The genitourinary system encompasses 2 major organ systems, the reproductive and the urinary systems. Successful reproduction requires interaction between 2 sexually mature individuals. Xenobiotic exposures to either individual can have an adverse impact on fertility, which is the successful production of children, and fecundity, which is an individual’s or a couple’s capacity to produce children. The role of occupational and environmental exposures in the development of infertility is difficult to define.12,42,88 Well-designed and conclusive epidemiologic studies are lacking because of the following factors: laboratory tests used to evaluate fertility are relatively unreliable, clinical endpoints are unclear, xenobiotic exposure is difficult to monitor, and indicators of biologic effects are imprecise. Although the negative impact of xenobiotics on fertility is often ignored, infertility evaluations are incomplete without a thorough xenobiotic exposure and occupational history. Differences in the toxicity of xenobiotics in individuals are sex related, age related, or both. Xenobiotic-related, primary infertility is the result of effects on the hypothalamic–pituitary–gonadal axis or a direct toxic effect on the gonads.76 Fertility is also affected by exposures that cause abnormal sexual performance. Table 19–1 lists xenobiotics associated with infertility.
TABLE 19–1Xenobiotics Associated with Infertility ||Download (.pdf) TABLE 19–1 Xenobiotics Associated with Infertility
|↓ LH, oligospermia
|↓ Testosterone production
|Chromosomal aberrations in sperm
|↓ FSH, ↓ LH, ↓ spermatogenesis
Combination chemotherapy (CVP, MOPP, MVPP)
|↓ Testosterone production, Leydig cell damage, asthenospermia, oligospermia, teratospermia
|Asthenospermia (in monkeys), oligospermia
|Azoospermia, oligospermia, testicular atrophy
|↓ Spermatogenesis, asthenospermia, teratospermia
|↓ LH, ↓ testosterone
|↓ Sperm motility
| Combination chemotherapy
|Spontaneous abortions, still births
|Affect hypothalamic–pituitary axis, end-organ resistance to hormones, amenorrhea
Aphrodisiacs are used to heighten sexual desire and to counteract sexual dysfunction. Humans have long sought the perfect aphrodisiac. However, of those tried, their effectiveness is variable, and toxic consequences occur commonly. Particularly popular are the various treatments for male sexual dysfunction, or erectile dysfunction.
Although many people search for a cure for impotence or infertility, others explore xenobiotics that can be used as abortifacients. Routes of administration used include oral, parenteral, and intravaginal, with an end result of pregnancy termination. However, many of these xenobiotics produce systemic toxic effects on the mother and a nonaborted fetus.
This chapter examines these issues, ...