Endocrine Abstracts

JOINT1508

Introduction: Following delivery, insulin sensitivity doubles, and breastfeeding further lowers insulin needs, increasing the risk of severe maternal hypoglycaemia [1], particularly with prior hypoglycaemia unawareness [2]. This case describes a 28-year-old woman with uncontrolled type 1 diabetes (T1D) in early pregnancy, where tight glycaemic control during gestation led to fatal postpartum hypoglycaemia.

Case Presentation: The patient’s pre-pregnancy HbA1c level was >10%, decreasing to 7.1% by 13 weeks of gestation and further to 5.7% at 31 weeks. Treatment with daily subcutaneous injections of insulin degludec and ultra-fast-acting insulin aspart was continued at the woman’s request. At 31 weeks of gestation, the woman’s continuous glucose monitor (CGM) indicated normoglycaemia 81% of the time, hyperglycaemia 20%, and hypoglycaemia 9%. Delivery at 37 weeks of gestation was uneventful, a healthy preterm infant weighing 2355 grams was born. The patient began breastfeeding promptly after delivery. Within 24 hours after delivery, the woman was found unconscious and without vital signs. CGM recorded hypoglycaemia at 2.2 mmol/l and later as low as 0.1 mmol/l. Prolonged hypoglycaemia likely contributed to altered consciousness, acute respiratory failure, and subsequent cardiac arrest.

Discussion: Guidelines from the American Diabetes Association and the National Institute for Health and Care Excellence recommend achieving a HbA1c level <6.5% before conception [3]. Poor glycaemic control and altered insulin sensitivities during pregnancy increase the risk of hypoglycaemia unawareness. Additionally, sudden changes in diabetes control can significantly impact pregnancy outcomes, increasing the risk of maternal and neonatal complications [4].

Conclusion: This case highlights the importance of pregnancy planning for women with T1D and hypoglycaemia unawareness, particularly after delivery when insulin sensitivity undergoes dramatic changes.

References: 1. Skajaa GO, Fuglsang J, Knorr S, Møller N, Ovesen P, Kampmann U. Changes in insulin sensitivity and insulin secretion during pregnancy and post partum in women with gestational diabetes. BMJ Open Diabetes Res Care. 2020;8(2):e001728. doi:10.1136/bmjdrc-2020-001728. 2. Boswell L, Perea V, Amor AJ, et al. Impaired hypoglycaemia awareness in early pregnancy increases risk of severe hypoglycaemia in the mid-long term postpartum irrespective of breastfeeding status in women with type 1 diabetes. Endocrinol Diabetes Nutr (Engl Ed). 2023;70 Suppl 2:18-26. doi:10.1016/j.endien.2022.02.023. 3. American Diabetes Association Professional Practice Committee. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2024. Diabetes Care. 2024;47(Suppl 1):S282-S294. doi:10.2337/dc24-S015. 4. Diabetes in pregnancy: management from preconception to the postnatal period. London: National Institute for Health and Care Excellence (NICE); December 16, 2020.