In 1980, there were a million pregnancies to women under the age of 20. Forty percent of the girls who are now 14 years old will experience pregnancy at some point before they are 20 years old. One fifth of them will bear a child. Most of them will have had no intention of becoming pregnant.

These were among the more startling statistics given the House Select Committee on Children, Youth and Families Monday by Wendy Baldwin, chief demographer with the Center for Population Research of the National Institute of Child Health and Human Development. The picture she painted was of an age group that has increased in numbers and which has become sexually active at an earlier age with severe, long-lasting consequences primarily for the young women.

"It is not just the nine months prior to birth," said Baldwin. "If you look at these teen-agers 10 years later, you find that they are working more hours, have less prestigious jobs and less job satisfaction." Other studies show that teen-age parents have higher rates of marital instability, separation and divorce. Half of the families on welfare in 1975 were families that began when the mother was a teen-ager.

"The risk of pregnancy is really very high," she said, urging that sex education begin when youngsters first become interested and that it include courses that help them think through relationships. "I would love to see more done to inform the teen-agers about the risks, the cost-benefits of sexual activity," she said.

A number of studies, she said, show that the girls who are most likely to get pregnant are those who think they "don't have much opportunity, who won't be high achievers." Those who are less likely to get pregnant and give birth are the teen-agers who "want to go to college, who want to accomplish things. . . .Lack of self-esteem is one of those characteristics that goes with poor contraceptive planning."

Nancy Russo, the administrative officer for women's programs of the American Psychological Association, testified along similar lines recently before the House Subcommittee on Health and the Environment, which was also conducting hearings on teen-age pregnancy. "Females," she said, "are socialized to have low self-esteem, high need for approval and limited aspirations. Males are taught to denigrate females, to separate sex from affection and to exploit the opposite sex through 'conquest.' These are not characteristics that provide a foundation for responsible childbearing. . . .

"Access to contraceptive technology is not sufficient to ensure avoidance of unwanted pregnancy," she said. "Responsible childbearing also comes from the ability to say 'no' to males who would ask that a woman engage in sexual intercourse counter to her self-interest; it involves having goals and aspirations that make planning one's life meaningful; it involves developing a sense of independence and competence in women so they can participate equally in decisions about their sex lives."

In 1982, the federal government spent $125 million on family planning services through the Public Health Service Act alone, with more money spent through other programs. Despite growing expenditures of funds on family planning services, the problem of teen-age pregnancy has remained intractable. The number of conceptions, for example, rose 14 percent between 1974 and 1979, and the percentage of out-of-wedlock babies born to teen-agers tripled between 1960 and 1980. While it is impossible to imagine what the situation would be like had money not been spent on family-planning services, it seems clear that throwing money alone at the problem is not going to solve it.

The word "value" in connection with sex education courses has become a buzzword for controversial religious and moral standards which some have wanted to include in the courses. Both sides, however, ought to be able to see the merit of teaching young people about the high risks of pregnancy and the heavy price young women pay for early sexual activity. The research is available now to move that discussion from the religious consequences to the practical consequences. And it would also seem clear from the research that changes need to be made in the environment of young women.

Whether this means creating better educational and employment opportunities or seeing changes in social attitudes or both, there is a great deal to be said for having young women grow up knowing the value of valuing themselves.