Should you get scanned when you are pregnant? (Susan Farley for The New York Times)
Pregnant women are exposed to twice the amount of radiation from medical scans as they were a decade ago, a new study has found.
Although the total amount of radiation exposure to pregnant women is still relatively low, the doubling effect in just a decade is the latest indicator that medical scans are exposing patients to record amounts of ionizing radiation, a type of radiation that can alter cells and lead to health risks, including cancer .
Researchers from Brown University’s Warren Alpert Medical School looked at the use of several imaging techniques that can expose a patient to ionizing radiation, including nuclear medicine exams, CT scans and plain-film X-rays. They studied more than 3,200 patients who had received scans from 1997 to 2006, some of whom were pregnant. The investigators found that during this time, the number of imaging studies that would expose pregnant women to radiation increased by 121 percent . The findings are being presented today at the annual meeting of the Radiological Society of North America.
The greatest increases were in the number of CT scans performed, although such scans aren’t routinely done during pregnancy. The most common scan performed during pregnancy, an abdominal ultrasound, does not expose the patient or fetus to ionizing radiation. The data showed that the use of scanning tests is increasing far more rapidly than the number of deliveries, which rose only 7 percent during the period.
Earlier this year, a government study found that the p er-capita dose of potentially hazardous ionizing radiation from clinical imaging exams in the United States increased almost 600 percent in the last 25 years. The use of CT scans in particular is on the rise, jumping to 62 million in 2006, from 3 million in 1980. CT scans expose patients to far more radiation than standard X-rays.
The notion that pregnant women are also being scanned at an increasing rate is even more troubling, given that exposure to excess radiation can severely damage a developing fetus. Some of the rise is due to the fact that better technology is now available to diagnose abnormalities, said Dr. Elizabeth Lazarus, assistant professor of diagnostic imaging at Brown. She added that hospitals and insurers also want to make fast diagnoses to shorten hospital stays and improve care, which may prompt doctors to order scans more often.
In some cases the benefits of a scan to both mother and baby far outweigh the risks, but the latest data suggest doctors are not always being circumspect before ordering scans of pregnant women. “I want to assure patients that CT can be a safe, effective test for pregnant patients,” said Dr. Lazarus. “However, there are alternatives that should at least be explored. Pregnant patients should ask their doctors about other imaging or diagnostic tests that may not expose the fetus to radiation.”