(Reuters Health) - U.S. women may be more likely to report that they belong to a sexual minority if they live in states that recognize same-sex relationships, according to a new study.

The finding is drawn from data on 69,790 participants in the Nurses’ Health Study II, which started in 1989 and included female registered nurses ages 25 to 42.

In 1995 and again in 2009, the women were asked about their sexual orientation. At the time of the first survey, no state recognized same-sex relationships. But by 2005 these relationships were recognized in 13 states and the District of Columbia.

In the 1995 survey, 68,608 participants (98 percent) reported being heterosexual, 536 (1 percent) reported being lesbian, and the remaining 1 percent either said they were bisexual (233 women) or none of the above (82 women), or they preferred not to answer (331 women).

By 2009, 2 percent of women had changed their answers; 116 more women reported being lesbians, 57 more reported being bisexual and 53 more reported being “none of the above,” the research team reports the American Journal of Public Health.

Women were more likely to switch their sexual orientation over time from heterosexual to lesbian, bisexual or other if their state recognized same-sex relationships, the authors found.

In fact, women who reported being heterosexual in 1995 were 30 percent more likely to report being a sexual minority in 2009 if they lived in a state that had some recognition of same-sex relationships in 2005, compared to women who lived in state with no recognition.

Women who changed their reported sexual orientation may have known at the time of the first survey that they were sexual minorities, but they may have made an error on the first report or chose not to disclose it, the researchers write. Or, women may have changed their sexual identity between 1995 and 2009.

While policies recognizing same-sex relationships may encourage people to accurately report their sexual orientation, the researchers say more research is needed to understand how other types of policies - like housing or employment discrimination - affect sexual orientation reports.

Gains in policies accepting or protecting the lesbian, gay, bisexual and transgender community in the U.S. may be in jeopardy under the new presidential administration, according to lead author Brittany Charlton, of Boston Children’s Hospital.

“Even if rights remain in place like those to marriage and military service, the new administration could deny equality to LGBT people in other ways,” she told Reuters Health in an email. “Employment and housing discrimination will continue without new legislation like the Equality Act and other advances could be halted that the Obama administration put in place.”

SOURCE: bit.ly/2gpfnPi American Journal of Public Health, online October 13, 2016.