Wisconsin doesn't require public school districts to teach human growth and development — often referred to as sex education — but school boards can choose to provide instruction.

Because it's left up to each district, what's taught could be different in each of the state's 421 public school districts. The curriculum is up to each district, according to the state Department of Public Instruction.

But there are some guidelines. If a school district does provide instruction, there are recommendations for what is, and isn't, required.

Here's a closer look at those recommendations:

What should the curriculum include, if a district chooses to teach it?

The state recommends providing medically accurate information on the following, when age appropriate:

• Importance of communication about sexuality between a student and their parents or guardians.

• Reproductive and sexual anatomy and physiology.

• Benefits and reasons for abstaining from sexual activity, stressing abstinence as the only reliable way to prevent pregnancy and sexually transmitted infections (STIs).

• Healthy life skills, including setting goals, making decisions and managing stress.

• How drugs and alcohol use affect responsible decision making.

• The effect of media and peers on thoughts, feelings and behaviors related to sexuality.

• Adoption resources, prenatal care and postnatal supports.

• Nature and treatment of STIs.

The state doesn't specify which ages these topics should be taught at, but it defines "age appropriate" as suitable "based on their developing cognitive and emotional capacity and consistent with adolescent development and community standards." It also says instruction can be provided from kindergarten through grade 12.

The statute also recommends teaching about healthy relationships, resources for survivors of sexual abuse or assault, and the positive connection between parenting and marriage.

There are no explicit recommendations to teach about other forms of contraception, consent or abortion.

OK, but are there any required topics for districts that choose to teach human growth and development?

If a district chooses to teach human growth and development and it teaches any of the recommended topics in the bulleted list above, then there are some requirements.

Districts that check both of those boxes would then need to teach, in the same year:

• Abstinence as the preferred choice for unmarried students.

• Abstinence before marriage as the only reliable way to prevent pregnancy, STIs, HIV and AIDS.

• Parental responsibility and the socioeconomic benefit of marriage for adults and their children.

• Pregnancy, prenatal development and childbirth.

• Criminal penalties for engaging in sexual activities with a child.

• Sex offender registration.

• Medically accurate information about HPV, HIV and AIDS.

• Process allowing a parent of a newborn child to relinquish custody to a law enforcement officer, emergency medical services practitioner or hospital staff member.

Does Wisconsin allow students to opt out of sex education?

Yes. Individual students can be exempt if their parent or guardian submits a written request to the school or teacher.

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Are Wisconsin parents allowed to review sex education curriculum and materials?

Under state statute, districts that teach human growth and development should provide parents with an outline of the curriculum and information on how to opt out annually. Instructional material should also be available for parents to review upon request.

Some districts, like the Appleton Area School District, post curriculum online for anyone to access.

What do experts say are best practices for teaching sex education?

Sex ed curriculum in the United States falls into three buckets: abstinence until marriage, abstinence-plus and comprehensive, according to Nancy Kendall, a professor of educational policy studies at the University of Wisconsin-Madison.

“None of the sex education approaches are wildly successful,” she said.

Determining effectiveness depends on the goal of teaching the material, she said. If your goal is to teach that sex is dangerous, only allowed within marriage and that contraceptives are fallible, then an abstinence-until-marriage approach could achieve that.

If the goal is more focused on increasing the use of contraceptives or reducing STI transmission, Kendall said, then the most effective choice is a comprehensive curriculum — which could include both of those topics, as well as relationships, gender roles, pregnancy, sexuality and more.

Abstinence-plus approaches similarly talk about more topics than just abstinence, but still emphasize it as the preferred choice above condoms, other birth control and other strategies.

Regardless of the approach, the material should be medically accurate, unbiased and rooted in scientific evidence, Kendall said. She added that best practice also calls for a teacher trained specifically to teach sex education.

Having an opt-out process — as Wisconsin does — rather than having each family opt in to the curriculum is also preferred, Kendall said.

Kim Shefchik, a physician assistant who specializes in obstetrics and gynecology at Bellin Health Generations, said it's important to have conversations about sexual health with students. However, teenagers are also facing a mental health crisis with soaring levels of anxiety. Conversations around sexual health should be empowering and cover ways to maximize safety, not just invoke fear, she said.

“When we just look at sex from the lens of disease and pregnancy, we perpetuate the stigma of talking about this,” she said.

Shefchik said conversations should also look at sexual health holistically, not just at disease and pregnancy.

The state's recommendations emphasize marriage and abstinence

The state statute emphasizes talking about marriage during these lessons. There’s language on teaching the positive connection between marriage and parenting, the socioeconomic benefits of marriage and that abstinence is the “preferred choice of behavior for unmarried pupils.”

Kendall said the emphasis on marriage is rooted in certain moral claims, more than evidence or practice.

The population of single adults has grown over the past few decades, according to data from Pew Research Center that show about four in 10 adults ages 25 to 54 aren't married or living with a partner. And the average age of first-time marriages in the U.S. is between 27 and 29, well up from the 1960s, according to the U.S. Census Bureau.

"Arguing for abstinence-only education in the U.S. is arguing against the way the vast majority of people live their sexual and relational lives," she said.

Kendall said public schools have an obligation to make sure all students have a place, but certain conversations around marriage risk leaving out students whose parents aren't married or who identify as LGBTQ — if only heterosexual marriage is discussed.

She also pointed out that the state statute includes a nondiscrimination statement. It says instructional materials and methods shouldn't discriminate against a student's race, religion, sexual orientation or cultural background. It also says it shouldn't discriminate against a student who is sexually active, but that doesn't prohibit the use of abstinence-centered material.

Politics have shaped Wisconsin's sex ed laws

Wisconsin’s statutes around teaching human growth and development are littered with the remnants of Democratic- and Republican-controlled legislatures past, Kendall said.

Language around providing medically accurate information is usually adopted by Democratic-controlled legislatures, whereas language focusing on abstinence usually comes from Republican-controlled legislatures.

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Reach AnnMarie Hilton at ahilton@gannett.com or 920-370-8045. Follow her on Twitter at @hilton_annmarie.

This article originally appeared on Appleton Post-Crescent: Wisconsin public schools aren't required to teach sexual education