ODP332 Maternal Central Diabetes Insipidus Immediately after Delivery, Owing to Vasospasm of the Internal Carotid Artery

BACKGROUND: Sheehan's syndrome is a cause of hypopituitarism during the postpartum period, but it rarely manifests immediately after birth. CLINICAL CASE: We report the case of a 30-year-old woman who delivered her second child, lost 1,050 mL of blood in the process, but did not receive a blood transfusion. A few hours after delivery, the patient complained of headache, nausea, and thirst, and her urine production increased to 9 L/day. No menstrual irregularities or abnormalities during pregnancy or childbirth had been reported. None of hypotension, external eye muscle paralysis, or visual impairment were identified on physical examination. The laboratory findings were low urine osmolality and high serum osmolality and sodium concentration. The concentrations of thyroid hormones, growth hormone (GH), and anti-diuretic hormone (ADH) were found to be low. The IgG4 concentration was not high (4.7 mg/dL; normal <105 mg/dL) and the patient was negative for anti rabphilin-3A antibody. Pituitary magnetic resonance imaging (MRI) on the day of admission showed enlargement of the pituitary gland and stalk, and magnetic resonance angiography showed stenosis of the left internal carotid artery. The patient showed a poor response to GH-releasing peptide 2 and thyroid releasing hormone stimulation. Hypertonic saline administration did not cause an increase in ADH concentration. We diagnosed adult growth hormone deficiency (aGHD), central hypothyroidism, and central diabetes insipidus (DI). The enlargement of the pituitary gland was slightly less marked and the stenosis of the left internal carotid artery improved 7 days after admission. After 6 months, the pituitary gland was almost normal in size, although the aGHD, central hypothyroidism, and central DI remained. Sheehan's syndrome or lymphocytic hypophysitis could have been responsible for the postpartum hypopituitarism. This case was not typical of lymphocytic hypophysitis with respect to the hormone deficiency pattern, the MRI findings, and the lack of anti rabphilin-3A antibody. Sheehan's syndrome is caused by ischemic necrosis of the anterior pituitary gland after severe postpartum hemorrhage. The prevalence of central DI is estimated to be 2%–3%. Typically, pituitary dysfunction progresses slowly and develops several years after childbirth. In contrast, in the present patient, stenosis of the left internal carotid artery developed and improved during short periods of time. The vasospasm of the internal carotid artery caused reductions in flow through the superior and inferior hypophysial arteries, which resulted in ischemia and necrosis of the pituitary gland, similar to Sheehan's syndrome. Clinical Lesson: Although rare, maternal central DI can be caused by ischemia and vasospasm immediately after the delivery of a child. The possibility of a pituitary stroke in the presence of neoplastic disease should not be ruled out, and imaging and pituitary gland function should be followed over the long term. Presentation: No date and time listed