German doctors save world's smallest boy

Premature babies are less intelligent than infants born at full-term, a study suggests.

Researchers in the United States have found that infants born early are slower at processing information and understanding what they see.

They believe that this gap continues throughout life and dooes not narrow with age.

There was no evidence that the gap in performance narrowed with age or that the pre-terms caught up

Dr Susan Rose
The study backs up previous findings suggesting that on average babies born before nine months are less intelligent.
Dr Susan Rose and colleagues at Albert Einstein College of Medicine in New York studied 153 full-term and 59 pre-term infants at five months, seven months and 12 months. The pre-term infants had all been born weighing less than four pounds.

Picture tests
The infants were presented with a series of pictures of paired faces, one that remained the same across the trials and one that changed.

The trials continued until an infant showed a consistent preference for the new faces.

The researchers found that as early as five months of age, pre-terms were significantly slower at processing the paired faces than full-terms.

Pre-terms took about 20% more trials and 30% more time than full-terms to study the paired faces and reliably recognise the new faces.

The differences were similar at all three ages and there was no evidence that the gap narrowed with age or that the pre-terms caught up.

Writing in the journal Developmental Psychology, the researchers said: "The results of this study indicate that pre-terms are markedly slower at processing information than full-terms."

They added: "The pre-term/full-term differences were similar at all three ages. Thus, there was no evidence that the gap in performance narrowed with age or that the pre-terms caught up."

Birth complications
Previous studies have suggested that slower processing speeds among pre-terms could be linked to adverse incidents at birth, such as a lack of oxygen.

The researchers assessed those pre-terms who had been on respirators after their birth.

They found a link between the amount of time they spent on respirators and slower response times.

This was particularly noticeable at five and seven months. However, it was no longer significant at 12 months.

They authors concluded that just being born prematurely may be to blame.

"It is possible that premature birth itself, independent of any associated medical conditions, may play a part," the said.

The researchers suggested exposing underdeveloped sensory systems before they are fully developed may be factor.

A study by UK doctors, published last year, found that one in three children who had been born premature had learning problems later in life.

Dr Charlotte Huddy found that many had difficulty in school with writing, mathematics and reading. Some also had behavioural problems.