Results of a study from Australia in this week's issue of THE LANCET provide reassurance to the safety of repeated ultrasound examination during pregnancy.
10 years ago a randomised trial highlighted how repeated ultrasound exposure at 5 different times during pregnancy was associated with growth restrictions among new-born babies compared with children exposed to only one ultrasound examination in utero.
The current analysis provides long-term follow-up data on the growth and development of children from the original study. Physical and developmental assessments were done at 1, 2, 3, 5, and 8 years of age on children born without congenital abnormalities and from singleton pregnancies. Follow-up data were available for around 2700 children, half of whom had been exposed to repeated ultrasound, the other half to one ultrasound exposure before birth.
Physical sizes of infants were similar in the two groups from one year of age onwards. There were no significant differences indicating deleterious effects of multiple ultrasound studies at any age as measured by standard tests of childhood speech, language, behaviour, and neurological development.
Lead investigator John Newnham (university of Western Australia at King Edward Memorial Hospital, Perth) comments: "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."
Contact: Professor John P Newnham, School of Women's and Infants' Health, King Edward Memorial Hospital, 374 Bagot Road, Subiaco 6008, Australia;
T) 61-8-9340-1331;
jnewnham@obsgyn.uwa.edu.au
Journal
The Lancet