30-week-old babies in the womb already have short-term memory capabilities, a new study from the Netherlands, published in the July/August 2009 issue of the journal Child Development, has found.

Researchers at Maastricht University Medical Centre and the University Medical Centre St. Radboud examined 93 healthy pregnant Dutch women and their unborn children, measuring changes in how the child responds to repeated stimulation. The children were tested at 30, 32, 34, and 36 weeks, and again at 38 weeks gestation.

The study showed that the unborn children would initially respond to a “vibroacoustic” stimulus. The stimulus would then be repeated every 30 seconds until “habituation” occured, and the children no longer reacted, evidently accepting the sound as safe. Ultrasonography showed that in a second session ten minutes after the first, the children apparently “remembered” the stimulus and the number of stimuli needed for habituation grew much smaller.

The scientists found that at thirty weeks, the child in the womb has a short-term memory of about ten minutes. At 34 weeks, the child can store information and retrieve it up to four weeks later. The younger children who had been tested at 34 and 36 weeks were later able to habituate much faster than children at 38 weeks who had never been tested.

“This is the next step into a better insight in the development of the foetal central nervous system,” said study co-author Dr. Jan G. Nijhuis, director of the Centre for Genetics, Reproduction and Child Health at Maastricht University Medical Centre in the Netherlands. “We aim to develop an ‘intra-uterine neurologic examination,’ which could then be used in foetuses at risk.”

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