Maternal stress may increase ADHD risk in children later in life

New Delhi: As per a new study, stressful situations during pregnancy can increase stress hormone which can raise the risk of babies' developing attention deficit hyperactivity disorder (ADHD) later in life.

When human body is stressed, it releases cortisol -- stress hormones -- to handle higher stress, a mechanism that also persists during pregnancy. 

Stressful events during pregnancy causes the placenta -- which supplies the foetus with nutrients -- to emit cortisol.

As a result, a small amount of this hormone also enters the amniotic fluid -- a yellowish liquid that surrounds the foetus -- and affects foetal metabolism.

"If the mother is stressed for a longer period of time, the cortisol level in the amniotic fluid increases," said Pearl La Marca-Ghaemmaghami, psychologist at the University of Zurich in Switzerland. 

This higher concentration of stress hormone in turn accelerates the growth of the foetus. 

"An excessive acceleration of growth may occur at the expense of the proper maturation of the organs," added Ulrike Ehlert, psychologist at the University of Zurich. 

If an expectant mother is severely stressed over a longer period of time, the risk of the unborn child developing a mental or physical illness later in life -- such as ADHD or cardiovascular disease -- increases, the researchers noted, in the paper detailed in the journal Stress. 

However, short-term stress situations, did not seem to have an unfavourable effect on the development of the foetus.

(With Agency inputs)