Effects of topical povidone-Iodine on thyroid functıon in surgical newborns

INTRODUCTION: Excessive iodine exposure during the neonatal period can lead to neonatal hypothyroidism due to their thinner and more permeable nature of skin. This study was conducted to evaluate the effects of povidone-iodine on postoperative thyroid functions among surgical neonates.
METHODS: Surgical neonates with known preoperative and postoperative thyroid function tests who had been operated by our department between January 2014-2016 were included this study. The postoperative thyroid function tests of these neonates were obtained between postnatal 7-21th days. Preoperative and postoperative measurements of free Thyroxine 4 and Thyroid Stimulating Hormone levels were analyzed retrospectively.
RESULTS: Nineteen male and fourteen female surgical neonates were included in this study. Their mean gestational age and age at operation were 37weeks+1day and 10 days. Mean duration of hospitalization was 12.6 days and mean number of dressings per day during hospitalization was one. Mean preoperative and postoperative values of free Thyroxine 4 and Thyroid Stimulating Hormone were 1.12mIU/L, 1.14mIU/L, 6.1 mIU/L and 2.77mIU/L, respectively.
During the postoperative period, free Thyroxine 4 values mildly increased and Thyroid Stimulating Hormone levels decreased, however, all values remained within reference values. The change in Thyroid Stimulating Hormone levels between preoperative and postoperative periods was statistically significant. Patients did not require thyroid hormone replacement therapy.

DISCUSSION AND CONCLUSION: Although not necessitating hormone replacement therapy, the use of topical povidone iodine significantly and transiently affects the thyroid functions of surgical neonates due to transdermal iodine absorption.