Stress during Pregnancy 'lowers a child's IQ'

From the Daily Mail, Thursday November 24th 2005

By Fiona MacRae- Science Reporter

Worrying during pregnancy could stunt a child's intelligence, women were warned last night.

Stressed mother-to-be double the risk of their toddlers having lower than average IQs, research shows.

The children are also more likely to be hyperactive, have emotional problems, not do as they are told and suffer from stress themselves.

It is thought high levels of a stress hormone in the womb may affect the brain of the developing child.

Researcher Professor Vivette Glover said the study showed stress during pregnancy to be a major public health issue.

The biggest sources of stress include pressure at work, unhappy marriages, mental health problems and anxiety about pregnancy.

Professor Glover, of Imperial College London, followed the progress of almost 7 women and their children. The study looked at how stressed the women were during pregnancy.

It then measured the mental development of the children at 18 months. The toddlers took a basic intelligence test involving tasks such as slotting shapes into holes, scoring 100 on average.

But those whose mothers were stressed during pregnancy scored much lower.

Professor Glover said: "We found that if the woman has been very stressed when pregnant, the child scored about 90. Stress has a very marked effect on the child's mental development."

She added that it was "highly likely" a similar effect would be found in older children.

But not all children whose mothers reported being stressed while pregnant had lower scores, suggesting genetic make-up plays a part.

In a separate study, Professor Glover- who last night addressed a conference held by employment lawyers Russell Jones and Walker- followed 7,000 women from pregnancy to their child's tenth birthday.

Tests when the children were four and seven showed stress during the later weeks of pregnancy was linked to long- tern behavioural problems.

Those whose mothers were stressed or anxious while carrying them were twice as likely to be hyperactive, have emotional problems and disobey orders.

Professor Glover said: "We found there was a twofold increase in the likelihood of children exhibiting behavioural problems at seven years if their mothers reported being stressed in the later stages of pregnancy. It seems anxiety in the earlier stages of pregnancy is not so important."

"But later on, it would seem anxiety in mothers has an effect when the foetuses' brains are more formed."

The latest tests, taken when the children were ten, looked at levels of the hormone cortisol, which increases during stress.

Those whose mothers had stressful pregnancies had higher levels of the hormone. This suggests the children were more stressed themselves.

High levels of cortisol are also linked to anxiety, depression and memory problems.

Professor Glover said: "It all points to reducing stress in pregnancy. If people are stressed, it matters. It is a big public health issue."