Human and laboratory animal test systems available for detection of reproductive failure

The human reproductive system in both males and females is highly sensitive to a variety of occupational and environmental hazards. Damage can occur in many target tissues in the fetus and adult, leading to reproductive failure. A more comprehensive awareness of such potential damage is essential to reduce the relatively high rates of reproductive failure in the human population. In this article, human and laboratory animal test systems available for the study of reproductive failure are discussed. Endpoints measured in these systems include adult infertility, spontaneous abortion, growth retardation, stillbirths, birth defects, and functional disease states in the offspring, such as cancer, mental retardation, and sterility. Validation of laboratory animal test systems with known human teratogens is urged. Routine surveillance of the human population via recording of the incidence of spontaneous abortion along with cytogenetic analysis is recommended, as well as semen analysis of occupationally-exposed males. The need for more extensive study of the association between paternal exposure and reproductive outcome is emphasized. Test schemes for the early detection of reproductive failure in the human population and for the identification of agents capable of causing this effect are proposed.