A plan to open the District's first health and birth control clinic in a public high school was strongly criticized by about 15 District residents last night during a hearing attended by about 50 people at Anacostia High School.

The proposed clinic, where students would be able to obtain birth control pills and other contraceptives without parental approval, was opposed by parents and religious leaders who said they were afraid the clinic would "condone" and "encourage" teen-age promiscuity and keep parents "in the dark" concerning their children's health.

Of those attending, fewer than 10 said they were parents of students who attend Anacostia, the Southeast school where the first clinic would open in July if the plan is approved. Other clinics would open at District schools in the following months.

Two persons praised the proposal, sponsored by Planned Parenthood of Metropolitan Washington, including a 19-year-old mother who said she became pregnant two years ago while a student in a Maryland high school. She now works for Planned Parenthood.

Among the opponents was the Rev. Willie Wilson, an outspoken religious leader and pastor of Union Temple Baptist Church in Southeast, who said, "Overall, health care is positive, but providing contraceptives of any sort . . . condones what we know to be the spirit of the times, which is one of free sex. Contraceptives will not solve the problem. It may even expand the problem."

Sharon Robinson, special projects coordinator for Planned Parenthood, tried to quell such fears by urging people to "remember that we're talking about a full, comprehensive health clinic. We don't have to have contraceptives in the clinic . . . . We don't perform abortions at school-based clinics, but we can refer students to an agency where they can get abortion [consultation]."

She said that, in accord with city and federal law, after a parent gives the clinic permission to see a child, health specialists would not have to disclose information to parents about family-planning services or treatment the student might receive for sexually transmitted diseases.

Last night's public hearing was the first in a planned series of meetings to discuss the controversial proposal, which has been recommended to Mayor Marion Barry and D.C. School Board members.

Concerns similar to those expressed last night have been voiced in hearings in other cities where Planned Parenthood representatives have initiated proposals for school-based clinics. About 35 schools across the country have approved the clinics.

"I would vote against this proposal if you're not planning to let parents know what's really going on with their children," said Florence Powell, president of the Anacostia Parent Teacher Association, who was joined on the auditorium stage by 10 school and city officials. Among the officials was Dr. Joyce Ladner, who was head of the mayor's blue ribbon panel on teen-age pregnancy last year.

"One out of every five live births in the District is to unwed teen-age girls," Ladner told the audience. "We found that a lot of families do need help with their teen-agers. School based-clinics can be very helpful. They are not intended to prevent pregnancy, but to improve the overall quality of life. It's painful to see 12- to 15-year-old children having children."