Using artificial reproductive techniques has allowed many parents who are unable to conceive naturally to have their own children. But it now seems that for one of the most common forms of in vitro fertilization (IVF), fathers may be passing their fertility problems on to their sons.
Researchers have found that men born using the intra-cytoplasmic sperm injection (ICSI) technique, in which sperm is injected directly into the egg, and then implanted into the womb, also have fertility issues.
There had been previous hints that children conceived through this method of IVF may have future fertility problems, but those earlier studies – such as one looking at the finger lengths of children as a crude assessment of how much testosterone they had been exposed to in the womb – were not particularly rigorous. This latest one, however, has been able to show that those men born via the technique do have lower sperm quality when compared to other men of the same age conceived naturally.
Those men born through ICSI had close to half the concentration of sperm and half as many motile sperm as the other men. They were also found to be more than three times as likely to have sperm concentrations below what the World Health Organization considers to be a “normal” level, which they put at 15 million per milliliter of sperm. This is the first time that researchers have been able to show that the earlier theories of sons inheriting fertility issues from their fathers is actually correct.
“These findings are not unexpected,” Vrije Universiteit Brussels’s Andre Van Steirteghem, who led the research published in the journal Human Reproduction, told The Guardian. “Before ICSI was carried out, prospective parents were informed that it may well be that their sons may have impaired sperm and semen like their fathers. For all the parents this information was not a reason to abstain from ICSI because, as they said: ‘If this happens ICSI can then also be a solution for our sons.’”
Interestingly, the researchers found that the fertility problem experienced by the father was not necessarily the same one the sons suffered from. This suggests that while there is a genetic component to male infertility, there are clearly some less well understood environmental factors playing a role too. These are much more difficult to tease out, and would require further in-depth research.
It is also worth reiterating that this study highlights how fertility treatments such as ICSI are not a way of treating male infertility, simply a method in which to get around it, and effectively leaving it for the following generation to deal with.
