But birth control is just the tip of the iceberg, advocates say. There are a number of other women's health benefits that are also at risk.
At or near the top of the list is guaranteed coverage of maternity services on the individual insurance market. Before the health law, it was unusual for plans in the individual market to pay for maternity services. But the Affordable Care Act required that care be included as one of the 10 essential health benefits
that all individual plans must cover.
In 2009, the year before the health law passed, just 13 percent of individual plans that were available to a 30-year-old woman in all the state capitals offered maternity benefits, according to an analysis
by the National Women's Law Center.
Some plans offered maternity services as an add-on through a special rider that paid a fixed dollar amount, sometimes just a few thousand dollars, the study found. But even with a rider, a woman's financial exposure could be significant: The average total payment for a vaginal birth was $18,329 in 2010, according to a study
(PDF) by Truven Health Analytics.
Women were also generally charged higher rates for health insurance on the individual market before the law.
According to the National Women's Law Center's analysis, 60 percent of best-selling individual plans in 2009 charged a 40-year-old non-smoking woman more than a 40-year-old man who smoked, even in plans that didn't include any type of maternity coverage. That inequity disappeared under the health law, which prohibited insurers from charging women higher rates than men for the same services.
"Our concern is going back to a world where insurance companies are writing their own rules again, and returning women to those bad old days in health care and losing all the progress we've made," said Gretchen Borchelt, vice president for reproductive rights and health at the law center.
Several other women's preventive health services could be on the line if the health law is repealed or changed. Some may be easier to get rid of than others, say women's health policy experts.
Under the law, preventive services that are recommended by the U.S. Preventive Services Task Force have to be covered without cost sharing. The task force, an independent panel of medical experts, evaluates the scientific evidence for screenings, medications and services and publishes several new or updated recommendations annually. Current recommendations
that affect women include guidelines for screening for breast and cervical cancer and testing for the BRCA 1 and 2 genetic mutations that increase women's risk of breast cancer.
"Coverage of those services can't be changed without a change to the statute" that created the health law, said Dania Palanker, an assistant research professor at Georgetown University's Center on Health Insurance Reforms. If the law is repealed, then that could happen.
There's another group of required preventive services for women that could be even easier to eliminate, however.
Under the law, women's preventive services that are endorsed by the Health Resources and Services Administration have to be covered by most insurers without cost sharing as well. In 2011, the Institute of Medicine proposed a list of eight preventive services
that should be covered, and HRSA adopted them. Among them was the requirement that most insurers cover all FDA-approved contraceptives without charging women anything out-of-pocket.
Also included were requirements to cover well-woman visits at least once a year, screening for gestational diabetes, counseling and screening for sexually transmitted infections, breastfeeding support, counseling and supplies, and screening and counseling for domestic violence.
A committee of women's health providers led by the American College of Obstetricians and Gynecologists has proposed an update
to the current guidelines that is under review by federal officials.
"We expect action will be taken before the end of this administration," said Palanker.
But the Trump administration may not have the same ideas about which preventive benefits
(PDF) for women should be endorsed. The new secretary of Health And Human Services could opt for different decisions than the Obama administration.
"What they can endorse they can also unendorse," said Adam Sonfield, a senior policy manager at the Guttmacher Institute, a research and advocacy organization for reproductive health based in Washington, D.C.
Finally, many of the details about what's required to comply with the law have been in the form of thousands of pages of regulations and guidance. A new administration could write different rules or just not enforce the ones that are on the books, advocates warn.
Take birth control.
Some health plans initially interpreted the requirement to cover FDA-approved contraceptives to mean that if they covered birth control pills, for example, they didn't have to cover other hormonal methods of contraception such as the vaginal ring or patch. Federal officials under Obama have declared that insurers couldn't pick and choose; they had to cover all 18 FDA-approved methods
(PDF) of birth control.
"A lot of the pieces of the preventive services benefits that clarify and make the coverage real and strong has been through [federal officials'] guidance [that interprets the health law], and there is fear that could be changed," Palanker said.