Soon after Alabama emergency medical technician Kimberlie Durham discovered she was pregnant, she said her work situation felt untenable. Her duties required her to carry stretchers and other equipment but her doctor said she should not lift anything more than 50 pounds.

Durham's employer, Rural/Metro Corp., an Arizona-based emergency services provider, said it could only offer unpaid leave for six months until she had her baby and refused to reassign her to a less strenuous job, according to a lawsuit she filed. Durham's lawyers said the company's decision clashed with federal laws that protect pregnant women in the workplace.

An Alabama federal judge ruled against Durham, and now she's appealing to the U.S. Court of Appeals for the Eleventh Circuit. Her case is the latest to test the scope of a 2015 U.S. Supreme Court decision that confronted the contours and requirements of the Pregnancy Discrimination Act.

The federal appeal comes amid a heightened national dialogue about the alleged pervasiveness of pregnancy discrimination across workplaces. A New York Times investigation last year concluded that “many of the country's largest and most prestigious companies still systematically sideline pregnant women.”

Durham claimed Rural/Metro discriminates against pregnant women because the company allows light-duty reassignments to employees injured on the job but not to expecting mothers.

Rural/Metro, represented by a team from Constangy, Brooks, Smith & Prophete, has denied any wrongdoing and has argued there was no position open for Durham when she requested a light-duty accommodation. An attorney for the company did not immediately respond to a request for comment.

Civil rights groups and the U.S. Equal Employment Opportunity Council are now backing Durham in her appeal as friends of the court. The EEOC said the trial judge's ruling runs counter to the Supreme Court's 2015 decision in Young v. United Parcel Service. The 6-3 court bolstered the federal law that protects women against pregnancy discrimination, but the justices did not clearly tell employers when they are required to provide light duty to an employee.

“The EEOC has a strong interest in ensuring that Young is applied correctly. The court's misapplication hampers the EEOC's enforcement efforts and makes it more difficult for individuals acting as private attorneys general to pursue meritorious claims,” the EEOC said in its amicus brief. “A reasonable jury could find that Rural/Metro's policy imposed a 'significant burden' on pregnant employees like Durham, who lost her job because of its failure to accommodate her.”

Durham is represented by the American Civil Liberties Union Foundation Women's Rights Project, ACLU of Alabama and Heather Leonard of Birmingham. Her attorneys also point to the Supreme Court's ruling in Young. The trial judge's ruling against Durham essentially means that “the Young case might as well not have been decided,” Durham's lawyers argued in their opening brief, filed earlier this month.

Nearly two-dozen civil rights groups, including a Better Balance, The National Women's Law Center and the National Employment Law Project, have pressed the appeals court to reverse the lower court's decision.

“The standard announced in Young places pregnant women on an equal plane at work by requiring employers to make accommodations for pregnant employees to the same extent they do so for their nonpregnant coworkers who have a similar ability or inability to work,” wrote Elizabeth Morris, deputy director of the San Francisco-based Center for WorkLIfe Law.

Morris said an Eleventh Circuit ruling against Durham “would give employers license to treat pregnant women worse than their non-pregnant colleagues and frustrate the [PDA's] animating purpose of ensuring pregnant women are able to earn an income.”

Durham's case, which hasn't been set for argument, marks the latest action by lower courts exploring the reach of the Supreme Court's decision.

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In 2016, the U.S. Court of Appeals for the Second Circuit ruled in favor of a corrections officer in New York who had challenged the dismissal of claims alleging pregnancy discrimination. The appeals court concluded the plaintiff “has presented sufficient evidence to support a pregnancy discrimination claim under Young.” More recently, the Eleventh Circuit said the PDA obligates employers to accommodate workers not just during pregnancy, but also once they return to work and are breastfeeding.

The Supreme Court's decision in the Young case revived pregnancy discrimination claims but left unresolved myriad issues about how courts should apply the ruling, according to a 2016 article published by the University of Pennsylvania School of Law. The article argues the Supreme Court did not specify how to best compare employees.

In a client advisory last year, Constangy Brooks lawyers noted that “most employers have instituted more flexible accommodation practices for pregnant workers and women returning to work post-childbirth since the U.S. Supreme Court's 2015 decision in Young v. United Parcel Service and the enactment of the federal Nursing Mothers Act.”

The ACLU is handling several cases involving alleged pregnancy discrimination and policies that directly or indirectly punish women who are expecting a child. A class action alleges an AT&T Mobility policy unfairly discriminates against pregnant women, and another case says seniority and benefits are stripped for pregnant dock workers. AT&T's lawyers at Paul Hastings have denied the discrimination claims.