No comment. Be safe.
Effects of Frequent Ultrasound During Pregnancy: A Randomized Controlled Trial.
By J.P. Newnham, S.F. Evans, C.A. Michael, F.J. Stanley, and L.I. Landau (1993). The Lancet, 342 (Oct.9), 887-891.
A study of over 1400 women in Perth, Western Australia compared pregnant mothers who had ultrasound only once during gestation with mothers who had five monthly ultrasounds from 18 weeks to 38 weeks. They found significantly higher intrauterine growth restriction in the intensive ultrasound group. These mothers gave birth to lower weight babies.
The researchers concluded that prenatal ultrasound imaging and Doppler flow exams should be restricted to clinically necessary situations. This recommendation comes at a time when ultrasound during prenatal visits has become increasingly popular and serves as a kind of entertainment feature of office check-up visits.
Case-Controlled Study of Prenatal Ultrasound Exposure in Children with Delayed Speech.
By J.D. Campbell, R.W. Elford and R.F. Brant (1993). Canadian Medical Association Journal, 149(10), 1435-1440.
Delayed speech is not a pathological or organic syndrome but a developmentally defined symptom complex. Clinicians have noted an increased incidence of delayed speech in pediatric patients.
This is a matched-case control study of 72 children 2 to 8 years old presenting with delayed speech of unknown cause. The children were measured for articulation, language comprehension, language production, meta-linguistic skills, and verbal memory. When checked for ultrasound exposure, the speech-delayed children were about twice as likely to have been exposed to ultrasound than the matched controls.
The authors believe that delayed speech is a sensitive measure reflecting sub-optimal conditions for development. If ultrasound can cause developmental delays, the authors are concerned about the routine use of ultrasound and they warn against it.