Students who participated in abstinence-only sexual education programs were just as likely to have sex later as those who did not, according to a federally mandated study.

The results of this study could have serious implications because Congress is considering renewing the block grant program for abstinence education -- known as Title V -- this summer. The federal government has authorized up to $50 million annually for the program, according to MSNBC. Critics of the program have repeatedly said that abstinence-until-marriage programs do not work.

The study, conducted by the nonpartisan Mathematica Policy Research, found that students who attended one of four abstinence classes reviewed reported having similar numbers of sexual partners as those who did not attend the classes. Also, the students in the abstinence-only classes first had sex at about the same age as those in the control group -- 14.9 years.

Simon Holowatz, community health educator at University Health Services, said he agreed with the results of the study.

"Abstinence-only education is not useful at all," he said. "There's no evidence at all that abstinence education works."

Holowatz said at best, abstinence-only education might decrease the age at which teenagers first have sex, but at worst, can lead to a false sense of security about sexual risks.

"There's nothing wrong with saying 'I'm going to wait' -- that's great. But it shouldn't be the only form of education," he said. "We need to educate [teenagers] so that when they do have sex, they can be safer."

Mathematica's study looked at youths in four different areas -- Miami, Milwaukee, Powhatan, Va., and Clarksdale, Miss. -- who participated in abstinence-only education programs, as well as students from those areas who did not participate. The students who participated in abstinence education did so for one to three years, beginning at about age 11 or 12. Mathematica found that about half of each group reported that they remained abstinent.

Moira Gaul, director of Women's and Reproductive Health for the Family Research Council, said the results of the study are not representative of the totality of abstinence-education programs.

The four programs evaluated in the study have been revised and improved, and their methodology has been strengthened, Gaul said.

"While the results of these four programs evaluated were somewhat disappointing, they by no means prove abstinence education ineffective," she said.

Susan Rose, a professor of sociology at Dickinson College, said she thinks sexual education in the U.S. will change. "More and more states are resisting federal funding for abstinence-only education ... the data is just becoming so clear that ultimately I think things will change," she said. "Without being naïve, I have hope."

Gaul said the Family Research Council will continue to push for more federal funding toward abstinence programs.

"The best preventive method is abstinence until marriage for multiple health outcomes," she said.

Holowatz said the current sexual education policy is based on politics, not education.

"People need comprehensive sexual education, which includes information about resources available, what kinds of risks are involved with sex, and addresses students' current and future needs," he said. "We're not going out and saying 'have sex,' we're just saying if you are going to have sex, here's some stuff you should know."