Maternal Asthma and the Developing Brain?

Asthma is often seen as a condition of the lungs. But during pregnancy, its reach may extend to the developing brain. A recent meta-analysis now suggests that maternal asthma could be a prenatal risk factor for Autism and ADHD, reshaping how we think about respiratory health in expectant mothers.

The study pulled together the global evidence on whether maternal asthma is linked to increased risks of Autism and ADHD in children. Drawing on multiple observational studies, the authors report a significant association between maternal asthma and higher risk of both conditions. This research asks us to look at asthma not just as a respiratory issue, but as a potential factor in prenatal neurodevelopment.

However, a closer look reveals a crucial question the study couldn't answer: is it the asthma itself, or could something else be at play?

The Link Between Maternal Asthma and ADHD/Autism

Drawing on data from over 5 million mother-child pairs across 12 observational studies, the researchers found that children born to mothers with asthma had significantly increased risks of developing:

• Autism: 36% higher risk (OR = 1.36)
• ADHD: 43% higher risk (OR = 1.43)

These findings were consistent across cohort and case-control studies from diverse regions including the US, Sweden, Taiwan, and Australia, strengthening the likelihood of a genuine link rather than a spurious association.

Sex Differences: A Closer Look

The analysis also revealed notable sex-specific patterns:

• Autism: Male offspring: 28% higher risk (OR = 1.28, p = 0.04). Female offspring: no statistically significant increase (OR = 1.81, p = 0.205, wide CI)

The authors note that this apparent sex difference may reflect under-diagnosis of Autism in girls, who often present differently, or potential protective biological factors.

• ADHD: Males: OR = 1.36 Females: OR = 1.45

Both sexes showed a significant elevation in ADHD risk, with no meaningful difference between them.

The Science Behind The Link – Or Is It?

The authors delve into the science behind the link by exploring biological mechanisms: maternal immune activation, serotonin depletion, neuroinflammation, and microbiome disruption. They also acknowledge shared genetic susceptibility between asthma and ADHD.

But here’s what’s missing: The study does not account for parental neurodivergence, either diagnosed or undiagnosed as a potential confounder.

This is a critical omission. Both ADHD and autism are highly heritable, yet adult women, especially mothers are frequently underdiagnosed. If a mother has undiagnosed neurodivergent traits, they may contribute to her asthma risk and to her child’s neurodevelopmental profile, independent of asthma.

Likewise, paternal neurodivergence is not considered at all, despite its genetic relevance. Without adjusting for parental ADHD or autism, the observed associations may conflate biological inheritance with intrauterine exposure, leading to oversimplified conclusions and potentially misleading risk narratives.

The Implications

It is therefore more important than ever to emphasise: this study demonstrates association, not causation. Having asthma does not mean a child will inevitably develop Autism or ADHD. Maternal asthma may be one of several prenatal risk factors worth monitoring.

In other words, the study highlights an important signal, but without considering parental ADHD as a potential confounder, the strength and direction of the association remain uncertain.

This gap has real-world consequences. It affects how we interpret risk, how we design interventions, and how we support families.

Future studies must integrate parental neurodevelopmental history into their models. This would allow researchers to disentangle:

• The effects of maternal asthma itself
• The influence of parental neurodivergence
• The interaction between immune, genetic, and environmental pathway

Final Thoughts

This research underscores the importance of equitable access to asthma care and developmental screening, particularly in underserved communities where both respiratory and neurodevelopmental conditions may be underdiagnosed.

But it also highlights a broader research challenge: without careful attention to genetic and familial confounders, like parental neurodivergence, we could risk overstating the effects.

Future studies will need to disentangle these threads to clarify how much of the risk is driven by asthma itself versus shared genetic vulnerability.

As research continues to unravel the complex interplay between maternal health and child development, integrated care models will be key to turning insight into impact.

Reference: Zheng, J., Chen, J., Zhang, Q. et al. Association between maternal asthma and ASD/ADHD in offspring: a meta-analysis based on observational studies. npj Prim. Care Respir. Med. 32, 32 (2025). https://doi.org/10.1038/s41533-025-00440-y

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