Maternal anxiety and infants' hippocampal development: timing matters

A Qiu,M J Meaney,M V Fortier,H Chen,P D Gluckman,A Rifkin-Graboi,Y-S Chong,K Kwek

doi:10.1038/tp.2013.79

Abstract

Exposure to maternal anxiety predicts offspring brain development. However, because children's brains are commonly assessed years after birth, the timing of such maternal influences in humans is unclear. This study aimed to examine the consequences of antenatal and postnatal exposure to maternal anxiety upon early infant development of the hippocampus, a key structure for stress regulation. A total of 175 neonates underwent magnetic resonance imaging (MRI) at birth and among them 35 had repeated scans at 6 months of age. Maternal anxiety was assessed using the State-Trait Anxiety Inventory (STAI) at week 26 of pregnancy and 3 months after delivery. Regression analyses showed that antenatal maternal anxiety did not influence bilateral hippocampal volume at birth. However, children of mothers reporting increased anxiety during pregnancy showed slower growth of both the left and right hippocampus over the first 6 months of life. This effect of antenatal maternal anxiety upon right hippocampal growth became statistically stronger when controlling for postnatal maternal anxiety. Furthermore, a strong positive association between postnatal maternal anxiety and right hippocampal growth was detected, whereas a strong negative association between postnatal maternal anxiety and the left hippocampal volume at 6 months of life was found. Hence, the postnatal growth of bilateral hippocampi shows distinct responses to postnatal maternal anxiety. The size of the left hippocampus during early development is likely to reflect the influence of the exposure to perinatal maternal anxiety, whereas right hippocampal growth is constrained by antenatal maternal anxiety, but enhanced in response to increased postnatal maternal anxiety.

Highlights

Anxiety has a familial component[1] such that children of affected parents show a significantly increased risk for emotional problems.[2,3] the precise mechanism through which vulnerability is transmitted remains unclear, there is evidence that maternal emotional well being influences the offspring
We found that antenatal maternal anxiety did not influence bilateral hippocampal volume at birth
The short form children of mothers reporting increased anxiety during pregnancy of the 5HTTLPR serotonin promoter is associated with the showed slower growth of both the left and the right hippocampus presence of anxiety disorders

Summary

Introduction

Anxiety has a familial component[1] such that children of affected parents show a significantly increased risk for emotional problems.[2,3] the precise mechanism through which vulnerability is transmitted remains unclear, there is evidence that maternal emotional well being influences the offspring. Effective treatment of depression of mothers of children 7–17 years of age decreases psychological problems in the offspring suggesting effects on parent–child interactions.[7] mood disorders promote forms of parenting[8,9] that enhance stress reactivity, social withdrawal and inattention,[10,11,12,13] which in turn predict an increased risk for mood disorders. Several development models suggest that early exposure to stress may confer resistance to stressors in later life. Existing studies on the consequences of maternal anxiety are compromised by the fact that the relevant outcome measures, including imaging studies of neural endophenotypes, have been collected in later childhood and are confounded by unknown postnatal influences

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