New research shows that women who are stressed during pregnancy are more likely to give birth to children with personality disorder.
These children are 10 times more likely to develop, often in their 30s.
The rate is four times more likely to occur in children whose mothers suffered moderate stress during pregnancy.
Experts believe that the reason for this is that stress during pregnancy, with high levels of cortisol affects the development of the child's brain.
Personality disorders involve a wide range of behavioral problems with turbulent thinking, impulsive behavior and aggression.
"This study highlights the importance of providing mental health support and avoiding stress in pregnant women during the antenatal and postnatal period," said study leader Ross Branigan of the Royal College of Surgeons in Ireland.
Parental psychological history and smoking are taken into account, both of which affect levels of personality disorder.