What constitutes sex education and the grade in which it's taught varies greatly in America, and this year is shaping up to set a record for legislative proposals that are mostly aimed at restricting the teaching of the subject in schools.

Ali Rogin has more on the increasingly complicated nature of sex education.

ALI ROGIN: The Centers for Disease Control defines quality sexual education as medically accurate developmentally appropriate culturally relevant content that promotes healthy development but only three states require comprehensive education to be taught in all schools.

17 states provide abstinence only sex education.

And so far this year at least 135 bills pertaining to sexual education have been introduced, or are in place nationally, a majority of which would place restrictions on sexual education in public schools.

That's according to an analysis by the nonprofit organization, Sexuality Information and Education Council of the United States.

Sara Flowers is Vice President of Education at Planned Parenthood Federation of America, a nonprofit organization that provides reproductive and sexual health care and sexual education in the United States and globally.

Dr.

Flowers, thank you so much for being here.

First of all, when we think about comprehensive sex education, what does that look like?

SARA C. FLOWERS, Planned Parenthood Federation of America: Comprehensive sex education means teaching a wide variety of topics in grades K through 12, including topics like consent, understanding what boundaries are and how to decide where your personal boundaries are self-esteem, anti-bullying, healthy relationships, how to stay safe online.

And of course, the things that most people usually think of when they think of sex education, which is like puberty, contraception, and STI prevention.

There's also a wealth of research that shows that kids who get this sort of comprehensive sex education and start in elementary school build on those skills through middle and high school are more likely to foster healthy relationships, have better social emotional skills, respect sexual and gender diversity, and prevent unintended pregnancy and STI transmission when they do become sexually active.

That's education works like building blocks.

So it's incredibly important to start these conversations at home and in school, and to have them early.

And often.

What I mean by building blocks is this.

When we teach math, we start with the basics.

Kids learn to count zero, one, two, three.

Eventually, we move into addition and subtraction.

We don't start with calculus.

So for topic like consent, if you're a small child, you understand that you don't want someone to take your truck without asking.

An elementary school consent covers topics like how to ask before taking a snack from someone else's lunchbox, or how to respect another person's decision not to want to be hugged.

In middle school, learning about consent includes talking about peer pressure, learning assertive communication skills, thinking about your own boundaries, and learning to respect the boundaries of others.

In high school, we talk about consent during sex, we talk about thinking about what we ourselves would like getting clear on our own wants and dislikes and being a good listener making space for a partner to communicate their wants and needs, and being able to say no, and also to respect someone else's.

Now, it also talks about how to continually check in to make sure that everyone feels safe as the relationship evolves.

ALI ROGIN: There's a wide variety of sexual education curricula that really varies based on the state.

And as I mentioned, 17 of them are abstinence only.

But what is behind the varied nature of sexual education state by state?

And what is the effect of having such different regimens available, depending on where you live?

SARA C. FLOWERS: It's really important for parents to understand that in the U.S., there is no law or national program that dictates if sex education is going to be taught in schools and how sex education was going to be taught in schools.

We have a patchwork of sex education laws and policies across the country.

So instead, decisions about sex education are left up to states and school districts.

This means that the quality of sex education including the curriculum who is teaching and whether or not it's medically accurate, as well as whether or not you receive it at all, all of that depends on where you live, and who makes decisions about sex education in your area or school or school districts.

ALI ROGIN: There is a effort happening on the federal level in Congress to pass a bill that would establish grants for comprehensive sexual education.

Is that what you see as a necessary step here?

And how would that potentially change things?

SARA C. FLOWERS: It would absolutely be a necessary step if all young people got the sex education that they deserve, sex education that is comprehensive, inclusive, culturally congruent and age appropriate, then we, as a society have the potential to raise a generation of young people who not only know how to love and take care of their own bodies, but we'd work towards a world where all people including people who are in power making decisions for others.

Everyone would understand the importance of things like respecting bodily autonomy respecting people's differences and the basic understanding of how pregnancy happens and how it works.

ALI ROGIN: Some of these bills that we mentioned would ban discussions around gender identity and sexual orientation.

Some would remove instruction on contraception, and emphasize abstinence.

Some lawmakers who are in favor of these bills would say these are to protect the age appropriate nature of the sex education content that's in the classrooms.

What do you see as the impact of those steps that are limiting the topics that can be discussed?

SARA C. FLOWERS: It's really important to understand that sex education is under attack.

And it is under attack by the same groups that are trying to ban books stop trans youth from being able to play sports or use the bathroom that they need, and the same groups that are trying to ban teaching accurate history.

The bands are all connected, and which tells us that these groups are actually working to exert power and control our kids.

They are not trying to keep kids safe and healthy.

Parents can do something about these bands.

You can start by finding out what's currently taught in your kids school.

And if it's not sufficient, ask for better.

Now we did mention that there are people who live in states and communities where sex education is not permitted to be taught in schools.

In those areas, parents and families can reach out to their local Planned Parenthood to find out if their education department can connect you with sex education programs, sex education can happen on after school programs and on weekends.

It doesn't have to happen in schools.

ALI ROGIN: Sara Flowers, Vice President of Education at Planned Parenthood Federation of America, thank you so much for being here.

SARA C. FLOWERS: Thank you so much for having me.