Background: The proportion of newborns recalled during neonatal screening programs for congenital hypothyroidism (CH) varies substantially by country and may be higher in settings where povodine iodine (PVP-I) is used during delivery. We assessed this hypothesis by substituting PVP-I for chlorhexidine (CHL) and evaluated the reduction in the recall rate of the Irainian newborn screening program.
Methods: This study investigated 2282 neonates of mothers admitted to a local hospital for delivery between December 2012 and October 2013. We measured thyorid stimulating hormone (TSH) levels in heel-prick blood specimens of infants, aged between 3 and 5 days, born to mothers who received PVP-I (phase I) and those who received CHL after withdrawal of PVP-I from obstetric procedures (phase II). Then we compared the median TSH levels and the recall rate based on a TSH level ≥5 mU/L.
Results: Of 2282 cases, 1094 infants were born to mothers exposed to PVP-I during phase I (PVP-I group) and 1188 ones were born to mothers exposed to chlorhexidine in phase II (CHL group); 6.56% of the PVP-I group and 1.91% of the CHL group were recalled later during screening (p<0.001). The median TSH level was significantly higher in the PVP-I group compared to the CHL group (1.35 vs. 1.00, p<0.001).
Conclusions: Replacement of iodine-containing antiseptics by iodine-free ones, during delivery resulted in a significant reduction in the recall rate of the Iranian screening program for CH.
Keywords: congenital hypothyroidism; endocrinology-pediatric; iodine; thyroid function.