Reproductive toxicity is a hazard associated with some chemical substances, that they will interfere in some way with normal reproduction; such substances are called reprotoxic. It includes adverse effects on sexual function and fertility in adult males and females, as well as developmental toxicity in the offspring. It is usual to take a practical definition, including several different effects which are unrelated to each other except in their outcome of lowered effective fertility. The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) separates reproductive toxicity from germ cell mutagenicity and carcinogenicity, even though both these hazards may also affect fertility.
One well known group of substances which are toxic for reproduction are teratogens – substances which cause birth defects – of which (S)-thalidomide is possibly the most notorious. Another group of substances which has received much attention (and some controversy) as possibly toxic for reproduction are the so-called endocrine disruptors. However, many substances which are toxic for reproduction do not fall into either of these groups: lead compounds, for example, are considered to be toxic for reproduction given their adverse effects on the normal intellectual and psychomotor development of human babies and children.
Many drugs have effects on the human reproductive system: these may be desired (hormonal contraception), a minor unwanted side effect (many antidepressants) or a major public health problem (thalidomide). However, most studies of reproductive toxicity has focussed on occupational or environmental exposure to chemicals and their effects on reproduction. It may be noted that both consumption of alcohol and tobacco smoking are known to be "toxic for reproduction" in the sense that the term is used here.
Bisphenol A (BPA) is an example of an endocrine disruptor which negatively affects reproductive development. BPA is a known as estrogen mimicker (Xenoestrogen) and a likely androgen mimicker, which is used in the production of various plastic products. BPA exposure in fetal female rats lead to mammary gland morphogenesis, increased formation of ovarian tumors, and increased risk of developing mammary gland neoplasia in adult life. Additionally, BPA affects male fertility by resulting in lower sperm quality quality and sex function. The toxicological impact of BPA is better understood and studies in females than in males.