Teratogens and the male. An analysis with special reference to herbicide exposure.

A review of the experimental evidence and of the human clinical and epidemiological studies relating to possible teratogenesis after exposure of the male to toxic substances is presented. Toxic insults to the process of gametogenesis can occur either in the male or in the female. Temporary infertility can occur in males exposed to toxic substances, and teratospermia is well documented. An increased miscarriage rate among the wives of men chronically exposed to toxic substances has been reported. A number of experiments have been conducted to study the progeny of male mammals poisoned with proven mammalian teratogens. In none of these studies has the teratogenic syndrome (easily demonstrable as an effect of the drug or toxin when ingested by the pregnant mother) appeared in the offspring of a male who has been exposed to the toxin. Epidemiological studies in humans have given no positive evidence that the baseline congenital malformation rate of children is increased if the father has been exposed to toxic substances. The available evidence indicates that spermatogenesis is particularly resilient after exposure to various toxic chemicals.