Pregnancy, disability, and maternity leaves.

The historical treatment of pregnant working women stems from the traditional societal attitude that a woman's role is exclusively one of wife and mother. As women began entering the workforce during the Industrial Revolution, many states attempted to protect women from the unhealthy working conditions existing at that time. States enacted statutes that attempted to shield women by limiting hours of work, specifying maximum weights to be lifted, and prohibiting them from performing certain types of work.