Thyroid dysfunction in preterm neonates exposed to iodine

Area of Science:

• Neonatal endocrinology
• Perinatal medicine
• Thyroid function studies

Background:

• Topical iodine avoidance is recommended during pregnancy and breastfeeding for infants under 32 weeks' gestation.
• Preterm neonates often experience exposure to topical iodine and iodinated contrast media.

Purpose of the Study:

• To investigate the impact of intrapartum/neonatal topical iodine and iodinated contrast media exposure on thyrotropin levels in preterm infants.
• To assess potential neonatal thyroid dysfunction following iodine exposure.

Main Methods:

• Recruitment of infants <32 weeks' gestation.
• Recording maternal and neonatal exposure to iodinated contrast media and topical iodine.
• Measuring thyrotropin and thyroxine levels from blood-spot cards at specific postnatal days and 36 weeks' gestation.

Main Results:

• Higher mean thyrotropin levels were observed in infants exposed to topical iodine before cesarean section compared to unexposed infants.
• This association persisted after adjustment for confounding factors.
• Transient hyperthyrotropinemia occurred in three exposed infants; no hypothyroidism was treated.

Conclusions:

• Neonatal thyroid dysfunction was observed following iodine exposure via cesarean section.
• Exposure to iodinated contrast media did not appear to affect neonatal thyroid function in this study.