Multiple Pregnancy Ultrasounds Safe for Child

Having multiple ultrasound examinations during pregnancy (search) is unlikely to cause any lasting harm to the developing fetus, according to a new study that confirms the long-term safety of the commonly used procedure.

A study released 10 years ago by the same researchers showed that repeat pregnancy ultrasounds were associated with stunted growth among newborn babies compared with babies who were exposed to only one ultrasound during pregnancy.

But this follow-up study shows that there were no long-term differences in the growth and development of the children involved in the original study.

Although ultrasound examinations during pregnancy are widely accepted as safe for both mother and child, researchers say the scientific evidence to back up that notion is not comprehensive. But researchers say these results should provide reassurance that multiple prenatal ultrasounds have no negative effects on the growth or development of the fetus.

Multiple Ultrasounds Safe During Pregnancy

In the study, researchers compared the physical and developmental growth of about 2,700 children at ages 1, 2, 3, 5 and 8. All the children had been exposed to ultrasound during pregnancy. About half were exposed to five ultrasound examinations during pregnancy; the other half was exposed to one.

The results showed that the physical size of the infants was similar in the two groups from 1 year of age onward.

In addition, there were no significant differences in speech, language, behavior, and neurological development between the two groups.

Researcher John Newnham, MD, of the University of Western Australia at King Edward Memorial Hospital in Perth, says exposure to multiple ultrasound examinations during the first 18 weeks of pregnancy onward might be associated with a small effect on fetal growth, but there are no differences in growth and development in childhood compared with children who received a single ultrasound exam.

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Newnham, J. The Lancet, Dec. 4, 2004; vol 364: pp 2038-2044. News release, The Lancet.