How chemotherapy damages fertility of patients’ children

* Offspring of women who have had treatment have 72% fewer babies
* New blood test could predict miscarriage, premature birth, study finds
* Eat fish not oil supplements to build child’s defenses against asthma
* Those with severe difficulties sleeping had 48% chance of conceiving

Women who have had chemotherapy may not only damage their own fertility but that of their children as well, research suggests. 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 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.

Meanwhile, a new blood test could predict from the earliest stage of pregnancy whether a woman will go on to suffer a miscarriage.

The test, carried out in the first 12 weeks of pregnancy, can also predict if a woman is at risk of giving birth prematurely or developing pre-eclampsia, a potentially fatal condition causing high blood pressure.

Researchers discovered molecules in the blood that predict these birth complications with up to 98 per cent accuracy. More research is needed before the test could be rolled out – but the findings have been hailed as ‘very promising’.

Being able to establish if a woman is at risk of such conditions could allow doctors to act early to prevent them. Around one in four women in the UK suffer a miscarriage, while complications including pre-eclampsia and premature birth can cause long-term damage to both mother and baby.

Meanwhile, a new report has found that eating fish is healthier than taking fish oil supplements while pregnant. Eating fish while pregnant might help your children avoid pediatric asthma, a new study has found.

The report published in the Journal of Allergy and Clinical Immunology: In Practice concluded that taking fish oil might do less for your children than eating eight to 12 ounces of fish a week while pregnant.

The researchers compared the effects of the two, which cost about the same, and said that most women are not consuming enough fish while pregnant.

The study’s authors said that doctors need to take this into consideration when making evidence-based recommendations for prenatal care for pregnant women.

While the supplements are considered safe, they can induce the following side effects: indigestion, nausea, rash; loose stools, and bad breath.

Some contraceptive medications can interfere with fish oil supplements’ effects on the body.

The study mentions that the Food and Drug Administration’s recommendation for how much fish pregnant women should consume is the same as the Environmental Protection Agency’s.

It read: “Both organizations joined force to recommend that eight to 12 ounces of low-mercury fish per week be consumed during pregnancy, equal to two to three fish servings per week.”

The researchers said that the mercury levels a woman consumes by eating that much fish while pregnant are not harmful.

In fact, the study’s authors highlighted research that proved the benefits of eating fish while expecting.

“An earlier study demonstrates that the progeny of pregnant women with no fish ingestion are at higher risk to develop asthma and asthma-related admissions and prescriptions when compared with pregnant women consuming fish as in a sandwich or hot meal at least two to three times a week,” the analysis said.

The researchers also asserted that eating fish while pregnant is healthier than taking fish oil supplements. “It is reasonable to hypothesize that enough fish consumption could provide the same benefit as fish oil.”

Additionally, the study said that the cost of eating the recommended amount of fish is comparable to that of taking fish oil supplements. The study’s authors said that the benefits of taking fish oil while pregnant are not clear because the research to back them up is vague.

Meanwhile, research shows failing to get a good night’s sleep may make it harder to have a baby.

Researchers from the Hanabusa clinic in Kobe, Japan, asked 208 women who were having problems getting pregnant to fill in a survey known as the Pittsburgh Sleep Quality index.

This assesses factors including how long they slept for, whether they woke up in the night, their disturbances, use of sleeping pills, their subjective sleep quality and how much alcohol they drank.

Based on the results, the patients were divided into three groups: no sleep difficulties (65 per cent), mild difficulties (26.8 per cent) and severe difficulties (8.2 per cent).

The chance of eggs fertilised in the laboratory successfully growing into embryos was then assessed. The eggs of women with no sleep problems were successfully fertilised 62.9 per cent of the time, falling to 57.1 per cent in those with mild sleep difficulties, and 48.4 per cent in patients with severe difficulties.

The researchers said: “Good sleep patterns can be one of the important daily habits for patients to improve their response to fertility treatments and increase their chances of pregnancy.’

Occasional or moderate alcohol consumption had a positive impact on fertilisation, they found. This may be due to the beneficial effects of a moderate amount of alcohol, such as relieving stress and inducing sleep.

Professor Matthew Walker, of the Sleep Research Centre at Berkeley University in California, who was not involved in the study, said the findings were consistent with other research.

He said: “For example, women sleeping less than six hours per night suffer a 20 per cent reduction in a follicular-releasing hormone – a critical female reproductive element that peaks just prior to ovulation and is necessary for conception.”