Having several ultrasounds during pregnancy does not harm the unborn baby or restrict the child’s growth or development early in life, Australian scientists said on Friday.

An ultrasound scan is a non-invasive procedure done routinely during pregnancy to assess the size, growth, health and gestational age of the foetus.

Earlier research had suggested that having several ultrasounds could increase right-handedness and affect the growth of the foetus, but Professor John Newnham, of King Edward Memorial Hospital in Subiaco, Australia, said the children grow and develop normally.

“Exposure to multiple prenatal ultrasound examinations from 18 weeks’ gestation onwards might be associated with a small effect on foetal growth but is followed in childhood by growth and measures of developmental outcome similar to children who had received a single prenatal scan,” he said in a report in The Lancet medical journal.

Newnham and his team studied the progress of about 2,700 children. Half had been exposed to repeated ultrasounds before birth. None had any congenital abnormalities.

The researchers assessed the growth and development of the children up to eight years old. At one year, both groups of children were similar in size. By the end of the study, there was no difference between the two groups in their results of standard speech, language, behaviour or neurological tests.

“Our results also provide reassurance that multiple prenatal ultrasound scans are not followed by smaller body size in infancy or childhood,” Newnham added.

Despite their reassuring results, Newnham and his colleagues said more research is needed.

“In view of the widespread and liberal use of this technology, we are responsible for ensuring the safety of its use,” he added.

SOURCE: The Lancet, December 4, 2004.