Researchers have found that depression and anxiety in moms-to-be is linked to a heightened risk of asthma and poorer lung function in their 10-year-old children.
The findings, published in the journal Thorax, suggest that the risk of later life respiratory disease is likely programmed in the womb, rather than necessarily influenced by as yet unmeasured genetic, social or environmental factors.
Psychological distress, to include anxiety and depression, during pregnancy is associated with increased risks of respiratory disease in preschoolers, but whether this association persists into later childhood isn't known.
To find out, the researchers from Erasmus University Medical Centre in the Netherlands, drew on participants in the Generation R Study, a population-based prospective cohort study, which has been tracking life from early pregnancy onwards in Rotterdam.
The degree of overall psychological distress, depression and anxiety experienced by each parent in the second term of pregnancy and three years after the birth, was assessed, using a validated 53-item questionnaire.
Depression and anxiety were assessed only in the mothers, at two and six months after birth.
In all, 362 (nearly nine per cent) of the mothers and 167 (just under four per cent) of the fathers were clinically depressed and/or anxious during the pregnancy.
The lung function of 3,757 of the offspring was measured when they were 10 years old, and information on asthma obtained in 3,640 of them. Almost six per cent had asthma.
Mothers' overall psychological distress and symptoms of anxiety and depression during pregnancy were all associated with a 45-92 per cent increased risk of current asthma in their children, after adjusting for potentially influential factors, such as age, ethnicity, smoking during pregnancy, and pet keeping.
Factoring in fathers' psychological distress during pregnancy didn't change this association.
Further analysis of the patterns of psychological distress showed that mostly depressive or anxiety symptoms both during and after pregnancy were associated with a heightened risk of asthma in the children.
But separating out the potentially influential factors into three different groups, including lifestyle and health-related, socioeconomic, and birth and early childhood factors, made no difference to the associations found.
"Our results may indicate an intrauterine effect of maternal psychological distress during pregnancy on foetal lung development and respiratory morbidity, rather than an effect of unmeasured genetic, social, behavioural or environmental factors," the authors wrote.