Ultrasound Might Affect Baby’s Brain Development
August 8, 2006
Preliminary findings in mice suggest that fetal ultrasound might affect newborn brain development.
In baby mice whose mothers were exposed to ultrasound for 30 minutes or longer during pregnancy, a small but significant number of nerve cells did not migrate to their proper locations in the brain, Yale University researchers reported in this week’s Proceedings of the National Academy of Sciences.
"These results call for a further investigation in larger and slower-developing brains of non-human primates and comprehensive epidemiological studies in humans," the team wrote.
But Dr. Pasko Rakic, chairman of the Yale department of neurobiology and leader of the study, was quick to offer parents reassurance about the safety of ultrasound — done for the proper reasons — in human pregnancies.
"If I had a daughter and she was pregnant, I would recommend she had it for medical reasons," Rakic said.
"I couldn’t agree with him more," said Dr. Joshua Copel, a professor of obstetrics, gynecology and reproductive sciences at Yale and spokesman for the American College of Obstetrics and Gynecology(ACOG).
"The forms of migration [of brain cells] and the timing of migration differ in primates like humans than in mice," Copel said.
A study reported in 2004 by Australian researchers found that repeat ultrasound exams during pregnancy had no long-term effect on either the mental function or growth of children.
They reported no significant differences among the children that might indicate prenatal ultrasound exams had deleterious effects on development.
Nevertheless, Copel said, there is good reason to follow ACOG guidelines, which state that "the lowest possible ultrasound setting should be used to get the necessary diagnostic information" and that the examination should be as brief as possible.
While ACOG recommends that ultrasound examinations be done for specific reasons, such as a suspected ectopic pregnancy, a possible miscarriage or detection of possible birth defects, many physicians include one examination as part of routine care, at 18 to 20 weeks of pregnancy.
- Summarized from: HealthDay News, via Forbes.com, Aug. 8, 2006
Ultrasound and Warfare?
The history of ultrasound may surprise you:
The basic technique of ultrasound does not have its roots in obstetrics or in medicine, but in warfare.
During the First World War, detection by sound waves of underwater objects developed as a useful way of identifying underwater submarines.
After the war, the technique of ultrasonic echo sounding was applied to mapping the ocean floor for the shipping and navigation industry and for locating deep-sea herring shoals.
The pioneer medical work on soft-tissue ultrasonography was carried out in the USA in the late 1940s and early 1950s, and the translation into obstetrics occurred in the mid-1950s, with much of the original work being done by Professor Ian Donald and his colleagues in Glasgow.
The original clinical task spurring Donald and his team to apply ultrasound to the female abdomen was not the surveillance of pregnancy but the diagnosis of abdominal tumours, particularly the diagnostic separation into benign and malignant tumours.
Glasgow was a city with heavy engineering commitments, where ultrasound was already used in the metal industry. Donald was familiar with this work, and it occurred to him to try on human tumours the industrial ultrasound equipment used for detecting flaws in metals.
The technique worked, and, from the summer of 1955, women patients presenting with obscure abdominal complaints were liable to find the doctor putting transformer oil on their tummies as an acoustic coupling medium for an industrial metal-flaw detector.
- Source: Essays on Women, Medicine and Health, by Ann Oakley. Edinburgh University Press, Edinburgh. 1993, page 190.
The best online guide to all you’d want to know about Ultrasound is Obstetric Ultrasound, created by Dr. Joseph S.K. Woo.
Why and when is Ultrasound used in Pregnancy?
Dr. Woo’s guide shows that Ultrasound is used in the following areas:
- Diagnosis and confirmation of early pregnancy
- Vaginal bleeding in early pregnancy
- Determination of gestational age and assessment of fetal size
- Diagnosis of fetal malformation
- Placental localization
- Multiple pregnancies
- Hydramnios and Oligohydramnios
- Other areas
The latter include:
a) confirmation of intrauterine death.
b) confirmation of fetal presentation in uncertain cases.
c) evaluating fetal movements, tone and breathing in the Biophysical Profile.
d) diagnosis of uterine and pelvic abnormalities during pregnancy e.g. fibromyomata and ovarian cyst.
Resources
- Step by Step Ultrasound in Obstetrics
- Obstetric Ultrasound
- How Ultrasound Works
- God’s Miracle of Life with Dr. William Lile [DVD]
- 3D Ultrasound pictures
- Ultrasound video
