Assisted reproduction, cancer risk for those born with these techniques?

There are 90 million couples in the world with fertility problems, 25 million in Europe alone. And, now more than 4 decades after the birth of the English Louise Brown, the first child born in a test tube, the children who have come into the world thanks to assisted reproduction techniques, or Pma, are 8 million: a very long line of parents and children who quite simply, they are thanks to science.

Pma and greater risk of cancer of the newborns

According to a cohort study published in September in the journal Jama Network Open children conceived with PMA would have a greater risk of getting cancer in pediatric age than those conceived naturally, and the increase would concern mainly, but not only, cases of leukemia and liver tumors.

A conclusion that the Taiwanese researchers authors of the work reached by analyzing with a follow-up of 6 years the data collected from 2004 to 2017 of more than two million and 300 thousand parent-child triads, a number that included couples who had conceived naturally, and infertile or subfertile couples who had resorted to PMA (for sample details, the title of the study is Assisted Reproductive Technology and Risk of Childhood Cancers).

Frequency attributable to chance

“Colleagues from Taiwan – he reasons Filippo Maria Ubaldipresident of Sifes-MR, Italian Society of Fertility and Sterility and Reproductive Medicine and member of the table for research and training in the prevention and treatment of infertility of the Ministry of Health – they found very low numbers, we are in the order of 12 cancer cases out of 10,000 (in percentage terms we are 0.00012%) born from spontaneous conception, compared to 20 out of 10,000 (0.0002%) born from PMA: we are talking about 8 more cancer cases per 10,000 births, an absolutely attributable to chance “.

There is no cause-effect relationship

“Attributable to chance” is like saying that with such small percentages, even if the processing of the numbers resulted in statistical significance, that is, if, as they say, the data were ‘statistically significant’, its power, or the power of the data , is in any case very low. “This is exactly the case – confirms the expert – the presence of statistical significance does not imply that there is a cause-effect relationship between PMA and pediatric oncological disease. Just think of the very high number of confounding factors that can come into play in studies like this one. we are talking about, that is, of those elements that have nothing to do with assisted procreation techniques, but which can in any case influence the final data “. Possible confounding factors are for example the same cause of infertility of parents who use PMA, their genetic background, that is the predisposition to an increased risk of developing neoplastic diseases in the course of life, “such as positivity to BRCA gene mutations – resumes to explain Ubaldi – and to these must be added the possible exposure to polluting or harmful factors present in the environment of adults, before, during or after gestation, and the environmental exposure of the children themselves, as well as their own genetic background “.

Over the years, many studies

The study on Jama network open it’s not the first and certainly won’t be the last of its kind. And rightly so, because in addition to being a strictly medical issue, the possible association between PMA and pediatric oncological disease is a topic that touches essential chords: in human, emotional and anthropological terms. “And in fact, over the years there have been many works that have had the aim of investigating this hypothetical link. There is one from 2019, published by Dutch oncologists in the journal Human Reproduction who observed a group of over 47 thousand children, 24 thousand of whom were born with PMA – continues Ubaldi – and who seemed to have provided solid data on the issue: among other things, echoing a series of other previous studies, the authors concluded that no ‘there is no association between assisted reproductive techniques and a general increase in the risk of cancer in children. “In the study referred to by the expert, the frequency of oncological diagnoses was in fact the same regardless of the group they belong to, and at the end of a follow-up that lasted over 20 years.

Monitoring studies welcome

The follow up, the monitoring over time of those born in the test tube is fundamental and must certainly be encouraged, “all the studies that monitor the health of people who have come into the world thanks to laboratory techniques are welcome, but so that they produce data controlled and solid – concludes the expert – to avoid alarmism, fears, towards technologies that sometimes represent the only hope of conception for infertile couples “.