When they were 18 weeks pregnant, mothers were asked about the occurrence and impact of recent life events causing them stress.

They completed a questionnaire that asked about 42 stressful events, including the death of a loved one, losing your job, financial and relationship issues, fears of miscarriage, and accidents. The mothers were asked to rate how severely they were affected by the occurrence of these events.

In turn, their children completed questionnaires about depressive symptoms on six different occasions between the ages of 10 to 19.

Using data collected from 10,569 mothers and children, Dr Colman from the University of Ottawa and his colleagues found that the children of mothers exposed to the highest levels of stressful life events in early pregnancy were 72% more likely to have chronic symptoms of depression throughout adolescence, even after the mother’s mental health and socioeconomic position were taken into account.

Dr Colman said:

We were interested in exploring the fetal-programming hypothesis, which is the idea that what happens to you in the womb can have long-term effects on your health.

This research underscores the importance of supporting expectant mothers. The reassuring news is that there is growing evidence that the effects of early life stress may be reduced or reversed if the child grows up in a supportive environment.