Shortly before the groups receiving grants learned their money would be cut early, a leader of an abstinence education advocacy organization, Valerie Huber, was named chief of staff to the health and human services assistant secretary who oversees adolescent health.
Mr. Vafiades said the funding cut-off was “not a decision made by one individual or based on anyone’s like or dislike of one approach.” Still, Ms. Huber, whom the department declined to make available for an interview, wrote in an opinion piece in March that the best message for young people was “to avoid the risks of teen sex, not merely reduce them.” She described the Obama administration’s approach as one “that has been alternatively named teen pregnancy prevention or so-called comprehensive sex education, but which typically normalizes teen sex.”
President Trump has elevated social conservatives, including Mr. Price, to influential roles. The administration is also seeking to defund Planned Parenthood, dilute the Affordable Care Act’s mandate that contraception be covered by insurance and cut budgets for other reproductive health programs, like Title X.
In what is widely considered a public health success story, teenage pregnancy rates have been declining nationally for 25 years. Factors include sex education in schools, movies and shows about teenage pregnancy, cultural shifts that have made it easier for parents to discuss the issue with their children and greater availability of birth control, especially long-acting contraceptives like implants and intrauterine devices.
But rates are still higher than in other industrialized countries, and there is little rigorous research about which approaches work. The Obama administration sought to gather better evidence by having 41 of the 102 projects funded from 2010 to 2014 independently evaluated. Most of those 41 projects were found to be no better than the sex education or behavior health programs already in place in the schools or communities where the projects were.
Only 12 of the 41 were found to have changed sex-related behavior. Brian Goesling, a senior researcher at Mathematica Policy Research, which evaluated some projects, said the Health and Human Services Department commissioned the research to see what worked and to then replace the projects that did not. One lesson was that projects that were effective in one community might fail elsewhere because of different teachers, different teenagers and “a different context,” he said.
The clinical therapists Jo McClain, left, and Katrina Upton leading students through a pregnancy prevention curriculum at New Foundations, a group home for children in Anderson.CreditTravis Dove for The New York Times
Sometimes, positive effects seen at three or six months evaporated by 12 months. And some projects did not measure pregnancy rates, but “self-reported sexual activity, and it’s not clear if that’s reliable,” said Jon Baron, vice president of evidence-based policy at the Laura and John Arnold Foundation, a nonpartisan foundation that has reviewed the evaluations.
Notably, the most successful program helped teenage mothers in Columbus, Ohio, avoid another pregnancy, partly by directing them toward long-acting contraceptives, Mr. Baron said.
Still, he said, the success rates of the evaluated projects were similar to those of clinical trials in medicine, so cutting funding for pregnancy prevention is like “cutting medical research because the vast majority of approaches, interventions and treatments that are tried are proven not to work.”
Abstinence-only programs have often failed to change teenage sexual behavior. A 2007 study of four such federally funded programs, for example, found “not even a hint of an effect on sexual activity, pregnancy or anything,” Mr. Baron said.
Still, the Obama administration’s menu of “evidence-based programs”includes three abstinence programs.
One of the current federal grants, $2.2 million a year, goes to the South Carolina Campaign to Prevent Teen Pregnancy, which uses it for programs in schools and group homes, as well as the clinic for teenagers in Anderson that emphasizes long-acting contraception. The organization’s project manager, Beth DeHart, said it also received federal permission to supply condoms in nontraditional places, including a bowling alley, nail salons and barbershops.
Project leaders consider the programs beneficial in South Carolina, where births by teenagers dropped to 3,740 in 2016 from 6,954 in 2010. But they acknowledged not everything has worked.
An urban-focused middle school program of computerized and classroom lessons that seemed promising in Houston mostly made no difference in rural South Carolina, but had one troubling result: Students who were sexually inexperienced before seventh grade were more likely to have had sex by late ninth grade.
“We learned that is not the right curriculum for South Carolina,” said Beth De Santis, the chief executive of the South Carolina Campaign to Prevent Teen Pregnancy. “Preventing teen pregnancy is very complex. There’s not one silver bullet.”
Ms. DeHart said their organization told schools “please do not use this program anymore with the young people.”
Now, Anderson County’s schools use two other programs. Mr. Baron said each showed some preliminary positive effects, one in Philadelphia and one in Northern California.
Interviewed at United Way of Anderson County, Latavia, who lives in a housing project, said her programs’ instructors discussed saying no to sex, and “We learned how to put a condom on a penis.”
At New Foundations, a group home for youths who come from foster care or the justice system, seven girls attended a recent session on pregnancy prevention. Four were born to teenage mothers, said Katrina Upton, a registered nurse and clinical therapist, and Jo McClain, a clinical therapist. Asked what was the safest behavior, a girl said, “Not doing it,” and was surprised to learn that “abstinence” meant the same thing.
Afterward, Francis, 17, who is at the group home because of a drug-related arrest and asked that only her middle name be used to protect her privacy, said she would talk with her boyfriend about “not having sex so much.” She will also ask him to get tested for sexually transmitted diseases “in case he has been doing stuff, like, behind my back,” she said, and “if we do have sex again.”