Republican states challenging federal regulations providing for time off for an abortion under the Pregnant Workers Fairness Act will face a substantial hurdle as the rule mirrors well-established practice under Title VII of the 1964 Civil Rights Act, employment attorneys said Monday.

When drafting the PWFA, Congress used the phrase “pregnancy, childbirth, and related medical conditions” from Title VII , as amended by the 1978 Pregnancy Discrimination Act, said Kate Mueting, of Sanford Heisler Sharp. The law defines “pregnancy, childbirth, and related medical conditions” to include abortion, she added.