Over the past two decades, several U.S. companies have sought to bar women from jobs that expose them to potential reproductive hazards, justifying these exclusionary policies by their professed concerns for the well-being of unborn children and potential liability. Although recent court cases have stimulated academic interest in this issue, a historical review of the public health and medical literature reveals that this debate is not new. To understand the logic behind the emergence of "fetal protection" policies, one must examine the scientific history of occupational teratogens and the socio-political and economic forces that have driven scientific research in this field. Using lead as an example, the author argues that research on the reproductive hazards of employment has historically emphasized the risks to women and downplayed the risks to men. This results in environmental health policies that do not uphold the ultimate goal of occupational safety for all workers, but rather reinforce the systemic segregation of men and women in the workplace. Although the political struggle over exclusionary policies has a feminist orientation, it also has important class dimensions and ultimately must be viewed within the broader context of American capitalist production.