Fewer teen-agers would become pregnant if there were better sex-education programs in the schools, greater parent initiative in discussing sex and increased availability of over-the-counter contraceptives, according to a study released yesterday, based on the recommendations of District teens.

"The United States leads most developed countries in its proportions of teen-age pregnancies, and the District has the highest pregnancy rate in the country," psychologist Henry David told a group of more than 100 civic leaders and sex-education specialists at a workshop on teen pregnancy at the National Baptist Memorial Church.

"Adults must learn to accept the fact that teen-agers engage in premarital sexual behavior with or without their sanction," said David, director of the Transnational Family Research Institute, co-sponsor of the study with Planned Parenthood of Metropolitan Washington.

"It is our responsibility to reach out to adolescents, to help them be responsible for their sexual behavior and to serve them in accordance with their needs."

The study utilized the advice of about 60 "peer counselors" at six inner-city high schools.

In a program sponsored by Planned Parenthood, peer counselors study topics such as reproductive anatomy, contraception, pregnancy, childbirth, abortion, venereal disease, sex roles, dedision-making and communication skills, to help them translate information from adult experts into language their classmates can understand.

"Despite the extensive efforts of family-planning clinics to provide sexually active teen-agers with . . . contraceptives, and although teen-agers are coming to such clinics in ever increasing numbers, the proportion of young teen-agers confronted with problem pregnancies continues to climb," notes the study, which was funded by the National Institute of Child Health and Human Development's Center for Population Research.

"It is time to look at teen-agers' needs through teen-age eyes and try to meet their expectations."

The peer counselors' major recommendations:

Improving standard school sex-education programs by placing more emphasis on women's needs, assertiveness-training and communication problems with males, particularly concerning basic contraception information.

Most school sex-education programs present little more than "plumbing and biological facts," says the study. "It is curious that at a time when adolescents can obtain contraceptives and abortions without parental permission or notification in many cities and towns, parental consent is still required to participate in so-called sex-education classes in most American public schools."

Specifically, the peer counselors suggest "teaching girls about the risks to themselves if they become pregnant before they are ready to be mothers, and teaching both boys and girls in biology and health classes how birthcontrol methods actually work to prevent pregnancy."

They also recommend assertiveness-training classes to help both male and female teen-agers deal with peer pressure.

Greater parent initiative in talking about sex and pregnancy with their children .

"Some parents feel threathened by their children's apparent sophistication on sexual issues and allow erroneous information about contraception to persist," says the report.

"New community approaches must be explored and fresh initiatives supported if the adolescent cry for parental help and understanding is to be accommodated."

For example, peer counselors suggest rap groups where teen-agers could discuss their own problems and questions about sex with the parents of other teen-agers, not their own mothers and fathers. Another rap session would allow parents to discuss their concerns about teen-age sexuality with other teens, not their own.

Increased availability and attractiveness of over-the-counter contraceptives .

"The experience of peer counselors confirms that present clinics with their medical aura are not ideally suited to the interest of adolescents . . . who are often fearful of pelvic examinations, blood tests and medical authority figures."

The report also recommends gearing specifically to teens radio and television advertising, marketing and store display of over-the-counter contraceptives.

"For far too long society has been reluctant to reach out to adolescents and initiate contraceptives instruction for young people before sexual debut. Usually, this lack of action has been justified by the mistaken belief that societal sanction encourages premarital activity.

"Statistics clearly indicate that such thinking has been 'overtaken by events' and is self-defeating as we enter the 1980s."