Higher frequency of screening TSH above 5 mIU/l in infants likely exposed to higher doses of iodine-containing skin antiseptic: implications for assessment of iodine sufficiency.

BACKGROUND

Neonatal TSH screening has as its main goal the early detection and treatment of permanent sporadic congenital hypothyroidism. At the same time neonatal TSH is one of the indicators for monitoring progress towards eliminating iodine deficiency disorders (IDD).

AIM

To evaluate the usefulness of neonatal TSH screening data as a monitoring tool for IDD evaluation and control in Bosnia and Herzegovina.

INFANTS AND METHODS

The study included a total of 8,105 newborns. Neonatal TSH was measured in whole blood drawn between day 3 and day 5 of life, spotted on filter paper using a sensitive fluorometric assay (Delfia).

RESULTS

Levels above 5 mIU/l were found in 282 (5.5%) neonates. Median TSH values and the percentage of samples of neonatal TSH above 5 mIU/l were significantly higher in neonates who were born by Caesarean section (6.4%) compared with neonates born by vaginal delivery (1.4%).

CONCLUSION

Our findings suggest that neonatal TSH should not be used as a monitoring tool for IDD evaluation and control if iodinated skin disinfectant is used on a large part of the mother's skin in maternity hospitals.