While pregnancy is not necessarily a disability, the EEC enforces the (Federal) Pregnancy Discrimination Act (PDA)  From https://www.eeoc.gov/laws/types/pregnancy.cfm .

Pregnancy Discrimination

Pregnancy discrimination involves treating a woman (an applicant or employee) unfavorably because of pregnancy, childbirth, or a medical condition related to pregnancy or childbirth.

Pregnancy Discrimination & Work Situations

The Pregnancy Discrimination Act (PDA) forbids discrimination based on pregnancy when it comes to any aspect of employment, including hiring, firing, pay, job assignments, promotions, layoff, training, fringe benefits, such as leave and health insurance, and any other term or condition of employment.

Pregnancy Discrimination & Temporary Disability

If a woman is temporarily unable to perform her job due to a medical condition related to pregnancy or childbirth, the employer or other covered entity must treat her in the same way as it treats any other temporarily disabled employee. For example, the employer may have to provide light duty, alternative assignments, disability leave, or unpaid leave to pregnant employees if it does so for other temporarily disabled employees.

Information provided by Andrew Vaughn, MD MPH