Abstract
Two children aged 1 and 20 months developed alveolar hypoventilation syndrome. They suffered severe apnoeic episodes and periodically required assisted ventilation. Their ventilatory response to carbon dioxide was lower than that of normal children and the transcutaneous oxygen tension during sleep was well below the normal range. Treatment with medroxyprogesterone acetate resulted in an improved response to carbon dioxide, and assisted ventilation was no longer needed. Oxygen and carbon dioxide tensions improved but were still slightly abnormal during sleep. There were no clinical side effects of treatment but one infant had slight pituitary suppression.