The Pregnancy Discrimination Act (PDA) of 1978 (Pub. L. 95–555) is a United States federal statute. It amended Title VII of the Civil Rights Act of 1964 to "prohibit sex discrimination on the basis of pregnancy."

The Act covers discrimination "on the basis of pregnancy, childbirth, or related medical conditions." Employers with fewer than 15 employees are exempted from the Act. Employers are exempt from providing medical coverage for elective abortions, unless the mother's life is threatened, but are required to provide disability and sick leave for women who are recovering from an abortion.

The law was passed as a direct response to the United States Supreme Court decision in General Electric Company v. Gilbert (1976), in which the Court held that pregnancy discrimination was not a form of sex discrimination under the Civil Rights Act of 1964.

In March 2015, the Supreme Court of the United States' decision in Young v. United Parcel Service, provided additional clarity on whether and when employers are required to provide work-related accommodations to pregnant employees. The lawsuit stemmed from United Parcel Service's refusal to accommodate a 20-pound lifting restriction of a driver during her pregnancy. Because Ms. Young could not lift the required 70 pounds for drivers, UPS did not allow her to work. Ms. Young provided evidence that a number of employees received accommodations while suffering similar or more serious disabilities. According to the testimony of one UPS employee, the only time a light-duty request seemed to become an issue occurred when the request was made by a pregnant employee. The Court held that a pregnant employee can make a prima facie, meaning a plausible case of discrimination, by showing that "she belongs to the protected class, that she sought accommodation, that the employer did not accommodate her." The Court further held that a plaintiff can meet a summary judgement standard "by providing evidence that the employer accommodates a large percentage of nonpregnant workers while failing to accommodate a large percentage of pregnant workers."

Pregnancy is considered a temporary disability in the eyes of the law, meaning that the treatment of pregnant employees falls under the same jurisdiction as disabled employees. Treating a pregnant employee in a way that would violate disability standards is also a violation of the Pregnancy Discrimination Act (PDA).

If an employee is temporarily unable to perform her job due to pregnancy, the employer must treat her the same as any other temporarily disabled employee; for example, by providing light duty, modified tasks, alternative assignments, disability leave, or leave without pay. An employer may have to provide a reasonable accommodation for a disability related to pregnancy, absent undue hardship (significant difficulty or expense)."

The Geduldig v. Aiello (1974) case involved a pregnant woman who was denied medical benefits under her disability insurance, citing the Fourteenth Amendment, and claiming sex discrimination. The U.S. Supreme Court concluded that there was no evidence of sex discrimination, and that there was no violation of the Equal Protection Clause, as men and women were receiving equal protection under the insurance program, and that because men cannot become pregnant, offering protections for pregnancy would constitute unequal treatment. The court in this case also did not use a heightened level of scrutiny, meaning that the court did not treat this case as one of high importance. This treatment was criticized by Justice Brennan in a dissent in which he argued that physical gender differences should not lead to unequal compensation, and that gender cases should be decided using the strict scrutiny standard.

General Electric v. Gilbert (1976) in many ways was influenced by the decision of Geduldig v. Aiello, as the Supreme Court again found no evidence of discrimination. Specifically, in General Electric v. Gilbert the Supreme Court ruled that it was legal for employers to exclude pregnancy-related conditions from employee sickness and accident benefits plans. Again, Justice Brennan dissented, noting for a second time that women were receiving unequal compensation. Due to this dissent and the dissent from Geduldig v. Aiello, U.S. Congress saw a gap in protections and created the Pregnancy Discrimination Act two years later in response.