A stool. A bottle of water. Lighter duty. A bathroom break. On Tuesday, Delaware Gov. Jack Markell (D) is expected to sign into law provisions that would ensure that pregnant workers receive such reasonable and fair accommodations to stay on the job.

The Pregnant Workers Fairness Act, which was sponsored by state Sen. Bethany Hall-Long (D) and co-sponsored by conservative Republicans, sailed through the state legislature in a few months and passed with a rare unanimous vote. The measure had the backing of civil rights and other groups to the left of the political spectrum, and the business community to the right.

As a similar bill languishes in Congress, Delaware is the latest in a growing number of states and localities to pass what lawmakers call “common sense” legislation to keep pregnant women working with certain accommodations, if warranted, as long as they don’t pose undue hardship on businesses.

In the past 18 months, measures to ensure such accommodations have passed unanimously in New York City, Philadelphia, Providence, R.I., and in West Virginia. Bipartisan efforts have resulted in laws in Maryland, Minnesota and New Jersey – where only one lawmaker voted against the bill.

In late August, Illinois Gov. Pat Quinn (D), a champion, signed the Pregnant Workers Fairness Act into law. It, too, had passed the state legislature in a unanimous vote. “No pregnant woman should have to choose between having her baby and keeping her job,” Quinn said at a news conference.

California and Hawaii already have laws that guarantee reasonable accommodations for pregnant workers. And similar bills are pending in several states —  including Georgia, Missouri, New York, Pennsylvania, Rhode Island and Wisconsin — and the District of Columbia. Many laws also include provisions that guarantee reasonable accommodations to support breastfeeding, ensuring that workers can have breaks and dedicated space to pump breast milk.

“This makes common sense not just for maternal and child health, but as good, sound economics,” said Delaware’s Hall-Long. “Women are more and more the lead breadwinners of their families. If you make them use up all their leave before they give birth, or terminate their employment because they need an accommodation, you have created an economic situation for that family that then may need to rely on Medicaid, and other public social supports.

“And businesses with a strategic vision embraced this,” she continued. “A simple accommodation is so much easier than laying someone off, terminating them, then having to bring someone else on and retrain them.”

That’s what happened in Delaware to Nicole Villanueva. When the hospital worker developed cardiac arrhythmia that caused shortness of breath while she was pregnant, she asked her employer if she could do lighter clerical work instead of more physically taxing patient work. Her employer refused, saying she hadn’t been injured on the job, and she was fired. She sued, and later settled out of court.

For state Rep. Mary E. Flowers (D-Chicago), who shepherded the bill through the Illinois General Assembly, it was stories like that of Bene’t Holmes, a 25-year-old single mother, that moved her to action.

In 2013, Holmes was working at Wal-Mart and, during her fourth month of pregnancy, began having trouble lifting 50-pound boxes. Holmes requested temporary duties that would be less physically strenuous, on her doctor’s orders. She said her store manager denied the request, saying that Wal-Mart’s policy provided accommodations for workers with disabilities or on-the-job injuries. The day after the request was denied, Holmes had a miscarriage.

“She miscarried her child, and only because the employer did not think enough of her, as a woman, as a human being, to make reasonable accommodations, the same thing you would do for any other person who hurt themselves playing golf or basketball or who was born with a disability or had an accident,” Flowers said. “This law is about treating pregnant workers with dignity and respect, and giving them the same accommodations as you would give workers with a disability or injury.”

Illinois, like the laws in other states, gives businesses the right to refuse the accommodations if they pose an undue hardship. “But these are pretty simple and temporary accommodations,” Flowers said. “I guarantee you, it will be cheaper for employers to make reasonable accommodations than to end up being sued in court.”

In recent years, a rising number of lawsuits and discrimination claims filed with the Equal Employment Opportunity Commission show that pregnant women have been fired for requesting to carry a water bottle to stay hydrated, on their doctors’ orders. Many who have asked for lighter duty, a break from heavy lifting or a desk job instead of driving or going out on patrol as a police officer, have been terminated or forced to use up all their paid and unpaid leave before giving birth.

Low-wage workers in retail, health and service industries are often hit the hardest, according to EEOC data, as are women in fields that traditionally have had few women, such as law enforcement. In July, the the EEOC issued new guidelines making clear that refusing reasonable accommodations to pregnant workers is illegal.

Giving pregnant workers reasonable and fair accommodations is at the heart of a controversial case that the Supreme Court has agreed to hear. In Young vs. UPS, Peggy Young, a United Parcel Service delivery driver in Landover, Md., asked for a temporary desk assignment to avoid lifting heavy packages during her pregnancy.

Other UPS workers had been given such accommodations. UPS denied Young’s request in large part because she hadn’t been injured on the job.

Although Congress passed the Pregnancy Discrimination Act in 1978, Emily Martin, vice president and senior counsel for the National Women’s Law Center, said that the law is confusing and that different courts have interpreted it to mean different things.

To clarify the law, Democrats in Congress have been spearheading an effort to pass a federal Pregnant Workers Fairness Act. President Obama, at the White House Summit on Working Families in June, called on lawmakers to pass it. “Right now, if you’re pregnant, you could potentially get fired for taking too many bathroom breaks — clearly from a boss who has never been pregnant — or forced [to take] unpaid leave,” Obama said. “That makes no sense.”

The bills, which are sponsored by Sens. Robert P. Casey Jr. (Pa.), Jeanne Shaheen (N.H.) and 28 other Senate Democrats, and by Reps. Carolyn B. Maloney (N.Y.) and Jerrold Nadler (N.Y.) and 163 other House Democrats. Caught in the mire of bitterly divided partisan politics, the proposals have gone nowhere.

Emily Martin, vice president and senior counsel for the National Women’s Law Center, said polls show that a majority of voters favor policies that support families. Yet, as she and others have been lobbying for a pregnant worker fairness bill, they have not been able to drum up a single Republican supporter.

“There isn’t any articulated opposition from Republican offices. And giving workers a stool rather than making them stand all day – it’s very hard to articulate why you’re against that,” she said. “A lot of staff smile and nod and say that this makes a lot of sense, then we never hear from them again.”

Which is one reason why efforts have turned to the states, where the movement has been picking up steam.

Said Delaware’s Hall-Long, “It’s really important that folks understand that pregnancy isn’t a Democratic or Republican issue. It affects all of us.”