Study finds worrisome increase in medical imaging during pregnancy

Use of medical imaging during pregnancy increased significantly in the United States, a new study has found, with nearly a four-fold rise over the last two decades in the number of women undergoing computed tomography CT scans, which expose mothers and fetuses to radiation. Pregnant women are warned to minimize radiation exposure.

This is the first large, multi-center study to assess the amount of advanced imaging occurring during pregnancy. The study, which included authors from UC San Francisco, UC Davis and Kaiser Permanente, published July 24, 2019, in JAMA Network Open.

Over the 21-year study period, rates of CT increased nearly four-fold in the United States and doubled in Ontario, Canada.

Most pregnant women get routine ultrasound to monitor fetal growth, which delivers no ionizing radiation. But occasionally, doctors may want to use advanced imaging to detect or rule out a serious medical condition of the expectant mother, most often pulmonary embolism, brain trauma or aneurysm, or appendicitis."

Co-lead author Diana L. Miglioretti, PhD, biostatistics professor at the UC Davis Department of Public Health Sciences and senior investigator with Kaiser Permanente Washington Health Research

Always, but especially if you're pregnant, you should ask whether it is really medically necessary to have any imaging test that involves ionizing radiation.

That imaging could include CT, which involves a large dose of ionizing radiation – many times more than a chest X-ray. Ionizing radiation carries potential health risks to the developing fetus, including congenital abnormalities, developmental delays, or cancer.

"Imaging can be helpful, but it can be overused," said senior author Rebecca Smith-Bindman, MD, a UCSF professor of radiology, epidemiology and biostatistics, and of obstetrics, gynecology and reproductive medicine. "Always, but especially if you're pregnant, you should ask whether it is really medically necessary to have any imaging test that involves ionizing radiation."