CHARLOTTE, NC - SEPTEMBER 4: Women Democrat members of the U.S. House of Representatives gather onstage after speaking at the 2012 Democratic National Convention on September 4, 2012 in Charlotte, North Carolina. (Photo by Bonnie Jo Mount/The Washington Post)

This week a bipartisan group of four senators introduced a bill, dubbed the Pregnant Workers Fairness Act. It borrows language from the Americans With Disabilities Act and seeks to strengthen and clarify the “reasonable accommodations” that employers must make for pregnant employees.

The bill in and of itself it significant. But it's also significant in another sense -- in that it marks a clear and public turn away from decades of feminist thinking about the absolute interchangeability of male and female workers.

Advocates say the bill is built around a series of modern and pragmatic ideas that will directly aid the estimated 250,000 women each year who ask their employers for reasonable pregnancy-related work accommodations connected to their pregnancies -- we’re talking bathroom breaks, time for doctor’s appointments, restrictions on lifting and/or a nearby water bottle to remain hydrated – and see those requests denied. (That quarter-million women each year figure, by the way, comes from a 2014 survey conducted by the National Partnership for Women and Families.) What’s worse, at least some of these women instead wind up losing their jobs and the health insurance benefits that come with them.

Unlike most bills working their way through Congress, this one seems to have a good chance of passage. After all, a non-binding and preliminary version on the concepts contained in the bill passed the Senate earlier this year by a unanimous vote. And states as politically disparate as New Jersey, West Virginia, Delaware, New York, Maryland, Minnesota, Nebraska, North Dakota and Illinois have passed state-level versions of the Pregnant Workers Fairness Act in just the last two years. The same has happened at the local level in New York City, Philadelphia, Washington, D.C., and, in a more limited fashion, Pittsburgh.

The reason the bill has legs is because people on many sides of the issue have an interest, according to Emily Martin, a vice president and general counsel at The National Women’s Law Center. There are the lawmakers deeply concerned about the welfare of fetuses, there are elected officials worried that low-wage working women pushed out of their jobs will wind up in need of public assistance, and there are legislators generally inclined to advance laws that expand women’s rights.

Passage is never assured in today's Congress, but this bill has clearly gained attention for a reason.

It’s worth noting that all of this is happening at a time when entire birthing centers, online communities and documentaries have stormed the culture with the idea that pregnancy need not be a universally medical-ized and medicated 40-week stretch of vulnerability and disempowerment capped by a frightening delivery.

But Martin thinks something else has happened that should not be missed: The way that Americans think about disabilities and even what employers understand to be a “reasonable” accommodation. This has shifted dramatically in the last 25 to 30 years. Disability has, in short, become less stigmatized, and the legal protections for workers with short- and long-term disabilities have become far clearer.

But pregnant women – particularly the disproportionate share of women who make up the low-wage workforce in the home health care, retail, warehouse and hospitality and service industries – often found themselves unable to access some of the same temporary work assignments and minor workplace accommodations that most employers will (and legally must) extend to someone who has injured their back or knee.

All that came to a head in a March Supreme Court case, Young v. UPS, in which the court decided in favor of a once-pregnant female employee. Back in 2006, UPS put a then-pregnant driver, Peggy Young, on unpaid administrative leave and stripped of her health insurance. Young’s doctor had advised her not to lift more than 20 pounds during her pregnancy -- something her job rarely required. So she asked the company for a temporary light-duty assignment — an option extended to UPS workers injured on the job and even those who have lost their commercial driver’s license due to a DUI charge – or a plan to deal with the rare package on her route weighing more than 20 pounds. The company refused, saying Young was too much of a risk. And, the company’s legal obligations regarding temporary light-duty assignments were limited to the injured and the disabled, according to UPS.

The court issued a complicated ruling that amounted to a legal win for Young. But it did not clarify precisely what accommodations employers must make for pregnant workers. And apparently some clarity is needed, urgently.

After all, about 71 percent of the women needed more frequent bathroom breaks while pregnant, but a full 42 percent said they never asked their employers to accommodate that, according to that same 2014 survey.

The survey doesn’t indicate why the women remained silent about their needs. That might have required pollsters to dig deep into the now-entwined weeds of feminism and mainstream understandings of equality. Women today have become the sole or primary breadwinners in about 40 percent of families with kids in the United States.

The temporary disability model, advocates of the Pregnant Workers Fairness Act say, could provide clearer and more consistent protections for women working all kinds of jobs while managing all types of pregnancies. And, for the American family, that increasingly matters more than feminist ideals developed decades ago.