A UK bioethicist has argued that 18-year-old men should consider freezing their sperm to reduce the risk of their children having genetic disorders.
While men are generally able to conceive at an older age than women, Dr Smith is of the view that freezing should be considered for sperm to avoid the risk of 'gradually reducing human fitness in the long term'.
There has been a trend among both men and women to have children later in life and the average age of fatherhood in England and Wales has increased to 33, from 31 in the early 1990s. As men age, sperm become more prone to errors, which has been linked to an increased risk of conditions such as autism and schizophrenia.
Writing in the Journal of Medical Ethics, Dr Smith suggests, 'If demographic trends towards later fatherhood continue, this will likely lead to more children suffering from genetic disorders.'
Dr Smith argues that even small increases in the risk of disease could have a significant effect when scaled up across a whole nation and that the question of paternal age is of 'ethical importance'. In order to avoid these risks, he encourages the idea of 'state-supported universal sperm-banking', which he thinks would be more effective than encouraging men to become fathers younger.
Dr Smith suggests that 18 is the ideal age for men to freeze their sperm. He said there was no fixed age when someone could become an 'older dad' but that people in their 40s might want to use sperm frozen when they were younger.
However, the British Fertility Society (BFS) has called such a move 'a very artificial approach to procreation'.
Professor Adam Balen, chair of the BFS said, 'Not only does it provide a very artificial approach to procreation, but also a false sense of security as the technology does not guarantee a baby.'
Professor Balen suggests that, instead, a societal shift and extra support for young couples to work and have children earlier is required. Speaking to BBC News, he suggested we should look to the example of Scandinavian countries in terms of policies and attitudes towards parenthood issues, including paternity leave.
Sheena Lewis, chair of the British Andrology Society, agrees: 'We need to get the message across that it's really a much better idea for men as well as women to have their children in their 20s and 30s.'