Researchers have been testing 24-week-old foetuses’ capacity to learn by a technique known as habituation which involves feeding sounds or music into the womb through an earphone held against the mother’s abdomen, writes David Budge.

At first the foetus responds by a movement or change in heartbeat, but after several repetitions the response stops. Professor Peter Hepper, director of the foetal behaviour centre at Queen’s University, Belfast, believes that this is because the foetus has “learned” the sound and is ready to assimilate more information. Tests of this kind have already been given to four-month-old babies to provide accurate predictions of school performance at age 10 or 11, he told the conference.

The Belfast research has also shown that the intellectual superiority of girls is evident in the womb. At 24 weeks, girls are already a fortnight ahead of boys in their capacity to assimilate information, Professor Hepper said. It has also been proved that a foetus can distinguish its own mother’s voice and show a preference for it at about 30 weeks. The foetus begins to develop its sense of taste and smell within nine weeks of conception by drinking the amniotic fluid and eventually learns to identify its mother’s smell.

Psychologists have been using the tests primarily to distinguish normally developed foetuses from Down’s syndrome babies with varying degrees of handicap. Down’s syndrome can be detected at an ante-natal screening but until now there has been no method of establishing how handicapped the baby will be.

Although the mental ability of a foetus cannot currently be gauged before 24 weeks, Professor Hepper said that improvements in testing techniques may eventually enable women to make informed decisions on whether to terminate a Down’s pregnancy. He is now monitoring the development of seven Down’s babies aged between 3 and 18 months to check the accuracy of the predictions based on the womb tests.