BOSTON -- Supporters of a comprehensive sex education bill say momentum is building behind their years-long push, with a majority of state lawmakers lined up behind the legislation.

The bill, dubbed the Healthy Youth Act, would require that school districts offering sexual health education provide medically accurate and age-appropriate information, including LGBTQ-inclusive material and discussion of consent and healthy relationships. It would allow parents and guardians to opt their kids out and to review instruction materials before the course begins, if they request to do so.

The Senate has passed versions of the bill in each of the last two sessions, but House leadership did not bring it to the floor for a vote in either term.

The bill's Senate sponsor, Assistant Majority Leader Sal DiDomenico, said the bill was "common sense for our kids to make good decisions" and said there's "strong support" for it in his branch.

"We fully expect this to happen as soon as the committee reports it out," he told the News Service Monday. "We should be taking this up very quickly on the Senate side."

As the Education Committee held a hearing on the bill, House Speaker Robert DeLeo told reporters that he was "anxiously" awaiting "what the committee's final decision may be with it," noting that some changes have been made to the language over the years.

"But it's something, obviously, that I think will be on our radar to take a look at," the Winthrop Democrat said.

More than 70 House lawmakers had co-sponsored last session's bill. This year, 97 representatives have signed on to the version of the bill filed by Reps. Paul Brodeur and James O'Day (H 410), including House Ways and Means Chair Aaron Michlewitz and Education Committee Co-Chair Alice Peisch.

The House bill has a total of 109 cosponsors from both branches, and DiDomenico's bill (S 263) has 44.

"I think this is a bill whose time, absolutely, has come," O'Day told the Education Committee.

A social worker for 25 years before he joined the Legislature, O'Day said he'd been in dozens of homes over the years where he spoke to pregnant teenagers who did not know how they'd gotten pregnant.

Hannah Tello, a community health researcher in Lowell, said some of the anonymously asked questions she's fielded from college students at a weekly drop-in sex education course have included how many times is it safe to reuse a condom, and whether you develop an immunity after getting a sexually transmitted disease the first time.

"I've seen firsthand that young adults are moving into the world unprepared to make informed health decisions, not because they don't want to, but because we, the adults in this room, have failed to provide them with the information and resources necessary to do so," she said.

The bill does not mandate schools teach sex education. It sets a list of required elements for schools that do offer it, including instruction on human anatomy; the benefits of abstinence and delayed sexual activity; preventing sexually transmitted infections; relationship and communication skills, and information about gender identity and sexual orientation.

Opponents of the bill object to the state spelling out what sex education curriculum should look like.

The Massachusetts Family Institute in a press release flagged language in the bill that calls for abortion to be discussed as one of "the options for pregnancy," along with parenting and adoption, and for "affirmative recognition that people have different sexual orientations, gender identities, and gender expressions, and information about resources that offer support for lesbian, gay, bisexual, transgender, queer and questioning students."

"These bills take control over sex education out of the hands of local school districts and give it to state bureaucrats," Massachusetts Family Institute President Andrew Beckwith said in a statement. "Parents, teachers and administrators should be able to decide for themselves what is best for the students in their own community. Why is the legislature trying to take that right away?"

Representatives from the Boston Area Rape Crisis Center, the Massachusetts LGBTQ Youth Coalition, Fenway Health and Jane Doe. Inc, a Massachusetts coalition against sexual assault and domestic violence, testified in support of the bill, as did a handful of students who told lawmakers about their own sex education experiences.

Anna Stanforth, who graduated last week from Pioneer Valley Chinese Immersion Charter School in Amherst, said her first sex education class came in the ninth grade, when some students were already sexually active. It was taught by a gym teacher and did not cover how to prevent either pregnancy or contracting sexually transmitted infections, she said.

Stanforth said she received "thorough" sex education through her Unitarian church, including information on healthy relationships, and eventually other classmates began coming to her with their questions, including one girl who worried she was pregnant. Stanforth and a friend also created a workshop on consent to help their peers.

"It shouldn't be students' responsibility to teach other students," she said. "It's a matter of safety to educate young people on these topics so they don't end up pregnant, or with an STI, or sexually assaulting another student."