This article is from the Pregnancy Screening FAQ, by Lynn Gazis-Sax (firstname.lastname@example.org) with numerous contributions by others.
This question turns out to be controversial. Some of the books which I
consulted reassured that ultrasound has been used for decades with little
risk, and that, while more studies could be done, the studies which have
been done confirm its safety. "Although the effects of ultrasound are
still being studied, no harmful effects to either the mother or the baby
have been found in over 20 years of use. The long-term risks of
ultrasound, if any, are unknown, but there are many benefits." (ACOG)
Others warn that it is insufficiently tested, and make comparisons with
X-rays and DES, which were once considered safe. The main area of debate
is whether ultrasound is being used too frequently in a routine fashion in
healthy pregnancies, without thorough enough testing. There may be some
association between ultrasound and low birth weight (Blatt). (Altho' this
is difficult to prove because the opposite assertion is known to be true:
i.e. if there is IUGR (intra-uterine growth retardation) US will be
performed more regularly to assess the progress of the baby.)
Some people express concern about the heat and cavitation (bubbling in
the cells). Others wonder whether routine ultrasound is cost effective,
or whether the money involved would be more effectively spent elsewhere.
A Consensus Development Conference of the National Institutes of Health
(NIH) was convened to consider the use of ultrasound in pregnancy, and
concluded that "Diagnostic ultrasound is considered to be a low-risk
procedure. However, routine use of ultrasound in pregnancy should be
discouraged." (Blatt) They recommended ultrasound only for twenty-eight
specific instances. (The use of diagnostic ultrasound in pregnancy.
Washington, DC. Government Printing Office, 1984.) In contrast, Germany,
France, and the UK have adopted a policy of ultrasound for all
pregnancies. (NEJM, 1/14/93, Prenatal Diagnosis)
From Robbrenner@aol.com (Robert Brenner MD):
The theoretical risk of fetal exposure to sound waves has never been shown
to cause any fetal damage. The biggest risk of ultrasound is
overinterpretation or missed diagnosis.
From: email@example.com (Suzanne Amador)