It appears that concerns about the effects of repeated ultrasound exposure on early childhood development are unfounded. In an Australian study released this week, researchers report that babies who were exposed to five ultrasounds during pregnancy were no more at risk to have slow growth development than babies who were only exposed once.

The study, which was conducted over a fifteen-year period at the King Edward Memorial Hospital in Perth, kept track of 2500 children who were born with no apparent congenital abnormalities. These children were examined at one, two, three, five, and eight years old. Half of the subjects had been exposed to repeated ultrasound, while the other had only had one such exposure prior to birth.

All the babies were similar in size at birth and maintained the same rate of growth from the year of one on. They showed no differences in speech, language, behavior, and neurological development.

John Newnham of the University of Western Australia at King Edward Memorial Hospital is quite positive about the results of this study, stating, “Exposure to multiple prenatal ultrasound examinations from 18 weeks' gestation onwards might be associated with a small effect on fetal growth but is followed in childhood by growth and measures of developmental outcome similar to those in children who had received a single prenatal scan.”

The study was published in the December 4 edition of The Lancet.