Abnormal pubertal development in primary hypothyroidism

We have studied three patients (1M, 2F), age range 10.9 to 15.5 years, who had abnormal sexual maturation secondary to primary hypothyroidism. The boy had inappropriately large testes for his stage of puberty, the girls had isolated breast development and there was absence of pubertal growth acceleration. FSH, LH, TSH and GH secretion, pituitary imaging and ovarian ultrasound morphology were studied before and during thyroxine treatment. In the hypothyroid state, FSH levels were elevated with abnormal pulsatility and LH:FSH concentrations were reversed.