[Iodinated contrast in pregnant women and neonatal thyroid function]

There is a theoretical risk for neonatal hypothyroidism after prenatal exposure to iodinated contrast media. Current recommendations are in favour of neonatal thyroid function assessment. Our aim was to check if recommendations were observed, and if neonatal evaluation demonstrated anomalies.

Over the period from 01/01/2010 to 01/08/2015, maternal and newborn records were retrospectively reviewed. All pregnant women who underwent a computed tomography and their newborns were included. We collected thyroid-stimulating hormone (TSH), thyroxine (T4) and tri-iodothyronine (T3) levels.

A total of 101 maternal and newborn records were reviewed. Mean gestational age at CT scan was 29.3±7.2 weeks. The mean dose of total iodine administered was 82.6±19.1mL. Only 21 newborns had a biological analysis (20.8%). All newborns had normal TSH and T4 levels at birth. Only 7 newborns had a T3 level above the upper threshold value, but according to expert opinion none have been considered pathological.

Our study revealed that recommendations for neonatal thyroid function assessment after prenatal exposure to iodinated contrast media were not observed. This exposure seemed unlikely to have an important effect on thyroid function at birth.