Ultrasound tests do not seem to affect early development

The question: The high-frequency sound waves of an ultrasound examination help track the health and development of a fetus. Multiple scans, however, may lead to smaller babies at birth. Does this effect continue into early childhood?

This study followed 2,714 children born to mothers who, when pregnant with them, had been randomly given either five ultrasounds between 18 and 38 weeks of pregnancy or one test at 18 weeks. Those given multiple scans gave birth to smaller babies. During the first year, however, infants in the multiple-ultrasound group caught up in size. And, from ages 1 to 8, periodic examinations and standardized tests showed the two groups to be similar in size and in speech, language, behavior and neurological development.

Who may be affected by these findings? Pregnant women who undergo repeated ultrasound examinations, typically first given between 18 and 20 weeks into a pregnancy.

Caveats: Ultrasound can vary in intensity; whether the findings would apply if higher-intensity technology were used remains unclear.

Bottom line: Women who need more than one ultrasound to assess the health of a fetus may not need to worry about long-term effects on their child’s development.

Find this study: Dec. 4 issue of The Lancet; abstract available online at www.thelancet.com.

Learn more about ultrasound at www.mayoclinic.com and www.radiologyinfo.org.