Women who have had chemotherapy may not only damage their own fertility but that of their children as well, research suggests.
As The Daily Mail reports, it has long been known that chemotherapy can wreak havoc on people’s ability to have children.
For this reason, women and men are encouraged to freeze their eggs or sperm before treatment.
But when chemotherapy patients have children naturally, it was usually assumed that their ability to reproduce was unaffected.
What has surprised researchers is that children born to women who have had chemotherapy have 72 per cent fewer children of their own than members of the general population.
The effect seems to mainly affect women.
Children of men who had chemo treatment went on to have a similar number of children to members of the general population of the same age.
Researchers based at the University of Utah in Salt Lake City used data from the Utah Population Database to conduct two studies that tested whether receiving chemotherapy was damaging to the fertility of children of chemotherapy patients.
The research was presented to the American Society for Reproductive Medicine in San Antonio.
Daughters of women who had chemotherapy had 71 per cent fewer children than the general population. Sons of female chemo patients had 87 per cent fewer children.
While the effect appears highly dramatic, the researchers point out that studies need to be carried out on larger populations – so the findings are highly preliminary.
Lead researcher Dr Biren Patel said: ‘This is an archival study with a young population. There might be an effect but we plan to repeat this study in 10 years when our study population is 29 and further along in their reproductive years.
‘They are only 19 years old right now. It is important to not over-call the results yet. More work needs to be done.
‘We only had five individuals with children out of 132 so we have a very low sample size which definitely swings the statistics wildly.’
The mechanism of how fertility can be damaged between generations is not known.
Researchers suspect it may be caused by epigenetics – or changes which can be compared to switches that turn on or off certain genes in the DNA passed on to a person’s offspring.
Recent studies have found that smoking, for instance, causes epigenetic changes in a person’s DNA.
In conclusion, the scientists said: ‘Chemotherapy given to women may have intergenerational effects on fertility. Further research should evaluate the germ line and gametes of children born to mothers exposed to chemotherapy for genetic and epigenetic changes.’
Daniel Williams, MD, President of the Society for Male Reproduction and Urology, commented, ‘These two studies highlight the importance of offering pre-chemotherapy fertility preservation services to all reproductive age cancer patients who want to have children and grandchildren in their future.
‘Although the studies do not distinguish between different types of cancer and different chemotherapy regimens, it strongly suggests that the impact of chemotherapy may be greater on eggs than on sperm.’
In the UK, NICE guidelines recommend all women get the option to freeze their eggs before chemo treatment – in case chemo leaves them infertile.
However, many clinical commissioning groups do not offer the service.