Washington ? Teenagers at high schools where condoms were available were no more likely to have sex than other teens, a study says.

The study published Wednesday backs earlier research on the programs developed in the 1990s to stem the spread of HIV and reduce teen pregnancy. It says that students in high schools with condom programs were more likely to use condoms, while students in other high schools were more likely to use other forms of birth control.

Overall, there was no difference in pregnancy rates. The study could not determine whether there was an increase in sexually transmitted diseases.

Many conservatives have staunchly opposed condom programs, saying they send the wrong message and encourage and enable teens to have sex before marriage.

Researchers writing in the American Journal of Public Health examined high schools in Massachusetts, where the state Department of Education encouraged schools to develop condom programs. In most cases, the condoms were available from the school nurse or from other personnel such as a gym teacher.

The study took a sample of all high schools, comparing students at nine schools that made condoms available with those at 50 schools that did not. The data came from a 1995 survey of students’ sexual behavior.

They found students in schools with condom programs were slightly less likely to report having had sexual intercourse than those at other schools. Specifically, 49 percent of students at non-condom schools reported having ever had sex, compared with 42 percent of those at schools with condoms available.

“The concerns of the small minority of parents who oppose providing condoms or related instruction in schools were not substantiated,” wrote lead author Susan M. Blake and her colleagues at the George Washington University School of Public Health and Health Services.

The study did not compare teenage sexual behavior before and after condom programs were instituted, researchers note, so the study does not prove that the program changed anyone’s behavior.

Opponents of the condom programs seized on that weakness in the study.

“If you look behind the headlines, you’ll see this study is much ado about nothing,” said a statement from Ken Connor, president of the Family Research Council, a conservative group that focuses on social issues.

Connor said making condoms available “sends kids the wrong message and gives them a false sense of security that they will be protected.” While condoms protect against transmission of HIV, he noted that some diseases can be transmitted during sex even with a condom.