Endocrine Abstracts

A preterm baby was born at 23 weeks + 2 days gestation. She was managed on our tertiary care neonatal unit and remained ventilated for most of her stay.

During her admission, she had recurrent episodes of clinically suspected NEC which were medically managed. Her feeds were discontinued on numerous occasions due to bilious aspirates, vomiting and abdominal distention. Given the patient’s clinical condition, a contrast study of the gastrointestinal tract was done using an enteral iodinated contrast agent to exclude a stricture.

She also developed ascites and needed 4 radiologically-inserted drains. No underlying cause was found for her ascites, which spontaneously resolved over a period of 2 weeks.

Her thyroid function had been normal; however, further testing 5 days following the ingestion of the iodine-containing contrast agent revealed a markedly elevated TSH (>500 mU/L) with free T4 <5.2 pmol/L.   Due to intestinal failure, treatment with IV levothyroxine was required. This was gradually reduced and then stopped as the patient’s TFTs normalised.

This case demonstrates the harmful effect of iodine-containing, radiologic contrast media on thyroid function, and the potential risks of using these contrast media in neonates with suspected intestinal failure. Intestinal failure in this case prolonged the time of exposure to the oral contrast agent.

It reinforces the recent FDA-approved warning to the prescribing information for the entire class of iodinated contrast media injections and monitoring recommendations for children 3 years or younger. This FDA warning was posted in March 2022 and is available @ https://www.fda.gov/safety/medical-product-safety-information/iodine-containing-contrast-media-drug-safety-communication-fda-recommends-thyroid-monitoring-babies

In addition, this case also demonstrates the rare need for treatment with IV levothyroxine, as the patient was not absorbing any enteral medications or feeds, secondary to intestinal failure.