Transient hypothyroidism in the newborn infant

Abstract

NEONATAL SCREENING for congenital hypothyroidism is important because of the possibility that mental retardation may be avoided if treatment is started early.' The diagnosis rests on the detection of a high serum level of TSH and low T, during the first few days of life. Whether the presence of these biochemical signs soon after birth necessarily indicates permanent thyroid insufficiency is unknown. Recent data suggest that, in some circumstances, thyroid insufficiency may be transient. Premature infants with respiratory distress have low T4 and T~ levels associated with high TSH levels in cord blood, 2 but these abnormalities revert progressively.:* Furthermore, preliminary data' show a temporary drop in serum T4 values in some premature infants admitted to an intensive care unit. Herein we discuss six infants in whom thyroid insufficiency was detected in the early days of life and disappeared spontaneously after a few weeks. PATIENTS The six infants, five of them premature, were admitted to the neonatal intensive care unit for different serious conditions (Table I). In Patients 2 to 6 abnormal thyroid function was suspected on the basis of high serum TSH values on the fifth day of life) and in Patient 1 because of thyroid hyperplasia detected on the forty-fifth day.