7988 A Case of Spontaneous Pituitary Hemorrhage in Late Pregnancy

Abstract Disclosure: D. Poudyal: None. G.L. Prince: None. Background: Pituitary apoplexy (PA), caused by hemorrhage into the pituitary gland, is rare. The prevalence in pregnancy is also quite rare, with PA complicating 1 in 10,000 pregnancies. PA usually occurs in patients with pre-existing pituitary adenomas. Spontaneous pituitary hemorrhage (PH) causing PA in the absence of a known adenoma or other precipitating factors is less frequently described. Presenting symptoms of PA are non-specific and can pose diagnostic challenges, yet PA must be managed urgently and decisively due to the risk of life-threatening hormonal deficiencies that can ensue. Physiologic changes in pregnancy pose additional challenges in evaluating and managing patients with possible PA. Here we present a case of spontaneous PH during the third trimester of pregnancy in the absence of pre-existing pituitary pathology or known precipitants. Case presentation: A 31-year-old female, G2P1, with an uncomplicated first pregnancy, presented with acute-onset headache and vision loss at 36 weeks gestation. Her symptoms resolved spontaneously in 45 minutes. MRI brain without contrast showed hemorrhage within the left aspect of the pituitary gland, a mildly displaced infundibulum, but no mass effect on the optic chiasm. MRI brain obtained 1 year prior for headache was unremarkable. Lab work showed an 8AM cortisol of 19 ug/dL (Ref range 3.7 - 19.4 ug/dL), and a total T4 of 11.3 ug/dL (Ref 4.9 - 11.7 ug/dL). Ultimately, interpretation of her cortisol testing was limited by: elevated cortisol-binding globulin in the high-estrogen state of pregnancy, elevated cortisol production by an intact hypothalamic-pituitary-adrenal (HPA) axis during the latter portion of pregnancy, and the lack of validated cutoff values for 8AM serum cortisol levels during pregnancy. In light of these factors and the risk of undiagnosed adrenal insufficiency (AI), she was treated empirically with oral hydrocortisone. Subsequently, she had an uneventful vaginal delivery, supported by stress dosing of her steroids. Postpartum, she had a normal 8AM cortisol level of 14 ug/dL, and she was noted to quickly begin breastfeeding without incident. Conclusion: PA remains a critical diagnosis that cannot be missed in patients presenting with concerning symptoms and signs, in order to identify and treat life-threatening hormonal deficiencies. Pregnancy poses unique challenges in diagnosing hormonal deficiencies such as AI due to normal physiologic changes affecting the HPA axis as well as other pituitary axes. Therefore, the benefit of empiric hydrocortisone treatment likely outweighs any associated treatment risk in cases with consistent symptomatology and radiographic findings. Presentation: 6/2/2024