Mothers-to-be suffering stress in late pregnancy give birth to clumsier, more uncoordinated children, warned a study.
Their offspring's development can be affected by major events like divorce, moving home, losing a job or a relative's death.
Other major experiences which affect the last third of pregnancy can include financial hardship or marital problems.
Women who had to deal with three or more stressful events gave birth to the least coordinated children, said researchers.
They interviewed mothers-to-be when they were 18 weeks' pregnant and then at 34 weeks. The 2,900 children in the study were tested at the ages of ten, 14 and 17 using a ten-item movement test.
This tested abilities including hand strength, standing on one foot, turning a nut on a bolt, threading beads onto a rod and walking along a straight line.
Children born to mothers who suffered more stressful events in pregnancy recorded the worst scores on all three survey years.
Academics at the University of Notre Dame Australia suggested this is down to the accumulative effect of stress on the part of the child's brain called the cerebellar cortex which develops later in pregnancy.
Any resulting low motor development could be linked to ill-health and trouble with tasks like writing, throwing and running.
Money problems were the most common stress factor affecting just over a quarter of the pregnant women at 34 weeks, said the study in the journal Child Development.
The second was having a difficult pregnancy while the other most common reasons were moving home, marital concerns and problems with other children.
Study co-author Beth Hands, professor of human movement at the university, said it showed 'the importance of mothers' emotional and mental health on a wide range of developmental and health outcomes'.
Earlier work using animal models revealed reduced motor skills and balance in infant monkeys after repeated maternal stress. This research suggested the stress hormone cortisol may be causing the problems.
- Daily Mail