Post-bariatric hypoglycaemia diagnosed during pregnancy.

Summary: There is a scarcity of literature relating to post-bariatric hypoglycaemia (PBH) in pregnancy. Recurrent hyperglycaemia and hypoglycaemia can have significant consequences for both the mother and the developing fetus. We describe a case of a young pregnant woman who was diagnosed with symptomatic PBH in the second trimester of pregnancy using continuous glucose monitoring (CGM) 3 years after Roux-en-Y gastric bypass (RYGB) surgery. Instigating a low glycaemic index and complex carbohydrate diet significantly improved the patient's glycaemic excursions. Given that this condition is likely underdiagnosed as a complication of RYGB surgery, a greater awareness of this complication is needed. Patients should be adequately consented pre-operatively for this relatively frequent late surgical complication to enable patients to identify symptoms of this condition at an early stage and seek medical treatment.

Learning points: PBH is an important diagnosis in patients post-RYGB surgery, particularly in women of childbearing age when consequences of both hyperglycaemia and hypoglycaemia during pregnancy can adversely affect both mother and the fetus. Adverse outcomes of recurrent hypoglycaemia to the fetus can include small for gestational age, intrauterine growth restriction and possible impairment of beta cell function. Providing adequate carbohydrate intake to allow growth of the fetus during pregnancy while also attempting to resolve both hyperglycaemia and hypoglycaemia associated with PBH by reducing the intake of simple carbohydrates and high glycaemic index foods can prove challenging. Patients should be adequately consented for late complications of RYGB surgery such as PBH in order to allow early recognition of symptoms and enable prompt treatment.