CONTACT: JENNIFER BROWN
Iowa City IA 52242
(319) 335-9917; fax(319) 384-4638
Release: April 30, 2002
NOTE TO EDITORS: the following is adapted from a news release prepared by
the American Roentgen Ray Society
New UI policy for imaging pregnant, possibly pregnant patients presented
In an effort to ensure the well-being of pregnant and possibly pregnant
patients, University of Iowa researchers have developed a policy to guide
the use of radiation to diagnose these patients.
The new policy, which has been in place at the UI Hospitals and Clinics
for about six months, will be presented by Meghan Blake, UI medical student,
today at the annual meeting of the American Roentgen Ray Society in Atlanta,
Ga. Blake was part of the UI team that devised the policy. The team also included
Georges El-Khoury, M.D., UI professor of radiology and orthopaedic surgery,
and Mark Madsen, Ph.D., UI associate professor of radiology.
In recent years, newer imaging technologies such as multi-slice spiral computed
tomography (CT) scanners have become increasingly common in hospitals. These
technologies are extremely useful diagnostic tools. For example, in the emergency
room a CT scan can rapidly assess a trauma patient's injuries. However, CT
imaging uses relatively high doses of ionizing radiation, and exposure to
these levels of ionizing radiation may pose a small but real risk for a fetus.
Previous scientific studies show that health risks associated with radiation
to the fetus are small for the dose levels delivered by most diagnostic procedures,
and no proven effects have been observed for total radiation doses to the
fetus less than 5 rem (unit of radiation). However, the UI team reasoned that
it made sense to be sure that pregnant patients and the physicians treating
them were aware of the potential risks and were in a position to take steps
to limit a fetus's exposure to radiation.
"Surprisingly, a search through the medical literature and an informal
survey of some academic radiologists yielded a lack of clear policies or specific
instructions on this issue," Blake said. "CT and other methods that
use radiation are an integral part of how we diagnose acute care patients;
it became apparent that a policy was needed."
The UI team devised a policy to establish guidelines for use when a pregnant
or potentially pregnant patient requires a CT scan or other form of diagnostic
radiology. The overall goal of the policy is to protect the mother because
her well being preserves the life of the fetus. However, in achieving this
goal, the guidelines lay out measures aimed at keeping the radiation dose
to the fetus to a minimum.
The policy eliminates ambiguity, allows for consistency, and helps ease
patients' fears, Blake said.
The guidelines apply to all departments in the hospital and mean that all
women ages 12 to 55 who require radiography are asked if they are or could
be pregnant. If the woman can't communicate, a pregnancy test is done, if
The policy states that if the woman is pregnant or could be pregnant, then
the following applies:
-- If her injuries are not in the pelvic area or area nearby, the fetus
would not be in the direct x-ray beam, so the patient is told that there is
no scientific evidence of harm to the fetus. Pelvic shielding is used, and
the radiation doses are kept as low as possible.
-- If the estimated dose to the fetus is less than 1 rem (from examinations
such as a lumbar spine radiograph and an x-ray of the kidney and bladder),
the radiologist should consider alternative imaging methods, such as ultrasound.
If there is no alternative, the patient must be told there is a minimal risk
to the fetus, and all efforts should be made to keep the radiation dose as
low as possible.
-- If the estimated dose for the fetus is 1-5 rem (such as with fluoroscopy,
abdominal CT, pelvic CT or angiography) an alternative imaging method should
be considered. If there is no alternative, the patient must sign an informed
consent form indicating she understands that there is a "minimally increased
risk" of congenital abnormalities and childhood cancers. Women who are
two to 15 weeks pregnant are particularly at risk, noted Blake.
-- If the estimated dose is greater than 5 rem (such as with repeated CT
and longer fluoroscopy) the physicist should formally calculate the dose,
the patient's chart should document the opinions of the radiologist, the physician
who referred the patient for the test and the physicist. The patient must
sign an informed consent form that notes her understanding of "increased
risk" to the fetus.
In addition, the policy recommends that repeat examinations be eliminated
and contrast media (chemicals used to enhance CT imaging) be used with caution.
University of Iowa Health Care describes the partnership between the
UI Roy J. and Lucille A. Carver College of Medicine and UI Hospitals and Clinics
and the patient care, medical education and research programs and services
they provide. Visit UI Health Care online at www.uihealthcare.com.