"Making Pregnancy Work: Overcoming the Pregnancy Discrimination Act's Capacity-Based Model" by Professor Joanna L. Grossman and Gillian Thomas was published in Yale Journal of Law & Feminism, Vol. 19, No. 2, 2009, Hofstra Univ. Legal Studies Research Paper No. 09-10.

ABSTRACT:
This article considers the gaps and obstacles in current law faced by the pregnant woman whose job duties may conflict with pregnancy's physical effects. While there is no inherent conflict between pregnancy and work, women in physically strenuous or hazardous occupations, from nursing to law enforcement, routinely confront situations in which they are physically unable to perform aspects of their job or, though physically able, they seek to avoid certain tasks or situations because of the potential risks to maternal or fetal health. The Pregnancy Discrimination Act of 1978 (PDA) broadly protects against "pregnancy discrimination," but it provides absolute rights only to the extent a pregnant woman is able to work at full capacity, uninterrupted by pregnancy's physical effects. To the extent that the law grants the pregnant worker with temporary physical limitations "affirmative" rights, such as the right to workplace accommodation, it is only on a comparative basis - that is, only to the extent those rights already are provided to "similarly situated" temporarily disabled employees. In this way, pregnancy continues to inhibit equal employment opportunity for millions of women, three decades after the PDA's passage.

After briefly examining the medical literature documenting the conflicts between pregnancy and certain kinds of work, as well as the law as applied to pregnant workers who are fully capable or fully incapable due to the effects of pregnancy or childbirth, we consider the predicament of women in physically demanding fields whose work capacity is partially diminished by pregnancy. We focus here on the problem of access to "light-duty" work - temporary alternative job assignments that accommodate the pregnant worker's limitations. Without such accommodation, the pregnant firefighter or home health care aide whose doctor directs her to avoid heavy lifting or other tasks is faced with a Hobson's choice: ignore medical advice and continue to perform all job duties, or stop working altogether, usually sacrificing wages and other benefits for several months. We describe the limits of the existing PDA framework for protecting these pregnant workers, and suggest litigation strategies for maximizing pregnant workers' rights under current law. These include re-framing the "similarly situated" analysis for disparate treatment challenges to light-duty policies, and exploring the untapped potential of the disparate impact theory in the light-duty context.