A series of papers on how scientists are learning to interpret clues that something is going wrong in the development of a foetus was presented to the British Psychological Society's annual conference in Belfast on Thursday.

The papers showed that:

• Breathing movements can be used to predict foetuses at risk of developing hernias in the diaphragm, the sheet of muscle that expands and contracts to allow the lungs to inhale and exhale air
• Leg movements can be used to monitor the deterioration of nerve function in foetuses with spina bifida
• It is possible at an early stage to identify foetuses that show problems in the development of the central nervous system as a result of diabetes in the mother
• Immature development in 25-week-old foetuses whose mothers smoke or drink can be indicated by a failure to be startled by noise

Alcohol risk

BBC correspondent Alison Hill: "Foetal behaviour gives clues about brain development"

The study into the impact of alcohol found that a pregnant woman who drinks just four glasses of wine a week risks damaging the brain of her baby.

Mothers-to-be who smoked as well as consumed alcohol did even more harm.

The startle response was tested by sounding a loud buzzer against the mother's abdomen.

A healthy foetus should respond immediately, extending its limbs, straining its back and turning its head before returning to a curled up resting position.

This is what was seen in 70% of women who abstained from cigarettes and alcohol. But among smokers and drinkers only 32% of foetuses acted normally.

The rest either did not react at all or responded in a half-hearted fashion.

Jennifer Little, who conducted the research on 129 mothers, said: "The results suggest some degree of neurological dysfunction."

But Sue Baker of the charity Alcohol Concern said it was "alarmist" to suggest one drink a day could harm an unborn baby.

Other studies showed that only drinking a large amount consistently could damage the foetus.

Standard test

Ultrasound can be used to monitor foetal activity

Professor Peter Hepper, of Queen's University, Belfast, worked on all four papers.

He told the conference that it should be possible to create a standard neurological test of the foetus to highlight impaired development of the brain and nervous system.

Professor Peter Hepper: "We are improving the ability to diagnose abnormality"

He said that foetal behaviour at 18-20 weeks could be monitored in all pregnant women to allow early identification of neurological problems.

Professor Hepper said: "As the behaviour of the foetus directly reflects its neurological functioning, observation of behaviour can provide information on neural well-being.

"It may well be possible that if we can plot the damage to the nervous system, we can make a decision on either to deliver the baby early before the nervous system is permanently damaged, or to perform some sort of corrective surgery in the womb before any damage has permanently occurred."

"What we are doing is improving our ability to diagnose abnormality before birth, and with that comes the opportunity to improve our treatment."

In a separate study, Professor Hepper and his team monitored the activity of 60 foetuses in the womb.

They found that most 20-week-old foetuses went through roughly equal periods of quietness and activity.

Those foetuses who were either almost continually active, or continually quiet were more likely to have developmental problems.

They found that increased activity was significantly associated with neural tube defects, such as spina bifida, and the presence of genetic abnormalities.

Decreased movement was significantly associated with ruptured membranes.