The House of Delegates rejected a measure today that would have allowed school counselors and nurses to answer students' questions about pregnancy, venereal disease, drugs and alcohol in counties whose school boards now forbid such discussions.

A group now known as the Family Protection Lobby, formerly the Maryland Moral Majority, immediately claimed credit and declared the outcome a major victory for parental authority, but House leaders played down the action and the influence of the conservative right in the 82-to-49 vote.

A "minor bill" is what House Speaker Benjamin L. Cardin (D.-Baltimore) called it. "I don't think it's a measure of anything," said Majority Leader Donald B. Robertson (D-Montgomery), who voted for the bill, but with reservations because, he said, it was "terribly drafted."

The Family Protection Lobby chose to make the bill's defeat its first order of legislative business this year. After its forces trooped down to testify in committee, however, thier chances appeared slim. Panel members, angered over lobbying tactics that they termed harassment, quickly approved the bill for floor action.

"I don't think tht we're gonna win this one," said the group's executive director, Jim Wright, after he was sharply questioned by the angry committee. d

Today, however, Wright was savoring his victory. "From the beginning, I staked the reputation of the Family Protection Lobby on today's final vote," Wright said in a press release distributed right after the House vote. "As a test, I believe we passed with banners flying."

Some delegates contended, though, that the vote was influenced more by the decision of the state's Catholic bishops to oppose the measure. The Catholic leaders made their position known after a spokesmen had initially said they supported the bill as long as abortion was eliminated from the list of approved topics.

School boards in Prince George's Howard and Anne Arundel counties, as well as some principals in scattred districts across the state, now expressly forbid discussions of the proscribed subjects with students. The bill to reverse that policy passed the House last year 116-to-6 only to die in the Senate during the end-of-the-session crunch.

Today's debate was a predictable replay of earlier arguments. Del. Paula Hollinger (D.-Balitmore County), for five years a Catholic school nurse, said the measure was needed because, she said, parents often fail to provide guidance on such sensitive matters.

"Parental authority has been eroded enough by legislation, and I think this further decays the situation," stormed Del. Louis V. Cavallaro (D.-Baltimore).

There was an audible gasp as the votes were tallied. Wright said he thought the bill would lose, but only by three or four votes. As a contingency, he brought along two press releases, claiming victory in either case.

"Like a Boy Scout, you are always prepared," he said."You gotta turn everything to your advantage."

After the vote, Wright lost no time distributing his victory statement, thanking "our delegates for their wise, sober decision to reaffirm that parents, not the government, are ultimately responsible for the upbringing of our young."

The bill's cosponsor, Del. Kay G. Bienan (D-Prince George's) minimized its defeat, noting that nurses and guidance counselors are still free to discuss the forbidden subjects in most counties. In Anne Arundel, Howard and Prince George's, she said, students will "still be meeting their school counselors off school grounds after school" for guidance.

"It doesn't change anything," she said, adding: "I was surprised when the whole hoopla started because it wasn't worth it."