Background: Maternal prenatal psychological problems may contribute to the development of offspring allergic diseases. We aimed to investigate how maternal mental health disorders one year before and three years after childbirth associate with offspring asthma and asthma phenotypes at 7-12 years.

Methods: Data of children (N=310,701) born in Finland 2001−2006 and their mothers (N=232,240) were collected from registers (Fig 1). Maternal mental health disorder was categorized as any diagnosis from the F00−99 diagnoses based on the International Classification of Diseases (ICD-10) one year before and three years after childbirth. Outcome was the offspring asthma diagnosis (J45, J45.0, J45.1, J45.8, J45.9 and J46.0) at 7-12 years divided into allergic (J45.0) and non-allergic (J45.1) asthma.

Results: Of the mothers, 14,362/6.2% had mental health disorders and of the children, 19,000/6.1% had asthma. Offspring asthma was associated with maternal mental health disorders (adjusted odds ratio 1.24; 95% confidence interval 1.16-1.33), smoking during pregnancy (1.08; 1.03-1.13, respectively), asthma history (2.94; 2.82-3.06), low education of <9 years vs. ≥12 years (1.19; 1.14-1.25) or the child being male (1.47; 1.42-1.52), all p<0.001. The association was stronger between maternal mental health disorders and offspring non-allergic (1.37; 1.18-1.60) than with allergic (1.17; 1.05-1.30) asthma.

Conclusion: Maternal mental health disorders perinatally and in early-life were associated with offspring school-age asthma supporting the theory of intrauterine and early-life programming effect of maternal mental health on the offspring immune system.