Stress in pregnancy can increase anxiety in female babies

High maternal levels of the stress hormone cortisol during pregnancy increase the prevalence of anxious and depressive-like behaviour in female offspring assessed at the age of two.  This is the finding of a new study in the journal Biological Psychiatry.


Effects of cortisol on the developing brain

The effect of elevated maternal cortisol appeared to result from stronger communication between brain regions involved in sensory and emotion processing.  But this effect was seen only in female offspring and not in boys.

Over the last two decades, studies have demonstrated the importance of the environment in the womb in health and disease in later life.  Programming of the brain is not gene-centred but critically dependent on conditions during pregnancy and in early postnatal life.  

The findings of this new study show again the role of prenatal conditions in developing later susceptibility to mental health problems in offspring.   It also demonstrates a specific risk factor for females.

John Krystal, editor of Biological Psychiatry says
Many mood and anxiety disorders are approximately twice as common in females as in males. This paper highlights one unexpected sex-specific risk factor for mood and anxiety disorders in females
High maternal levels of cortisol during pregnancy appear to contribute to risk in females, but not males.

To estimate the overall cortisol level during pregnancy, senior author Claudia Buss, PhD, of Charité University Medicine Berlin and the University of California, Irvine and colleagues measured cortisol levels over multiple days in early-, mid-, and late-pregnancy. Measurements taken from the 70 mothers included in the study reflected typical variation in maternal cortisol levels. 

Brain imaging in early postnatal development

The researchers then used brain imaging to examine connectivity in the babies soon after birth, before the external environment had begun shaping brain development, and measured infant anxious and depressive-like behaviours at 2 years of age.  Dr Buss says
Higher maternal cortisol during pregnancy was linked to alterations in the newborns’ functional brain connectivity, affecting how different brain regions can communicate with each other.
The altered connectivity involved a brain region important for emotion processing, the amygdala. This pattern of brain connectivity was predictive of anxious and depressive-like symptoms two years later.

The environment in the womb influences brain connectivity

The authors say the findings reveal a potential pathway through which the environment in the womb may predispose females to develop mood disorders. The study supports the idea that maternal stress may alter brain connectivity in the developing fetus, programming vulnerability for developing a mood disorder after birth and in later life.

Comments

Popular Posts