For months, Joyce Ladner has been listening to District teen-agers talk about sex, pregnancy and growing up in a confusion of contrasting morals.

Much of what she has heard has been disturbing. But Ladner, who heads the Mayor's Blue Ribbon Panel on Teen-age Pregnancy Prevention, says she is not discouraged as the panel's series of controversial public hearings held in D.C. public schools nears the midway point.

"I want to know what's on their minds," said Ladner, a professor of social work at Howard University. "If we can know that, we can intervene."

Recently, Ladner and eight panel members gathered in the auditorium of Cardozo High School and heard, among others, a teen-age father mumbling about responsibilities, an 18-year-old mother urging "practice now" if one plans to be a teen-aged mother, and a young immigrant mother from Guatemala tearfully telling her story of teen-age marriage, pregnancy, abuse and abandonment by age 21.

The hearings, which have brought new attention to what local health officials say is an epidemic of babies having babies, have been said by some to be too sensitive for most teen-agers. Responding to the criticism, Superintendent Floretta D. McKenzie recently said the remaining pregnancy hearings will be held only in high schools.

But Ladner, who began pushing for the hearings soon after Mayor Marion Barry created the panel in May, says she remains determined to hear what young people have to say, and she took issue with excluding junior high school students.

"I can't see how we can say young people in junior highs shouldn't be able to talk about this when they are exposed to other sexual influences in society," Ladner said.

The public fact-finding, her panel colleagues say, is part of Ladner's commitment to see the human faces behind the statistics.

"She is really interested in human suffering and trying to alleviate it in some way," said Joseph Citro, program director of the Family Place, a support group for pregnant women and mothers with young children. "She really tries to reach out in her own humanity and touch the lives of other people."

Last month, an unwed 18-year-old mother of two stood before 300 of her former classmates at Fletcher Johnson Community School in Southeast Washington. In a tiny voice made even smaller by her nervousness, Joannie Marshall said that "having a baby when you are a baby is hard."

Ladner looked up from her notes, smiled, and asked Marshall a simple question: "How can we help the young person to say no?" Marshall searched for an answer.

"She didn't make me feel low," Marshall said later. "It's hard, not easy to talk like that. But I was telling her how I felt."

A native of Palmers Crossing, a small town in rural Mississippi, Ladner grew up during the most active days of the civil-rights movement. It was an experience, she says, that hardened her resolve to bring about social change and further fueled her need to explore -- up close -- the fabric of society, particularly the complex tapestry of black society.

That need drew her to projects such as a study of life in a St. Louis housing project, an examination of women's role in post-colonial Africa, and now her look at the District's teen-age pregnancy problem.

As a research assistant working toward her doctorate at Washington University in St. Louis, Ladner, then 20, posed as a resident of a public housing project. She says she had a pelvic examination at a public health clinic to try to understand why women in the project tended not to go to the clinic for contraceptives.

She got her answer. "It was dehumanizing because the doctors treated me like I was nothing," she recalled, " . . . as an nonentity."

In 1968, Ladner turned her investigation of life in the Pruitt-Igoe housing project into her doctoral dissertation. Three years later she developed that work into her first book, "Tomorrow's Tomorrow," a study of 100 black girls growing into womanhood.

Today, Ladner, 41, a divorced mother of a young son, says she cannot see the faces of a generation that is producing 30-year-old grandmothers and remain the impassionate scientist. She says she feels the pain, too.

"I see the children," she said. "Some people get tears when they see starving children in Ethiopia and Somalia. I get the same kind of feeling when I see it in less graphic, less stark forms.

"It's a slow death here," Ladner said. "I see the trends."

In Washington, about 20 percent of the live births last year were to teen-age mothers, she says, adding that these children usually face higher health risks and lower educational opportunities.

"I think that mostly what we are dealing with is the problem of adolescence," she said. "Kids don't plan for most things . . . . They are growing up, and I don't know why we as adults expect them to be more responsible in the areas of sex than they are in other areas."

"All society tells them is that if you feel it, act on it," she said. "But we can make a difference.