Researchers had the parents of 4,231 children fill out well-validated questionnaires on psychological stress in the second trimester of pregnancy, and again three years later. The mothers also completed questionnaires at two and six months after giving birth. The study, in the journal Thorax, found that 362 of the mothers and 167 of the fathers had clinically significant psychological distress during the mothers’ pregnancies.
After controlling for age, smoking during pregnancy, body mass index, a history of asthma and other factors, they found that maternal depression and anxiety during pregnancy was significantly associated with both diagnoses of asthma and poorer lung function in their children. There was no association between childhood asthma and parents’ psychological distress in the years after pregnancy, and no association with paternal psychological stress at any time.
“Of course, this could be only one of many causes of asthma,” said the lead author, Dr. Evelien R. van Meel of Erasmus University in Rotterdam, “but we corrected for many confounders, and we saw the effect only in mothers. This seems to suggest that there’s something going on in the uterus. But this is an observational study, and we can’t say that it’s a causal effect.”