Secretary Richard S. Schweiker goes ahead and invokes the rule, as is generally expected, Planned Parenthood will challenge its legality in the courts. She added that opponents of the regulation will also "look to Congress for additional support."

But she acknowledged that if her organization is not successful, it eventually "may mean the decision to withdraw from the receipt of federal funds" rather than breach the confidentiality pledge.

"Planned Parenthood has a long and distinguished history of providing confidential services to millions of Americans, regardless of age, race, sex, financial circumstances or disability. We will not abridge that policy," Wattleton said at a news conference.

Planned Parenthood affiliates serve more than 2.5 million people annually, including 175,000 teens under 18 who would be affected by the regulation.

Staff lawyer Ellen Kramer said that the Planned Parenthood suit would challenge the proposed regulation as being unconstitutional as well as violating the intent of the congressionally passed family planning law and previous department policies.

An HHS spokesman responded that "we're confident the courts would uphold our position." He said that over 20,000 groups and individuals have already commented on the proposal but that the government has not yet tallied up the numbers pro and con.

Wattleton said that early estimates suggest the response is largely negative. She and others argue that the proposal would keep some teen-agers from seeking help because they don't want their parents to find out and more pregnancies would be the result.

"While we totally support the concept of encouraging communication between parents and their teens, we categorically reject the notion that such involvement can be mandated by government fiat," she said.

Schweiker argues, however, that the current policy of confidentiality builds a wall between parent and child. Conservative groups have expressed concern that the proposal does not go far enough and should instead require parental consent for birth control services.

The HHS proposal says that parents have a right to be informed when their children receive prescription products, such as the birth control pill, that may pose a potential health risk