TUESDAY, Aug. 20, 2019 (HealthDay News) -- A small but "concerning" number of pregnant women are exposed to a commonly used magnetic resonance imaging (MRI) contrast agent, often early in the pregnancy and likely before they are aware of the pregnancy, according to a study published Aug. 20 in Radiology.
Steven T. Bird, Ph.D., Pharm.D., from the U.S. Food and Drug Administration in Silver Springs, Maryland, and colleagues used data from the Sentinel Distributed Database to identify U.S. pregnancies that resulted in live births (2006 and 2017) from 16 data contributors. The prevalence of MRI procedures with and without a gadolinium-based contrast agent (GBCA) among pregnant and matched nonpregnant women was evaluated for anatomic location and trimester.
The researchers found that of the nearly 4.7 million pregnancies, there were 6,879 exposures to GBCAs in 5,457 pregnancies (0.12 percent of all pregnancies), or one contrast-enhanced MRI examination per 860 pregnancies. Roughly half of contrast-enhanced MRI examinations were performed in the head (3,499 procedures), although pelvic and abdominal MRI comprised 22.3 percent of all contrast-enhanced MRI examinations during pregnancy. The majority (70.2 percent) of GBCA exposures occurred during the first trimester, which was a 4.3-times greater number than in the second trimester and a 5.1-times greater number versus the third trimester.
"This study identified higher rates of GBCA exposure during the first few weeks of pregnancy compared with the later weeks of pregnancy, suggesting inadvertent exposure to GBCAs might occur before pregnancy is recognized," the authors write.