A mechanistic-based approach for assessing chemical hazards to parturition.

Evaluations of environmental hazards to pregnancy often overlook the potential for chemicals to disrupt the final event, childbirth. There are relatively few epidemiologic studies on this topic and even fewer toxicologic investigations. Mechanistic-based approaches offset many of the difficulties that are anticipated with intact laboratory animals, such as interspecies variability in the initiating events, and may allow for rapid and relevant assessment of potential chemical hazards. In vitro systems based on knowledge of the cellular events that underlie parturition may, therefore, facilitate investigation of toxicologic aspects of parturition. Nonetheless, limitations of in vitro mechanistic-based approaches exist. Ultimately, the greatest understanding of risk to pregnancy from environmental chemicals is likely to result from the collaborative efforts of laboratory scientists and epidemiologists.