Long-term effects in progeny of paternal environment and of gamete/embryo cryopreservation.
In addition to gross malformations, many problems relating to the formation of gametes and embryos can generate, within a continuum of abnormalities, a number of problems that are less evident. On the basis of genetic and/or biochemical or cytological changes, these effects generally appear long after birth as functional difficulties that range from growth changes and altered endocrine functions and cancer to very late behavioural disorders. Such problems may have effects on males and females before conception, on the embryo during gestation, and may also impact on the success of assisted reproduction techniques. For this reason, we have examined the experimental and clinical data that indicate the long-term consequences, for progeny, of iatrogenic and toxic environmental factors on the male reproductive system, and in particular the effect that one specific condition-cryopreservation-may have on gametes and the conceptus. We then focus on the interpretation given to these data which, in general, emphasize the need not only for further experiments to help understand the mechanism of anomalies and increase the level of vigilance in humans, but also to extend follow-up investigations in children.