Continuous Glucose Monitoring (CGM) for Effective Glucose Control in a Pregnant Woman Living with type IIIa glycogenosis. A Case Report.

Background & aims: Glycogenosis type III is a rare autosomal recessive disease caused by a mutation in the AGL gene that results in a deficiency of the glycogen debranching enzyme. This deficiency impairs fasting tolerance and leads to hypoglycemia. While the symptomatology tends to improve with age, pregnancy can trigger a recurrence of hypoglycemia due to increased carbohydrate requirements. Since the late 1990s, continuous glucose monitoring (CGM) has been used in insulin-dependent diabetes to aid in the prevention of hypoglycemia. It has also been employed in type I glycogenosis for the same purpose. However, it has never been evaluated for the prevention of hypoglycemia in pregnant women with type III glycogenosis.

Case: report: We present the case of a 32-year-old pregnant woman with type IIIa glycogenosis diagnosed at the age of 2 years old. The resurgence of nocturnal hypoglycemia initially led to the reinstatement of continuous nocturnal nutrition. We established remote glucose monitoring via CGM, facilitating medical and dietary teleconsultations until delivery. These teleconsultations enabled dietary adjustment according to the patient's needs, based on the CGM data. This subsequently led to a reduction in the frequency and duration of nocturnal hypoglycemia, even after discontinuing continuous nutrition. No severe hypoglycemia was observed.

Discussion: Our results suggest that CGM combined with telemonitoring can provide effective support for individuals living with glycogenosis during pregnancy and may eliminate the need for resuming continuous nocturnal enteral nutrition. However, these results need to be confirmed with additional patient cases.

Conclusion: CGM is a safe tool to limit the risk of hypoglycemia and to improve the quality of life of pregnant patients with type III glycogenosis.