The scope of environmental impact on reproduction is very large. It aims at covering all aspects of reproductive problems and their links to the environment. Therefore, it deals with female and male reproductive impairments, whatever their severity and their sites, gonad or extra-gonad. For women, effects include direct lesions of the oocyte, with possibilities of chromosomal abnormalities but also malformations of the reproductive tract. Reduced fertility and in some cases total infertility may also result from menstrual irregularities, which can at times include anovulatory cycles. Hormonal changes, even in the absence of menstrual irregularities may also lead to decreased fertility. In addition to congenital malformations, other impairments of the reproductive apparatus may occur, as in the polycystic ovarian syndrome or in endometriosis. Finally one can also include effects during pregnancy leading to spontaneous abortion, preterm delivery still birth or altered sex ratio. Impacts on age at menarche and age at menopause lead to a change in the duration of reproductive life.
