Outcome of a baby born from a mother with acquired juvenile hypothyroidismhaving undetectable thyroid hormone concentrations

We report a baby born from a mother with strongly positive thyroid stimulat ion blocking antibody (TSBAB) and nearly undetectable T-4 level. This case is a unique model of nearly complete absence of thyroid hormones during fet al and early neonatal life in humans. The infant girl was born by cesarean section, because of fetal bradycardia, after 41 weeks gestation and receive d mechanical ventilation for 3 days. The TSH level was more than 120 mu U/m L in the neonatal thyroid screening. At age 17 days, the results of a thyro id function study showed undetectable free T-3 and free T-4 concentrations, TSH 550 mu U/mL, and TSH receptor antibody (TRAB) 87%. Thyroxine at a dose of 30 mu g/day was started at age 17 days. The patient required thyroxine treatment until age 8 months. The brain magnetic resonance image at age 2 m onths revealed reduced brain size. Her auditory brain stem response was abs ent at age 2 months. The audiogram at age 4 yr revealed sensorineural deafn ess of 70 dB. When she was 6 yr of age, motor development remained the same as that at age 4 months. Her height was 106 cm (-1.5 SD). The results of t hyroid function study of the mother 23 days after delivery showed undetecta ble free T-3 and free T-4, TRAB 84%, and TSBAB 83%. In conclusion, the outc ome of severe thyroid hormone deficiency in utero and early in human neonat al life was normal physical growth, fetal distress resulting in cesarean se ction, difficulty in the onset of breathing, permanent deficit in auditory function, brain atrophy, and severely impaired neuromotor development despi te the start of an adequate dose of thyroxine replacement during the neonat al period.