- guardian.co.uk, Friday 8 September 2000 02.18 BST
Psychosocial stress affects the nervous system, hormone production, and the cardiovascular, metabolic and immune systems, say researchers.
"If stress is severe or prolonged, it could in theory induce congenital malformations through cortisone, one of the major stress hormones," write Dorthe Hansen and colleagues from the John F Kennedy Institute in Glostrup, Denmark.
Cortisone given to pregnant mice, they say, increases the risk of the young being born with a cleft palate, shortening of the head, shortening of the mandible and spina bifida. Some human studies have suggested that women with unwanted pregnancies are more likely to have a congenitally malformed baby, and stressful life events in pregnancy such as job loss, separation or bereavement have been associated with defects such as cleft lip and palate in babies.
To try to establish the real risk of severe stress in pregnancy, the Danish researchers identified women who suffered the death or life threatening illness of an older child or their partner while they were pregnant or up to 16 months previously, between 1980 and 1992.
They identified 3,560 such pregnancies, and randomly selected 20,299 others for comparison. Then they looked for malformations of what is known as the cranial-neural-crest (cleft lip and palate and heart malformations) which are thought to be vulnerable to environmental factors.
They found that women who suffered severe stress while pregnant were more likely to have a baby with congenital malformation such as a cleft palate, especially if the stressful event was the death of a child and if it occurred within the first three months of the pregnancy.
No significant effect was seen after the death or serious illness, cancer or heart attack, of a partner. "Severe life events in children may on average cause more stress in the woman than severe life events in partners," they write.
