Safety of Contrast Material Use During Pregnancy and Lactation

Key points

Overview

Radiological examinations are infrequently performed for nonobstetric conditions during pregnancy to avoid exposure of the fetus to ionizing radiation in the case of radiographs and CT or the potentially harmful effects of gadolinium in MR imaging. However, the number of imaging studies in this group of patients has doubled over the past decade in the United States, with an actual increase rate of 107%.¹ The leading indications for obtaining imaging studies in patients who are pregnant are

Iodinated contrast agents

Imaging of women who are pregnant has recently increased, as demonstrated by Lazarus and colleagues¹ who observed an increased rate of 107% of radiological studies in pregnant women between 1997 and 2007. The imaging modality that was used the most was CT, especially chest CT, which often entails the use of iodinated contrast media.

Gastrointestinal contrast media

Barium agents are non–water soluble positive contrast media that attenuate radiographs. They consist of a suspension of insoluble barium sulfate particles that are not absorbed from the gut.³² Radiological studies using barium are not usually performed during pregnancy because of the risk of exposure to ionizing radiation to the fetus. Most of these studies have been done inadvertently in women during early pregnancy.³³

In 2011, Han and colleagues³³ evaluated 32 women exposed to barium sulfate

Contrast-enhanced ultrasound

Ultrasound contrast agents (USCAs) produce their effect by increasing back-scattering of sound compared with that from native blood and tissues. USCAs for IV injections are usually gas-filled microbubbles with a mean diameter less than that of a red blood cell.⁴⁸ Microbubble size and uniformity are of prime importance in ensuring its nontoxicity, as those smaller than 10 μm in diameter are not trapped within the capillary vasculature, reducing the risk of microembolism.⁴⁹ In Europe, only 2 of

Management of allergic reactions in patients who are pregnant or lactating

Once it has been determined that a patient who is pregnant has had a reaction to a contrast agent, this reaction should be classified as mild, moderate, or severe according to ACR guidelines.³ Some early symptoms and signs of an anaphylactic response during pregnancy are intense vulvar and vaginal itching, low back pain, uterine cramps, fetal distress, and preterm labor.⁶⁰

Summary

Different types of contrast agents are used according to the imaging modality. When they are administered to patients who are pregnant or lactating, special considerations need to be taken into account. Iodinated contrast media are considered safe for mothers and newborns. To date, no data suggesting any potential harm to the fetus have been reported. There is no need to stop breastfeeding after the administration of such contrast agents.

Barium sulfate has not demonstrated to be teratogenic or