About Occupational Exposure & Infertility
Effects of occupational exposure on the reproductive system of men and women may become manifest as alterations in sex hormone levels, diminished libido and potency, menstrual disorders, premature menopause, delayed menarche, ovarian dysfunction, impairment of semen quality, and reduced male and female fertility. Toxic exposures can cause direct cell damage in the developing sperm and eggs. Maternal exposure during pregnancy may disturb fetal development by either directly or indirectly interfering with maternal, placental, or fetal membrane functions.
Toxic exposures can induce many wide-ranging effects, e.g. foetal death, intrauterine growth retardation, preterm birth, birth defect, postnatal death, disturbances in cognitive development, and changes in immunological sensitivity, or childhood cancer.
The mother's exposure at work to chemicals may also cause contamination of her breast milk.Some chemicals with hormonal activity, so-called endocrine disrupters, may alter the function of the endocrine system and consequently cause adverse reproductive effects, e.g. poor semen quality and damaged reproductive tissues in men and some gynaecological medical conditions in women (endometriosis, benign noncancerous tumors and infections of reproductive organs). Many chemicals, such as polychlorinated organic compounds, pesticides, phthalates, bisphenol A, brominated flame retardants and heavy metals have been identified as being possible endocrine disrupters.
Difference in the timing, duration and dose of exposure may lead to different outcomes.
Miscarriage or birth defects are the principal outcomes if exposure has occurred during the first trimester of pregnancy. Exposure later in pregnancy is more likely to shorten the duration of gestation, reduce birth weight and affect the development of the brain. A lower dose of a toxicant may cause birth defects, whereas a high dose may produce miscarriage or infertility.
Adverse effects on reproduction and development are often the result of exposure during the narrow, vulnerable periods of ovulation, formation of a mature sperm (spermatogenesis) and the formation of organs within the embryo (foetal organogenesis). Some effects may not become evident for years. For example, lead may gradually accumulate in maternal tissue only to be released during pregnancy or lactation. Some toxicants, such as antineoplastic agents (cancer chemotherapy drugs), may reduce the number of female germ cells, leading to a shortened reproductive life span.