Children exposed to severe maternal stress during pregnancy are nearly ten times more likely to develop a personality disorder (PD) by age 30, when compared with those whose mothers experience no stress during pregnancy, the first ever study of its kind has found.
It also found that mums-to-be experiencing moderate stress during gestation are nearly four times more likely to have children who develop a PD.
The research published in the British Journal of Psychiatry is the first to provide evidence of an association between prenatal stress and PD.
The findings suggest a greater need to support the emotional well-being and mental health of women and families during pregnancy.
The authors suggest that prenatal stress could impact development of the child during pregnancy as well as carry over to the family environment and parent-child relationships after birth, both of which could increase the risk of PD.
Dr Trudi Seneviratne, chair of the perinatal faculty at the Royal College of Psychiatrists, said: “Pregnancy can be a stressful time and this study shows the importance of ensuring mums-to-be have access to the mental health support they need.
“NHS England has dramatically improved access to perinatal mental health services in recent times and these findings show how important it is for NHSE to continue investing in this area.
“The study does not account for important factors that affect stress and child development - such as financial situation, parenting style and sexual trauma - which we know contribute to the development of severe mental illness, including personality disorders.”
The longitudinal study – which gathered data for the same subjects over a period of time - used birth statistics from the Helsinki area between 1st July 1975 and 30th June 1976.
The sample of 3,626 children had mothers who completed regular health and well-being assessments during pregnancy. Each month they answered a question on mental stress since their last visit, indicating if they had no stress, some stress or notable stress.
Ross Brannigan, lead author from the Royal College of Surgeons in Ireland, said: "This study highlights the importance of providing mental health and stress support to both pregnant women and families during the antenatal and postnatal period.
“It is also important to note that the study shows an association between stress during pregnancy and the development of personality disorders. More research is necessary to prove a causal relationship."
PD diagnosis data was obtained through the Finnish Hospital Discharge Register and the Finnish National Population Register in 2005, at which point the sample members would have been around 30 years old.
40 of the 3,626 sample had a PD and after accounting for variables including parental psychiatric history, maternal smoking during pregnancy and subjective feelings of depression, the authors found children exposed to maternal stress were 9.53 times more likely to develop a PD, when compared to whose mothers experienced no stress during pregnancy.
Those whose mother experienced moderate stress were 3.59 times more likely.
Previous studies have found brain differences between those with and without personality disorders, and that prenatal stress impacts childhood brain development
It is also likely that women who are stressed during the antenatal period will also be stressed during the postnatal period, which could impact the parent/child relationship.
It is thought than 1 in 20 people in the UK have a PD[i] which can lead to psychosocial impairment, increased rates of suicide, functional impairment and increased long-term use of health services.