New research provides evidence of a significant association between infections during pregnancy and an increased risk of psychiatric symptoms in children, persisting from early childhood to adolescence. This large-scale, longitudinal study, published in the Journal of Child Psychology and Psychiatry, suggests that prenatal exposure to common infections could have lasting impacts on a child’s mental health.
The drive to understand the early origins of psychiatric disorders has led scientists to explore the prenatal environment’s role in child development. The “developmental origins of health and disease” hypothesis suggests that environmental factors during pregnancy can have long-term health consequences. Given the widespread occurrence of infections during pregnancy and their potential to affect the fetus, researchers sought to investigate whether these prenatal infections correlate with psychiatric symptoms in children as they grow.
“Our interest in this topic stems from the growing body of research pointing to a link between prenatal exposure to infections and increased psychiatric risk in offspring,” said study author Charlotte A. M. Cecil, an associate professor of biological psychopathology at the Erasmus Medical Center and the principal investigator of the inDEPTH lab.
“Most studies to date, however, focus on severe infections or clinical diagnoses, often measured only at one time point. As such, we still know little about how exposure to common infections during pregnancy relate to the broader spectrum of child psychiatric symptoms in the general population. Furthermore, it is unclear what the role of timing is in these associations; in other words, does it matter when the infection occurs during pregnancy? And if there are effects on child mental health, are these effects stable over time or do they wane as children get older?”
The research was embedded in the Generation R Study, a large-scale, ongoing research project in Rotterdam, the Netherlands, focusing on the health of mothers and their children from the fetal stage onward. The study spanned from April 2002 to January 2006 and involved a final sample of 3,598 mother-child pairs. The researchers gathered detailed information about maternal infections during each trimester of pregnancy using questionnaires. These infections included common conditions like upper respiratory and gastrointestinal infections.
To assess the children’s psychiatric symptoms, the study used the Child Behavioral Checklist, a reliable and widely recognized tool for evaluating emotional and psychiatric symptoms in children. This checklist was administered at five different age points, ranging from 1.5 to 14 years, allowing the researchers to track the development of psychiatric symptoms over time.
The researchers discovered a positive association between exposure to prenatal infections and an increase in total psychiatric symptoms, internalizing problems (such as emotional issues like depression), and externalizing problems (behavioral issues such as aggression) in children. The study found no significant variation in these effects based on the child’s sex. This association was consistent over time, from early childhood through to adolescence.
“We were surprised to find that the association between prenatal infections and child psychiatric symptoms remained stable over time (from the first mental health assessment at age 1.5 years to the last available assessment at age 14 years),” Cecil told PsyPost. “This suggests that the effect of prenatal infections on neurodevelopmental outcomes may not be transient.”
Interestingly, the study found that infections during any trimester of pregnancy were associated with these increased psychiatric symptoms. However, when each trimester was examined separately, subtle differences emerged. For instance, infections in the first trimester were independently linked to internalizing problems, while second-trimester infections correlated with total and externalizing problems. Despite these variations, the study found that the impact of prenatal infections on psychiatric symptoms did not significantly differ from one trimester to another.
“The lack of significant differences in associations between trimesters was noteworthy, indicating consistent effects of prenatal infection throughout pregnancy,” Cecil said.
The study’s robust methodology allowed for adjustments for a wide range of potential influencing factors, including the child’s genetic liability to psychiatric conditions, chronic maternal illness, birth complications, and childhood infections. Despite these adjustments, the association between prenatal infections and psychiatric symptoms remained significant.
“Our study suggests that exposure to common infections during pregnancy may be a risk factor for child psychiatric symptoms, including emotional and behavioral problems (e.g., anxiety and depression, inattention/hyperactivity and rule-breaking behavior),” Cecil explained. “Importantly, these associations persisted from early toddlerhood into adolescence. Our findings highlight the importance of considering prenatal infections as a potential factor influencing child neurodevelopment and mental health, although more research is needed to establish whether the observed associations are causal and to identify underlying mechanisms.”
But the study, like all research, includes some limitations. “While our study provides new insights on the relationship between prenatal infection exposure and child mental health, our observational design limits us from drawing causal conclusions. For example, it is possible that other factors drive the observed associations (i.e., there is no causal link),” Cecil told PsyPost.
“While we tried to address this possibility by taking into account a wide range of potential external influences (e.g., genetic liabilities, pre-existing maternal health conditions, co-occurring prenatal exposures, birth complications, childhood infections, etc.), our findings could still reflect in part unmeasured confounding. Further research using advanced causal inference methods is needed to assess causal relationships between prenatal infections and child psychiatric symptoms.
“This is particularly important given that the research involves pregnant women, and public health policies need to carefully balance the pros and cons of new preventive measures within this vulnerable group,” Cecil said. “Future research will also be needed to identify potential factors that mitigate the effects of prenatal infection on offspring mental health, which could be targeted to enhance resilience in exposed offspring.”
This study sheds light on a vital aspect of prenatal care and child development. Its findings underscore the importance of monitoring and managing infections during pregnancy, not just for the immediate health of the mother and child, but also for the long-term mental wellbeing of the child.
“Our study highlights the importance of considering prenatal factors for understanding child mental health,” Cecil explained. “While avoiding infections entirely during pregnancy is likely not feasible, public health measures aimed at lowering overall infection risk may be beneficial (e.g., social distancing and wearing facemasks), although potential drawbacks of these strategies also need to be carefully considered (e.g. social restrictions). Furthermore, our findings suggest the potential relevance of incorporating information about prenatal exposures, such as infections, into clinical assessments, providing a more comprehensive understanding of the child’s developmental history in clinical mental health care.”
The study, “Exposure to prenatal infection and the development of internalizing and externalizing problems in children: a longitudinal population-based study“, was authored by Anna Suleri, Anna-Sophie Rommel, Alexander Neumann, Mannan Luo, Manon Hillegers, Lotje de Witte, Veerle Bergink, and Charlotte A. M. Cecil.
