Reproductive toxicity spontaneous abortions

Lead is known to cause reproductive and developmental toxicity. Decreased sperm counts and abnormal sperm development have been reported in male workers heavily exposed to lead. Increased incidences of spontaneous abortion have been reported in female lead workers as well as in the wives of male lead workers (13). Lead crosses the placenta and has been found to cause irreversible neurologic impairment to the fetus at maternal blood levels as... 

Reproductive Toxicity. Increased miscarriages were reported in one study of nurse-anesthetists exposed to trichloroethylene and other solvents (Corbett et al. 1974). A retrospective case-control study has should an approximate 3-fold increase in spontaneous abortion in women exposed to trichloroethylene and other solvents (Windham et al. 1991). Significant effects on sperm parameters were not observed in men occupationally exposed to trichloroethylene (Rasmussen et al. 1988). Adverse reproductive effects were not noted in humans that ingested water contaminated with trichloroethylene and other solvents (Byers et al. 

Reproductive Toxicity. Reproductive data are available on women occupationally exposed to benzene (Mukhametova and Vozovaya 1972 Vara and Kinnunen 1946). The data suggest spontaneous abortions, menstrual disturbances, and ovarian atrophy. These studies are limited by the difficulty in identifying appropriate controls, problems in controlling for concomitant exposures to other chemicals, and inadequate follow-up. Only one study was found that described the reproductive effects on men exposed to benzene (Stacker et al. 1994). There are some data available from inhalation studies on reproductive effects of benzene in animals. Although there are data on adverse gonadal effects (e.g., atrophy/degeneration, decrease in spermatozoa, moderate increases in abnormal sperm forms) (Ward et al. 

Reproductive toxins cause spontaneous abortions, birth defects, and sterility. The design of a toxicity study should meet the objectives intended and minimize the pain, distress, and suffering of the test animals. The study should gather as much information as possible about the substance to be... 

Reproductive Toxicity. Occupational exposure to metallic mercury has not been shown to result in statistically significant effects on male fertility (Alcser et al. 1989 Lauwerys et al. 1985). However, an increase in the rate of spontaneous abortions may occur (Cordier et al. 1991). A spontaneous abortion occurred in a female after ingesting an acute dose of mercuric chloride (Afonso and de Alvarez 1960). There were no studies available on dermal exposure to metallic, inorganic, or organic mercury. 

Human infertility can result from the action of xenobiotic chemicals on the female reproductive system, the male reproductive system, attack on the fetus, and the induction of effects in utero that are manifest during adulthood, giving rise to a programmed infertility. Spontaneous abortion can ensue when pregnant women are exposed to toxic chemicals such as those in disinfection byproducts produced by the chlorination of drinking water. 

Coal Tar Products. An excess of breast cancer cases in St. Louis Park, Minnesota, was tentatively associated with coal tar contamination of the water supply (Dean et al. 1988). However, in a subsequent analysis of these data, the Minnesota Department of Health (1985) concluded that this study did not provide adequate evidence to associate breast-cancer with coal tar creosote-contaminated water (for a detailed discussion of these data, see Section 3.2.2.7 Cancer). No adverse effects on sperm characteristics were reported in male workers exposed to coal tar pitch volatiles in an industrial setting (Ward 1988). In addition, no adverse reproductive outcomes were detected in a survey of inhabitants of a housing development built on an abandoned creosote factory site, which was known to be contaminated with creosote (Agency for Toxic Substances and Disease Registry 1994). A retrospective study of dermal exposure to coal tar found no increased risk of spontaneous abortion associated with exposure to coal tar during pregnancy, but this was a small study and was unlikely to have sufficient resolution to detect a modest increase in risk (Franssen et al. 1999). 

Reproductive and developmental effects Higher risk of spontaneous abortions, developmental toxicant in rats and mice. Adverse developmental effects in animals include greater incidence of post-implantation loss, decreased fetal body weight, reduced ossiAcation and decreased number of live fetuses... 

This chapter presents the toxicological evidence for lead as a potent reproductive and intrauterine developmental toxicant. Sections of the chapter deal with male and female gametotoxicity, embryotoxicity, fetotoxicity, and various gross indices of fetal injury such as spontaneous abortion, stillbirth, and neonatal survival. Prenatal developmental effects as they affect the whole organism are presented here, while prenatal effects on various systems and organs are discussed in system- and organ-specific chapters. For example, developmental neurotoxicity of lead as it occurs in utero is discussed in Chapter 12. 

By the first decade of the twentieth century, recognition of reproductive and prenatal harm and subsequent responses greatly reduced the adverse effects of lead in utero during worker pregnancies through constraints on women of childbearing age in the lead workplace. In particular, the prevalence and incidence of such gross Pb toxicity outcomes as spontaneous abortions, stillbirths, and depressed early natal survival declined markedly. 

Much of the evidence for the adverse reproductive effects of selected toxicants will be based on cases involving wildlife exposiues to environmental contaminants or on the experimental results of research exposing laboratory animals to large pharmacological doses of potential toxicants. When available, data are presented from accidental or intentional human and domestic animal exposures to toxicants associated with riot control and chemical warfare or with environmental catastrophes during which incidences of infertility, spontaneous abortion, and teratogenesis have been traced over the course of a number of years. 

The reproductive toxicity of high-level lead exposure is well known and supported by an extensive literature (Rom, 1976). Much of this literature focuses on an increased incidence of spontaneous abortions and stillbirths associated with lead exposures in the workplace (Oliver, 1911 Lane, 1949). Based on a renewed awareness of these earlier findings, women have been largely excluded from occupational lead exposure. Therefore, exposures have declined and the attention of researchers and regulatory agencies has shifted to more subtle manifestations of lead-related reproductive toxicity in the general population. 

Toxic quantities of lead in the human body impact the reproductive processes of both men and women. An increased incidence of spontaneous abortions has been documented in female lead workers and in the wives of male lead workers, i.e. persons working in lead smelting or manufacture of lead containing products. Male lead workers with blood lead concentrations of 53 to 75 ug/dl have been reported to have decreased sperm counts as well as altered morphology of the sperm. [4]. 

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