In the journal Translational Psychiatry, German researchers reported that babies born to stressed mothers are more likely to be prone to stress themselves. Genetic changes that occur in the fetus because of the mother’s stress are the main causes for such susceptibility to stress.
Helen Gunter, PhD, and team of the University of Konstanz established that an altered gene expression associated with behavioral problems and stress response was observed in adolescents whose mothers were subjected to domestic violence while pregnant. The authors believe that this alteration in gene expression continues right into adulthood.
This implies that a stress hormone receptor undergoes a biological change if the pregnant mother is subjected to extreme stress while the baby is still in the womb as also observed during intimate partner violence. This change may subsequently affect the child’s ability to deal with stress and make it difficult handle stress.
This is the first study that correlates pregnancy related stress with alterations in DNA methylation, a process by which genes are switched off and on. The study elucidates how prenatal stressors affect the mental state of a person throughout their lives.
The scientists gathered information on intimate partner violence in this study comprising 25 children aged 10 to 19 years and their mothers. Violence was experienced by 8 of the mothers during their pregnancies.
The authors explained that a large number of pregnant women are not exposed to similar persistent levels of stress like the females of this study who did not have characteristic home circumstances.
Regulation of gene expression involves Methylation, and Methylation status of the offspring was determined at adolescence. Focus was laid on the stress-response-mediating glucocorticoid receptor (GR) gene. Alterations in methylation of the GR promoter were observed in fetuses of mothers who were exposed to intimate partner violence during pregnancy which established their inferior ability to handle stress.
“It would appear that babies who get signals from their mum that they are being born into a dangerous world are faster responders. They have a lower threshold for stress and seem to be more sensitive to it,” said one of the lead researchers, Professor Thomas Elbert.
“For the first time, we show that methylation status of the GR gene of adolescent children is influenced by their mother’s experience of IPV (intimate partner violence) during pregnancy,” wrote the authors.
They added that a potential mechanism by which prenatal stress impacts psychological function through methylation of the GR promoter could be established through the findings of the study.
The researchers were of the opinion that further studies are required in order to determine whether these alterations influence the coping skills of children.
“As these sustained epigenetic modifications are established in utero, we consider this to be a plausible mechanism by which prenatal stress may program adult psychosocial function,” concluded the authors.
“Transgenerational impact of intimate partner violence on methylation in the promoter of the glucocorticoid receptor”
K M Radtke1,2,4, M Ruf1,4, H M Gunter2,3,4, K Dohrmann1, M Schauer1, A Meyer2 and T Elbert
Translational Psychiatry (2011) 1, e21; doi:10.1038/tp.2011.21