Factors affecting thyroid functions in newborns

In this study, it was aimed to investigate the adequacy of iodine level in the nutritional fluid in newborns who were given total parenteral nutrition fluid, and also the effects of gestational week, body weight and gender characteristics on TSH, free T4 and iodine levels were investigated. 30 newborns who were born at 28 weeks or more and hospitalized in Fırat University Medical Faculty Neonatal Intensive Care Unit were included in the study. Each of the newborns had received TPN for at least five days. 1.3 mcg/kg/g iodine is added to TPN fluids in routine neonatal intensive care practice. Urine iodine levels were obtained from the patients before and after TPN and compared. In addition, its effect on serum TSH, free T4, and thyroglobulin levels was investigated. The mean birth week of the patients included in the study was determined as 33.5 ± 4.17 weeks, body weight as 2020.83 ± 834.55 g, and the time they received TPN as 11.47 ± 5.13 days. 24 (%80) of the patients were male and 6 (%20) were female, 23 (%76,7) patients were premature and 7 (%23,3) patients were term delivery. When we examined the effect of our patients birth week, body weight and gender characteristics on TSH, free T4 and iodine levels, no statistically significant difference was found (p> 0.05). When the iodine levels taken before TPN was given, 11 (%36,7) patients had iodine deficiency, 7 (%23,3) patients had sufficient iodine level, and 12 (%40) patients had iodine overload. When iodine levels after TPN were examined, iodine deficiency in 13 (%43,3) patients, sufficient iodine level in 4 (%13,4) patients and iodine overload in 13 (%43,3) patients were found. There was a decrease in urinary iodine levels of patients who received TPN and then started enteral feeding, but it was observed that this was not statistically significant and did not affect thyroid function tests. Keywords: Urine iodine level, parenteral nutrition, newborn