Trauma seems to pass from mother to child
It seems that trauma can be passed on: children born to women affected by post-traumatic stress during pregnancy also seem to be affected. At least, researchers from Denmark, Kosovo and Australia have measured increased levels of the stress hormone cortisol in the blood of such children.
At the same time, they found that genes involved in the development of anxiety and depression, for example, are affected when mothers have been subjected to sexual violence, torture or other traumatic events during pregnancy.
Doctors and practitioners treating torture victims have been seeing this for a long time, but they are pleased that it can now also be demonstrated by biological facts.
The long-term hope is to find a method of ensuring that the children of mothers who have been subjected to traumatic experiences, or who have PTSD, get the proper help right from birth.
One of the researchers behind the study is Line Hjort, PhD, a human biologist from Rigshospitalet and Center for Basic Metabolic Research at Copenhagen University.
The study, the first of its kind in the world, looked at 120 children between the ages of 6 and 17 born to 117 mothers in Kosovo. 72% of the mothers were assessed by questionnaire as having had PTSD while pregnant, while all the women had developed PTSD later. Along with thousands of others, the 117 women had been subjected to sexual violence and torture in the civil war of the 1990s in the former Yugoslavia.
Line Hjort explains that the children were in a constant state of alert, and that this too may increase their risk of developing mental disorders.
Specifically, the study showed that almost 30% of the children had an abnormal (either excessive or insufficient) level of the stress hormone cortisol, something that worries the researchers. ‘Cortisol is a useful hormone because it enables us to react quickly when necessary. But too high a level over an extended period can mean, for example, that we risk ending up in a state of stress or anxiety because we are unnecessarily vigilant and in a constant state of alert’, she says.
A delighted Line Hjort with two of the other researchers, Dr Feride Rushiti and Dr Sebahate Pacolli of KRCT.
Line Hjort emphasises that the study is about women who have been subjected to a very high degree of stress, and that it does not say anything about effects on the unborn child in the womb generally.
She hopes that the study can pave the way for larger-scale investigations of the impact on the child of trauma during pregnancy. The new study is already set to be followed up with another designed to show whether therapy can help these children achieve a lower stress level. The scientists want to find out whether family therapy can be a way of avoiding an elevated cortisol level.
This will be done through a study of the same 120 Kosovan children, who will be examined before and after a course of therapy lasting from 3 to 6 months.
Professor Romain Barrès of the Novo Nordisk Center for Basic Metabolic Research at the University of Copenhagen is one of the leading researchers in the field of epigenetics. In the newspaper Kristeligt Dagblad, he points out that one cannot rule out a connection between the children’s stress and them having been brought up by traumatised mothers. ‘It is possible that the mother’s trauma is affecting the child biologically, but the study includes only a relatively small number of women, so it is important not to come away with overly firm conclusions until we know more. Nor do we know whether it might in some cases be an advantage for children to have a higher blood cortisol content. For example, in some cases it might encourage more careful behaviour’, says Romain Barrès, who – like Line Hjort – calls for further studies.
The study was carried out for: the Kosovo Rehabilitation Centre for Torture Victims (KRCT); Rigshospitalet; the Danish Institute Against Torture; Monash University in Melbourne. The results are published in an article in the scientific journal Epigenomics. First draft submitted: 22 January 2021; accepted for publication: 28 April 2021; published online: 17 May 2021.
Intergenerational effects of maternal post-traumatic stress disorder on offspring epigenetic patterns and cortisol levels | Line Hjort*,‡,1,2, Feride Rushiti‡,3, Shr-Jie Wang‡,4, Peter Fransquet5, Sebahate P Krasniqi3, Selvi I Çarkaxhiu3, Dafina Arifaj3, Vjosa Devaja Xhemaili3, Mimoza Salihu3, Nazmie A Leku3 & Joanne Ryan**,5
The article was published online 17 May 2021.
Department of Obstetrics, Juliane Marie Centre, Rigshospitalet and Environmental Epigenetics Lab, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen.