Repeated ultrasound examinations of a fetus during gestation does not
appear to affect an individual’s growth and development during childhood,
according to research by Australian scientists (Newnham et al. Lancet. 2004;364:2038-2044).
A randomized controlled trial published in 1993 by some of the same
researchers had found a significant increase in the proportion of growth-restricted
newborns exposed prenatally to ultrasound (5 times during pregnancy between
18 to 38 weeks’ gestational age) compared with newborns that had a single
prenatal scan at 18 weeks. To look for longer-term differences between the
two groups, the researchers performed a follow-up study in which they compared
the physical and developmental growth of about 2700 children at ages 1, 2,
3, 5, and 8 years. They found that the physical size of the infants from the
two groups were similar from age 1 year onward and that there were no significant
differences in speech, language, behavior, and neurological development between
the two groups.
Stephenson J. Fetal Ultrasound Safety. JAMA. 2005;293(3):286. doi:10.1001/jama.293.3.286-c