SAT-466 Late Diagnosis Of Nonclassical Congenital Adrenal Hyperplasia In A Female With Infertility: A Case Report

Abstract Disclosure: C.M. Ramos Moreno: None. V.F. Moore Reyes: None. B.V. Prieto Castillo: None. P.S. Duron Medina: None. E. Mendez: None. N.H. Shaaban: None. Background: Nonclassical congenital adrenal hyperplasia (NCCAH) is a milder form of congenital adrenal hyperplasia caused by 21-hydroxylase deficiency. It presents later in life with signs of hyperandrogenism, such as irregular menses, hirsutism, and infertility. Due to clinical overlap with polycystic ovary syndrome (PCOS), it is often misdiagnosed, especially when initial laboratory evaluation is limited to ovarian-focused studies without assessing adrenal function. When standard PCOS treatments fail, NCCAH should be considered, as its management and follow-up differ significantly. Clinical Case: A 32-year-old woman with a history of prediabetes and oligomenorrhea presented for endocrine evaluation after one year of infertility and elevated androgen levels. She had previously been diagnosed with PCOS based on irregular cycles and mild hirsutism. Initial labs revealed elevated DHEA-S, mildly elevated total and free testosterone, and elevated 17-OHP level (698 ng/dL). A dexamethasone suppression test showed persistent cortisol and DHEA-S elevation. Due to suspicion of NCCAH, a cosyntropin stimulation test was performed, confirming the diagnosis with 17-OHP levels of 1051 ng/dL. She was started on hydrocortisone 15 mg daily, leading to spontaneous conception within weeks. After pregnancy confirmation, her therapy was transitioned to a physiologic dose of prednisone 7.5 mg daily. The plan included monitoring pregnancy progression, testing the newborn for 21-hydroxylase deficiency, and adjusting therapy postpartum. Conclusion: This case emphasized the importance of thorough endocrine evaluation in women with infertility and hyperandrogenism. Early differentiation between PCOS and NCCAH is critical, as management strategies and reproductive outcomes differ. Adrenal-focused testing in the initial workup of atypical PCOS presentations can prevent delayed diagnosis and improve fertility outcomes. Presentation: Saturday, July 12, 2025