Stress leaves 'lasting legacy' in pregnancy

Published on Saturday 29 March 2008 19:29

EMMA Woods was a childminder and already had two children of her own, but her third pregnancy became one of the most stressful experiences of her life. Worse still, the 35-year-old from Orkney wonders if it has left a lasting legacy.

Woods fears the stress she suffered during those nine months could have had a direct effect on the health of her third child, Jack.

That is precisely the possibility highlighted by the research of Edinburgh University academic, Dr Mandy Drake. She believes stress hormones can cross the placenta and damage the development of the unborn child.

Even more disturbing, she believes it is possible for generations to be doomed to poor health by the process.

In Woods' case she was employed as a full time childminder and felt she could not cut her hours during pregnancy because it would cause her clients too many problems.

Instead, she carried on working despite feeling overwhelmed with responsibility and looking after her two other children, Hugh and Sophie.

She said: "I felt invaluable as a childminder because I was helping other working mums and I was worried about money. I worked until two weeks before my due date.

"I was really stressed with all the work I was doing and on top of it all my husband became ill. He collapsed at work one day and had to have a lot of tests done. Thankfully he was OK, but it caused a lot of anxiety."

When Jack, now five, was born, he suffered a variety of health problems. Woods couldn't help but feel guilty.

She said: "He did not sleep well and was very fractious and cried a lot. He had feeding problems and allergies. It has also turned out that he is severely deaf. I did have a lot of guilt and I did wonder whether it was because I was so stressed. But he is a very happy and sunny boy now."

Woods, who now works for the parenting internet site netmums.com, changed her career in order to reduce her stress.

She said: "In the end I gave up my job because it was all too much. I realised that my own son needed me more than the other children I was looking after."

A degree of stress is generally considered normal – even desirable – in most conditions. But the stress suffered by today's expectant mothers, many of whom want to carry on their careers, can be extreme.

Everyone has a certain amount of the "stress hormone" cortisol naturally present in the body but levels rise under stress.

Cortisol is secreted by the adrenal glands and helps the body in stressful situations by providing a burst of energy needed for 'fight or flight'.

The base level of cortisol fluctuates throughout the day. In the morning it is higher and it reduces by evening.

The average level of cortisol is measured in nanomoles per litre and in a healthy adult would be between 150 and 500nmol/l. But under stress – such as a person on the night before an operation – this level could double to 300 and 1,000nmol/l. Sustained exposure to these levels is likely to cause serious health problems, including high blood pressure.

Usually the placenta stops most of the mother's stress hormones reaching the baby. But it is thought that if there are high levels of the hormones, or if the placenta is not working properly, significant amounts reach the unborn child.

One theory is that while the developing baby is exposed to the stress hormone their own developing reproductive organs may also be damaged, which would affect the health of future generations.

Drake will explain her research at a presentation at the Edinburgh International Science Festival on Wednesday.

Much of the work has been done on rats and mice administered with synthetic hormones. The scientists found that the more stress hormone they received, the greater the effects. Now Drake will carry out studies on babies, testing their cord blood and saliva, to try to identify those at risk.

The findings were last night met with concern from parents' groups. Cathy Rogan, a rights adviser for the campaigning charity Working Families, said: "There are plenty of reasons why pregnant woman suffer stress, including money worries and employment issues. Many just don't know what they are going to be living on when the baby comes and worry about the cost of childcare.

"I am concerned at these findings because there is a lot that can be done by employers to reduce working women's stress, such as reducing long hours and recognising that pregnant women do suffer fatigue and ill health.

"But there is often antagonism between women and their employers about who's getting the most out of the situation. Many women find their employer is not sympathetic. However, I hope this research does not make women even more stressed."

A survey last year by the baby charity Tommy's showed that 90% of 1,100 women suffered stress in pregnancy with money troubles the chief concern. Many worried about developing post-natal depression, and that they might not love their baby.

Andrew Shennan, professor of obstetrics for Tommy's said: "It is vital that we reassure pregnant women that it is OK to feel confused and uncertain during pregnancy."

Dr Lisa Thorn, a researcher from the Psychophysiology and Stress Research Group at the University of Westminster, London, said: "What goes on in your head does impact your health and it impacts on different people in different ways. To what extent depends on the person, the level of stress and how they appraise something as being stressful or not."