Human reproduction is a complex process and can be affected in many phases by both host and environmental factors. Many studies have found it difficult to distinguish the occupational causes of congenital malformations from other factors related to parents’ characteristics and their living environment. The extrapolation of results of animal studies to humans is also complicated because there are structural and functional differences between the species, and the mechanisms of harmful effects are seldom known. At present, knowledge on the potential reproductive toxicity of even rather common occupational exposures is limited and only suggestive in many cases.¹ The conception of an embryo involves the fertilisation of the ovum by a spermatozoon. If the ovum and/or spermatozoon is defective, the resulting embryo may die early or late in gestation (resulting in spontaneous abortion or miscarriage). If the defective embryo develops to term, the infant could present with stillbirth or congenital anomalies may be detected at birth or later in life. Another scenario is that the embryo is conceived by a normal ovum and spermatozoon, but in the process of development in the uterus, it is exposed to agents …