I had posted a question about this under the mammography thread. WOW - I am amazed, but maybe not so amazed : ( that it is true. Well, my first baby I lost due to a major defect - amniotic banding, that was discovered by an OB/GYN/Geneticist (friend's husband) doing one of those just-for-fun ultrasounds. So baby #2 I got a couple ultrasounds to make sure. He's 11 now and perfectly OK, above average intelligence, right-handed, etc. LOL. Baby #3 a decade younger, me a decade older, refused amniocentesis, but agreed to high-level ultrasound, had to go back for a second because the dates/AFP were messed up...baby is also seeming to be of above-average intelligence, ahead developmentally, even-tempered, and is um, left-handed. Course, I work in statistics, also am ambidextrous so go figure.
But...seeing someone started a thread about this, I did a little searching and enclose the following...seems safety of ultrasound and doppler is not really a given. I'm thinking my next baby I will refuse all testing, what's the point if it's not safe...not like I would terminate my pregnancy (though with baby #1 it was good to know not to try to stop a natural miscarriage at 5 months along, and to know what to expect). I only had the one ultrasound so I know that's not what caused the defects, BTW.
Quote to follow, I'm sure there are other articles...but this is from a reputable journal. When they refer to thermal...what they mean is that if the operator stops moving the imaging probe for about 30 seconds, it can heat the bone up and cause damage to the surrounding tissue. Oh that is gross - like microwaving your fetus practically. Oh my! Ultrasounds are not something for just anybody to play around with. I feel better that my doctor sent me to a high-risk pregnancy center where they at least had technicians who were properly trained...but I have heard in other countries, these machines are used by who-knows-who to determine sex of baby. Maybe a lot of misuse by untrained people. Poor babies.
1: J Matern Fetal Med 2001 Apr;10(2):75-84
Guidelines and recommendations for safe use of Doppler ultrasound in perinatal
Barnett SB, Maulik D; International Perinatal Doppler Society.
Commonwealth Scientific and Industrial Research Organisation, Lindfield, NSW,
Technological development has led to significant improvements in
ultrasonographic capabilities in recent years, and this has been accompanied by
increases in acoustic output. Meanwhile, there is a developing trend to use
ultrasound at early stages of pregnancy when the developing embryo is known to
be highly sensitive to damage by physical agents. The advent of pulsed spectral
Doppler and color flow imaging has revolutionized perinatal applications.
Doppler ultrasound has become widely accepted as a valuable diagnostic tool in
obstetric medicine, where it has particular benefits for high-risk pregnancies.
The benefits of Doppler screening are less well established. United States Food
and Drug Administration (FDA) regulations now provide an option whereby
equipment that provides a form of output display can be used to apply
substantially higher acoustic output to the embryo or fetus than equipment
approved for use under application-specific intensity limits. The Output Display
Standard recently adopted by the FDA, in the USA, encourages self-regulation of
acoustic exposure by the ultrasound user, on the basis of assumed knowledge of
the implications of biophysical interactions. When modern sophisticated
equipment is used at maximum operating settings for Doppler examinations, the
acoustic outputs are sufficient to produce obvious biological effects, e.g.
significant temperature increase in tissue or visible motion of particles due to
radiation pressure streaming effects. The risk of inducing thermal effects is
greater in the second and third trimesters, when fetal bone is intercepted by
the ultrasound beam and significant temperature increase can occur in the fetal
brain. Non-thermal bioeffects may be more significant in early gestation, when
the relatively loosely tethered embryonic tissues are exposed to an ultrasound
beam in a liquid path. The likelihood of producing cavitation-type non-thermal
effects is enhanced by the presence in the sound-field of gas-encapsulated
echo-contrast media. To ensure the continued safe use of ultrasound in
obstetrics, it is important that international ultrasound organizations, such as
the International Perinatal Doppler Society, issue advice to members to allow
sensible assessment of risk: benefit and the practical implementation of the
ALARA (as low as reasonably achievable) principle.
PMID: 11392597 [PubMed - indexed for MEDLINE]