Iodinated Contrast Induced Hypothyroidism in the Infant After Enteral Contrast Enema: A Case Report and Systematic Review

Background: Excessive iodine intake triggers the Wolff-Chaikoff effect resulting in downregulation of thyroid hormone synthesis to prevent hyperthyroidism. Failure to escape the Wolff-Chaikoff effect can be seen especially in (premature born) infants and may result in prolonged iodine induced hypothyroidism. We describe a rare case of a preterm infant who developed severe iodinated contrast induced hypothyroidism after the use and prolonged stasis of enteral iodinated contrast media (ICM). In addition a systematic literature search was performed to evaluate all available data on this complication.
Methods: A systematic literature search was performed in PubMed and Embase. Studies describing the effect of enteral ICM on thyroid function were considered eligible. The primary outcome was to determine the frequency of contrast induced hypothyroidism in infants after administration of enteral ICM.
Results: The premature infant in our center developed severe iodinated contrast induced hypothyroidism after enteral ICM. In total, only two studies met our eligibility data, reporting eight patients. Out of these eight patients, four premature infants developed a contrast induced hypothyroidism after enteral administration of ICM.
Conclusion: Data on severity, length and frequency of contrast induced hypothyroidism after exposure to enteral ICM is very scarce. The herein reported case and literature search illustrate the potential severity of the complication and underline the necessity of future studies on this topic. We recommend standardized monitoring of thyroid function after exposure to enteral ICM in newborns to prevent delayed diagnosis of severe contrast induced hypothyroidism until evidence based recommendations can be made.