Iodine Status and Thyroid Functions of Turkish and Syrian Mother-Newborn Dyads in a County of Istanbul

Abstract

Background: Inappropriate iodine intake can result in thyroid disorders in mothers and newborns in addition to their adverse effects on prenatal and postnatal developmental processes. Determination of median urinary iodine concentration (MUIC) is an established tool for monitoring of iodine nutrition. Aim: The aim of this cross-sectional study was to investigate iodine status by measuring the MUIC and serum TSH and free T4 levels of Turkish and Syrian mother-newborn dyads in a county of Istanbul. Methods: In a tertiary care center, in the Turkish and Syrian, low-risk, term-pregnant mothers and their newborns, urine samples were collected from mothers and newborns within first 24 hours after birth. For the measurements of TSH and free T4, blood samples were obtained from mothers at admission to labor and delivery unit and from newborns on day 5 of neonatal life. Results: In the study population of mothers, mild iodine deficiency was more prominent with an incidence of about 18%, followed by moderate and severe forms with an incidence of about 5% and 0.5%, respectively. Turkish and Syrian mothers had similar incidence of mild, moderate, and severe iodine deficiencies. The incidence of iodine deficiency of newborns were 41%. Overall, in the Turkish and Syrian participants, there were no prominent correlations between the MUICs of mothers and newborns. Regarding serum TSH and free T4 levels, the median TSH concentration of Turkish mothers was significantly lower (p 0.05). Considering TSH values of newborns, in 40 of them, there was higher TSH values requiring attention during neonatal follow-up. They had mild and moderate but not severe form of TSH elevation. Conclusion: Despite the mandatory salt iodization and official health care support for all mothers and newborns, daily iodine supplementation during pregnancy and breastfeeding seems to be a helpful measure to prevent the adverse effects of iodine deficiency to newborns and children. Funding Statement: This study was supported by a grant of Turk Pediatri Kurumu Dernegi (the Association of Turkish Pediatrics Institution). The content is solely the responsibility of the authors and does not necessarily represent the official views of the Association of Turkish Pediatrics Institution. Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: The study was approved by the Human Research Ethics Committee (Registry No. 464). All participants provided written informed consent.