Autism may be linked to parents' infertility, rather than to IVF

IVF treatment was not associated with an increased risk of autism in children, according to a new study.

The large-scale study from ECHO (the Environmental influences on Child Health Outcomes Program from the US National Institutes of Health) found no association between either IVF or non-IVF fertility treatments and an increased risk of autism in resulting children.

'This study contributes to the growing body of evidence indicating that infertility treatment itself is not independently associated with child neurodevelopment outcomes,' said Dr Linda Khan from the New York University School of Medicine, lead author of the study published in JAMA Network. 'Rather, it appears that the parents' underlying fertility problems – whether stemming from genetic, environmental, or other influences – are likely driving these associations.'

The study used a dataset of 15,382 mother-child pairs from 44 research locations across the USA, including Puerto Rico. Analysis showed no association between fertility treatments and autism, but found that children of parents who struggled to conceive had a higher risk for autism-like traits and behaviours even when conceived naturally.

However, it did find an association between children conceived using non-IVF fertility treatments and a higher risk of attention deficit hyperactivity disorder (ADHD). The authors suggest that this observation might be due to confounding factors such as the impact of a parent with PMOS (polyendocrine metabolic ovarian syndrome, previously PCOS), although this requires more research.

'We suspect that this finding reflects confounding by indication – specifically, PCOS. PCOS has been linked to a range of child cognitive and behavioural outcomes, but particularly ADHD,' wrote the authors. 'Indeed, among the four exposure groups included in our analysis, the highest prevalences of PCOS were in the non-IVF (49 percent) and IVF (31 percent) treatment groups, while only 11 percent of mothers who conceived naturally with subfecundity and three percent of mothers who conceived naturally without subfecundity had PCOS.'

There have been numerous previous studies into whether fertility treatments cause neurodevelopmental variations. While most have found no association between the two, these previous studies have largely been on small cohorts with limited follow-up. This made it difficult to separate the effects of fertility treatment from the result of reduced fertility, in the way this study has done.

Neuroscience News called the study a 'vindication for IVF protocols' and that the lack of association between IVF and neurodevelopmental variations should 'provid[e] reassurance to millions of families utilising advanced reproductive technologies.'