Evaluation of the effect of maternal iodine status on recall frequency in newborn TSH screening

Objective: Pregnant and lactating women are particularly at higher risk of iodine deficiency due to their increased iodine requirements. Iodine is necessary for normal growth and brain development. In regions with moderate iodine deficiency, such as Turkey, the fate of newborn babies is a critical issue.This study evaluated the relationship between maternal iodine deficiency and the frequency of recall due to high TSH value in newborn screening programs. Methods: 78 mothers who volunteered for the research were included in the study with their newborn babies. Thyroid function tests were examined in the blood serum of newborns with high heel blood TSH value (5.5-20mIU/L) who were referred to the pediatric endocrine with the suspicion of congenital hypothyroidism Urinary iodine levels of healthy mothers without any thyroid disease and iodine exposure were evaluated. Results: The median urinary iodine in mothers was 56.04 μg/l. Only 8 (10.2%) of the recalled newborns had subclinical hypothyroidism and recovered at the follow-up 1 week later, while all the rest had normal thyroid functions. In addition, there was a weak negative correlati-on between maternal age, the number of children, and urinary iodine levels (respectively, r=0.35,r= 0.33; p=0.001,p=0.003). Conclusion: Only 9%(7 people) of the mothers participating in the study had adequate urinary iodine excretion and almost half (38 peop-le) of the mothers (48.7%) had severe urinary iodine deficiency. Low maternal iodine values are effective in the prolonging transient TSH elevation in newborns, and iodine supplementation to mothers during pregnancy may reduce recall rates of newborn TSH screening.