An IVF birth more than doubles the likelihood of a child developing asthma, research has shown.
In the most extreme cases the risk is increased almost five times, according to new study findings.
Children conceived with artificial help are also more likely to wheeze or take anti-asthmatic medicines by the age of five.
Scientists discovered the link after analysing data on 18,818 children from across the UK born between 2000 and 2002.
But they point out that the association may not be causal, and the chances of a child conceived after IVF treatment becoming asthmatic are still slim.
Researchers conducting the UK Millennium Cohort Study compared children in different groups with those born after natural planned pregnancies.
Children born to sub-fertile parents were 39 per cent more likely to be experiencing asthma symptoms by the age of five and 27 per cent more likely to wheeze.
Closer study showed that the association was mainly driven by children conceived via some form of assisted reproduction technology (ART). This includes IVF (in-vitro fertilisation) and ICSI (intra-cytoplasmic sperm injection) which involves injecting sperm directly into eggs.
However, only 104 children fell into this category, leading the scientists to urge caution when interpreting the results.
The findings are published in the journal Human Reproduction.