[Neonatal hyperthyroidism in non-diagnosed Basedow's disease of the mother. Problems of diagnosis and therapy illustrated by a case history].

A male preterm infant (born at 34 weeks, birth weight 2130 g) developed jaundice (total bilirubin 7.4 mg/dl), hepatosplenomegaly, thrombocytopenia (82,000/microliters) and a raised C-reactive protein (1.2 mg/dl). Although sepsis was suspected, no organism was demonstrated. When the mother visited the child for the first time after 2 weeks, she had florid hyperthyroidism. This explained many of the child's clinical features (poor weight gain, tachycardia, exophthalmos). Both mother and child had raised TSH receptor antibodies (mother: 684.6 U/l; 54.1 U/l, normal < 15 U/l), an increased free T4 and a suppressed TSH. Because of the tachycardia, the child was treated with propranolol (1 mg/kg.d for 5 weeks). He was also initially given Lugol's solution (25 mg iodide/kg.d for 1 week) and then propylthiouracil (7 mg/kg.d) because of the increasing total T3. L-Thyroxine replacement was subsequently required for a period of 2.5 weeks because of treatment-related hypothyroidism. Since stopping treatment (at 12 weeks of age), the child has developed normally.--Neonatal hyperthyroidism due to transplacental transfer of TSH receptor antibodies associated with maternal Graves' disease is a rare self-limiting condition. However, it may pose considerable danger to the child both in utero and postnatally (with a mortality if untreated of up to 20%). Interdisciplinary cooperation is essential.