
Keeping Ultrasound in its Place
By Wendy Priesnitz
For many parents-to-be, one of the
frustrating aspects of pregnancy is the lack of a window into their
unborn child’s world. There is a technological fix for that, in the form
of ultrasound or sonograms. First used in obstetrics in the middle of
the twentieth century, they are now a routine part of prenatal treatment
and pregnancy scans can be performed to detect developmental defects
before birth.
In recent years, some clinics are offering
ultrasound scans without a doctor’s order in order to determine babies’
gender and to create keepsake photos and even 3-D movies of fetal
development. This non-medical practice is being discouraged by
governments and medical associations.
The U.S. FDA says that ultrasound
heats tissues slightly, and ultrasounds can also produce very small
bubbles in some tissues, which is called cavitation. “The long-term
effects of tissue heating and cavitation are not known. Therefore,
ultrasound scans should be done only when there is a medical need,” the
agency advises. It also says that ultrasounds administered by untrained
technicians might reveal a complication or anomaly that is
misinterpreted.
Research interest in this topic is increasing. A study was
published online in September of 2016 in the journal Autism
Research. The authors, led by Pierre D. Mourad, PhD, University of
Washington, Seattle, report that early prenatal diagnostic ultrasound
has been linked to variability in symptoms of autism spectrum disorder
(ASD) in children with specific genetic vulnerabilities. The authors
note that these results “add weight to ongoing concerns” expressed by
the US Food and Drug Administration (FDA) about the nonmedical use of
diagnostic ultrasound during pregnancy.
Several organizations have
also released statements regarding keepsake ultrasound.
The European Committee for Medical Ultrasound
has said: “The embryonic period is known to be particularly sensitive to
any external influences. Until further scientific information is
available, investigations should be carried out with careful control of
output levels and exposure times. With increasing mineralization of the
fetal bone as the fetus develops, the possibility of heating fetal bone
increases. The user should prudently limit exposure of critical
structures such as the fetal skull or spine during Doppler studies (a
type of ultrasound that detects movement, direction and speed, such as
fetal heartbeat).”
The American Pregnancy Association states:
“The ultrasound is a non-invasive procedure that, when used properly,
has not demonstrated fetal harm. However, the long term effects of
repeated and/or lengthy ultrasound exposures on the fetus are not fully
known.”
The Society of Obstetricians and
Gynaecologists of Canada (SOGC) and the Canadian Association of
Radiologists issued a warning against “entertainment” ultrasounds in a
joint policy statement, warning that every ultrasound involves exposes
the fetus to “targeted energy,” and carries a theoretical risk of some
harm.
So it is probably safer to keep that window
closed and use your imagination until birth.
Wendy Priesnitz is Natural
Child Magazine's editor. She has been a journalist for forty years and
is the author of thirteen books.
|