Challenges in Managing Pregnancy in Patients With Fructose 1, 6-Bisphosphatase Deficiency: A Single-Centre Experience

Fructose-1,6-bisphosphatase deficiency is a rare inherited metabolic disorder of gluconeogenesis characterized by recurrent hypoglycemia and lactic acidosis, typically triggered by inadequate glucose intake or increased consumption of fructose, sucrose, or sorbitol. During pregnancy, the risk of hypoglycemia and lactic acidosis increases because endogenous glucose production is limited while fetal glucose demand rises. Here we report three patients with fructose-1,6-bisphosphatase deficiency who had successful pregnancies and deliveries. These patients were managed by a multidisciplinary team of obstetricians, maternal-fetal medicine specialists, metabolic physicians, and metabolic dieticians. All patients were obese; one had morbid obesity. Two patients developed gestational diabetes mellitus. One responded to dietary intervention, whereas the patient with morbid obesity had poor dietary adherence, suboptimal glycemic control, and experienced an episode of severe life-threatening hypoglycemia with lactic acidosis requiring intensive care. She recovered fully, with no adverse maternal or fetal effects. All patients had normal vaginal deliveries and were closely monitored during labor, delivery, and the postpartum period. Both patients with gestational diabetes developed lactic acidosis immediately after delivery despite stable blood glucose levels. Managing gestational or type 2 diabetes in patients with fructose-1,6-bisphosphatase deficiency is particularly challenging because the disorder predisposes them to hypoglycemia. This case series contributes to the limited literature on pregnancy outcomes and highlights key management challenges in this rare condition.