Research published in the BMJ suggests that parental subfertility and assisted reproductive technologies may contribute to increased offspring asthma risk.
Dr Jane Stewart, Chair of British Fertility Society, and Consultant in Reproductive Medicine and Gynaecology, Newcastle Hospitals NHS Foundation Trust, said:
“Whilst this study raises some interesting questions, there are many variables involved in both infertility and the development of asthma. This is an observational study and, as the authors state, a direct link cannot be shown between infertility, assisted reproduction and asthma. Much more investigation would be required to establish any causal link.”
Mr Mark Wilcox, Clinical Director, CARE Fertility, said:
“This is an interesting observational study which means that it’s not possible to answer whether any connection is causative or not. Further research is required, but in the meantime changing the way treatments are offered is not indicated”
Prof. Alastair Sutcliffe, Professor of General Paediatrics, University College London, said:
“This study attempts to address a suggestion by previous researchers that asthma is more common amongst children conceived with fertility treatments. Like others it uses registry data and therefore cannot prove a true effect.
“Although the press release headlines the numbers in both registries, one of which only had a 42% (highly unrepresentative) participation rate the real numbers of children investigated were only 9,000 (app.) conceived using fertility treatments.
“Furthermore the study did not have access to key confounders such as paternal smoking rates.
“It is well established that families who have an Assisted conceived child are more likely to take them to health care facilities, a form of bias acknowledged by the authors in their discussion, but not in the press release.
“Their proposed mechanistic link between asthma and assisted conceived is oblique and in my view implausible.
“But as per seemingly anything published to suggest ill health in children conceived after assisted conception, it gets accepted by high ranked journals.
“This study needs to be considered as largely speculative and unconvincing.
“The rates of ‘asthma‘ were implausibly low and this suggests a fault in how it was defined. Just because a child has had a couple of treatments for broncho-constriction does not suggest they have a major asthma problem.
“In the real world the effects we see from assisted conception that really matter are such as the risks of the births of premature babies, and the risks associated with low birth weight or higher order births (3, 4, or more)
“These are what matter in the real world.”
‘Maternal history of miscarriages and measures of fertility in relation to childhood asthma’ by Magnus et al. was published in BMJ at 23:20 UK time on Tuesday 4th December.
Professor Sutcliffe: “Is funded by the MRC investigating health effects of fertility treatment and is studying 88,000 ART conceived children compared with millions of UK children, his findings are unlikely to concur with this small Norwegian study.”
None others received