🟠 Moderate Evidence
A comprehensive meta-analysis of nearly 4 million pregnancies has found inconsistent but concerning associations between prenatal exposure to common asthma medications and autism spectrum disorder in children. The study, published in PLOS Medicine, analyzed data from eight studies spanning over two decades to examine whether maternal asthma treatment affects child neurodevelopment.
Key takeaways
- Meta-analysis of 3,867,170 pregnancies shows mixed evidence linking asthma medications to developmental disorders (Shakhshir et al., PLOS Medicine, 2025)
- Beta-2-adrenergic agonists showed potential association with autism spectrum disorder in subset of studies (Shakhshir et al., PLOS Medicine, 2025)
- Researchers emphasize continued asthma treatment remains essential for maternal and fetal health (Shakhshir et al., PLOS Medicine, 2025)
Study at a Glance
| Source | PLOS Medicine |
| Study type | Systematic review and meta-analysis |
| Sample size | N = 3,867,170 |
| Population | Pregnant women with asthma and their children |
| Country | Multiple international studies |
Prenatal Asthma Medication Research Overview
Study designs and participant numbers in meta-analysis, 2003-2025
Source: PLOS Medicine, 2025 | Georgian Medical Journal News
Conflicting Evidence Emerges from Two-Decade Review
The systematic review, led by Lama A. Shakhshir and colleagues, examined studies published between January 2003 and November 2025 following PRISMA guidelines. Of 16,824 initially identified studies, only eight met strict inclusion criteria for investigating prenatal asthma medication exposure and neurodevelopmental outcomes (Shakhshir et al., PLOS Medicine, 2025).
All included studies examined beta-2-adrenergic agonists (B2AA), the most commonly prescribed asthma medications during pregnancy, with one study also investigating inhaled corticosteroids. The research teams used the Newcastle-Ottawa scale to assess study quality and conducted random-effects meta-analyses where appropriate (Shakhshir et al., PLOS Medicine, 2025).
The inconsistent findings highlight the complexity of studying medication safety during pregnancy. While some studies suggested associations with autism spectrum disorder and attention-deficit hyperactivity disorder, others found no significant links, creating uncertainty for clinicians and expectant mothers managing asthma (Shakhshir et al., PLOS Medicine, 2025). For more research developments, see our New Studies section.
Beta-2 Agonists Show Potential Autism Link in Subset Analysis
The meta-analysis of three studies involving 1,380,871 participants indicated significant associations between B2AA exposure and autism spectrum disorder, particularly for both preconception and prenatal exposure windows. However, the study authors noted substantial heterogeneity between studies, with some showing strong associations while others found no effect (Shakhshir et al., PLOS Medicine, 2025).
According to the World Health Organization, autism spectrum disorders affect approximately 1 in 100 children globally. Two studies specifically reported associations with autism spectrum disorder, while one found links to attention-deficit hyperactivity disorder. An updated search identified an additional study examining both conditions plus other neurodevelopmental disorders (Shakhshir et al., PLOS Medicine, 2025).
Clinical Implications Remain Complex for Pregnancy Management
The research underscores a critical clinical dilemma: asthma exacerbations during pregnancy pose well-established risks to both maternal and fetal health, making continued medication essential for most patients (Shakhshir et al., PLOS Medicine, 2025). The study authors noted that uncontrolled asthma during pregnancy has been linked to preterm birth, low birth weight, and increased maternal complications.
Study quality varied across the included research, with designs ranging from large cohort studies to case-control investigations. The American College of Obstetricians and Gynecologists maintains that the benefits of asthma control typically outweigh potential medication risks during pregnancy.
The heterogeneous nature of the findings suggests that individual patient factors, medication timing, dosage, and underlying asthma severity may all influence outcomes (Shakhshir et al., PLOS Medicine, 2025). For clinical guidance updates, visit our Clinical Updates section.
Research Gaps Point to Need for Standardized Studies
The limited number of eligible studies—just eight from over 16,000 screened—reveals significant research gaps in understanding prenatal medication safety. Most studies focused exclusively on beta-2-adrenergic agonists, with minimal investigation of inhaled corticosteroids or combination therapies commonly used in clinical practice (Shakhshir et al., PLOS Medicine, 2025).
The research team, affiliated with the University of Glasgow’s School of Health and Wellbeing, emphasized that study heterogeneity made definitive conclusions difficult. Differences in study populations, medication classifications, outcome definitions, and follow-up periods all contributed to inconsistent findings (Shakhshir et al., PLOS Medicine, 2025).
Meta-analysis of 1,380,871 pregnancies showed significant associations between beta-2-adrenergic agonist exposure and autism spectrum disorder, though substantial heterogeneity between studies limits definitive conclusions
— Lama A. Shakhshir, University of Glasgow (PLOS Medicine, 2025)
What this means
Frequently asked questions
Should pregnant women stop taking asthma medications based on this research?
No, according to the study findings, the benefits of controlling asthma during pregnancy typically outweigh potential risks. Uncontrolled asthma poses established dangers to both mother and baby, while the neurodevelopmental associations remain uncertain and require further study (Shakhshir et al., PLOS Medicine, 2025).
Which asthma medications were studied in this research?
All eight studies examined beta-2-adrenergic agonists, the most common asthma rescue medications, with one study also investigating inhaled corticosteroids. The research did not comprehensively examine all asthma medications used during pregnancy (Shakhshir et al., PLOS Medicine, 2025).
How strong is the evidence linking asthma medications to autism?
The evidence is inconsistent. While some studies showed associations, others found no links, and substantial differences between studies make definitive conclusions difficult (Shakhshir et al., PLOS Medicine, 2025).
The study authors noted that future research must address current limitations through larger, standardized studies that examine multiple medication classes, dosing patterns, and timing of exposure. Until stronger evidence emerges, the established benefits of asthma control during pregnancy continue to support current treatment approaches, with careful monitoring and individualized care remaining essential for optimal outcomes (Shakhshir et al., PLOS Medicine, 2025).
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