Mothers who are stressed out in pregnancy 'transmit' the effect to their unborn baby as early as 17 weeks, claim scientists.
They have matched the level of stress hormones found in the mother's blood to those in fluid surrounding the fetus.
It is the first time a link has been established between mother and child's stress levels at such an early stage in pregnancy.
Previous research suggests stress hormones activated by maternal anxiety may have a long-term effect on the child's brain development and future behaviour.
Researchers led by Professor Vivette Glover at Imperial College London and Dr Pampa Sarkar of Wexham Park Hospital, Berkshire, studied 267 women, taking a blood sample from the mother and a sample from the amniotic fluid surrounding the baby.
They measured levels of a stress hormone called cortisol in both samples, says a report published today (thurs) in the journal Clinical Endocrinology (must credit).
At the age of 17 weeks and older, they found the higher the level of cortisol in the mother's blood, the greater the level of cortisol in the amniotic fluid.
Source - Daily Mail