TAMARA BULEY MISSED SEVERal days of work as a saleswoman in a clothing store because she didn't feel well. She soon found out she was pregnant. The company fired her, claiming she was not entitled to sick leave during her first year of work.

After Buley filed a complaint, her former employer challenged a Montana law that requires companies to give pregnant workers "reasonable leave." The company contends that the state law conflicts with a federal law that calls for employers to treat pregnancy like any other disability. The issue may be settled when the U.S. Supreme Court hears a similar suit this fall.

The questions raised go beyond the courts, and how they are resolved could have a major effect on small businesses. Ninety percent of working women, who comprise almost half of the work force, expect to have children. Most cannot afford to leave their jobs permanently after giving birth.

The debate over pregnancy and child-care leave for workers is growing faster than a newborn. Congress is considering a bill that would protect parents' jobs, and several prestigious groups, including the Yale Bush Center Advisory Committee on Infant Care Leave, have issued recommendations. While the Court's upcoming decision should clarify whether special pregnancy benefits are discriminatory, tough questions remain about how a system should be structured. Should workers be guaranteed a job to return to? Should workers be paid during pregnancy leaves?

Pregnancy benefits have far-reaching value to employees and their families, but many small companies object to the extra burden. "Small businesses have fewer bodies to move around to replace a key employee who goes on leave," notes Neil O'Farrell, emerging-business coordinator at Coopers & Lybrand. And holding a job open could be a strain. "Small companies can't guarantee anything," says Robert Vincent, president of Geospectra Corp., a small Ann Arbor, Mich., company that makes scientific software. "They can't predict the future enough to say, 'In a few months, you can return to your job."

Leaves could also raise costs, since companies might have to train new employees to fill in temporarily. And the Bush Center, for one, proposes that companywide contributions to an insurance fund pay workers 75% of their salaries during the first three months of leave. "Employers already spend a good part of their payrolls on benefits," says James Klein, manager of pensions and employee benefits at the U.S. Chamber of Commerce. "If pregnancy leave comes, it will come at the expense of something else."

The bill before Congress calls for 18 weeks of unpaid leave for parents of newborn, recently adopted, or seriously ill children. It also recommends 26 weeks of job-protected leave for other nonoccupational disabilities. Congress may ultimately leave the matter for states to decide, but some form of pregnancy and child-care leave seems on the way.