Effects of topical Povidone-iodine on thyroid function in surgical newborns

Abstract

Objective: 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. Material and Methods: Surgical neonates with known pre-operative and post-operative thyroid function tests who had been operated by our department between January 2014 and 2016 were included this study. The post-operative thyroid function tests of these neonates were obtained between postnatal 7th and 21th days. Pre-operative and post-operative measurements of free Thyroxine 4 (fT4 ) and thyroid-stimulating hormone (TSH) levels were analyzed retrospectively. Results: Nineteen male and 14 female surgical neonates were included in this study. Their mean gestational age and age at operation were 37 weeks + 1 day and 10 days. Mean duration of hospitalization was 12.6 days and mean number of dressings per day during hospitalization was one. Mean pre-operative and post-operative values of fT4and TSH were 1.12 mIU/L, 1.14 mIU/L, 6.1 mIU/L, and 2.77 mIU/L, respectively. During the post-operative period, fT4values mildly increased and TSH levels decreased, however, all values remained within reference values. The change in TSH levels between preoperative and postoperative periods was statistically significant. Patients did not require thyroid hormone replacement therapy. 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..