ADIPS Poster Presentation Australasian Diabetes in Pregnancy Society and Society of Obstetric Medicine Australia and New Zealand Joint Scientific Meeting 2025

Mitigating Hypoglycaemia: Rethinking GDM Screening in Bariatric Surgery Patients (#101)

Ashni Goshrani 1 2 , Quoc Vinh Hong 2 , Michele Bardin 2 , Jas-mine Seah 2 3 4
  1. Department of Endocrinology, Royal Melbourne Hospital, Melbourne, VIC, Australia
  2. Department of Endocrinology, Northern Health, Melbourne, VIC, Australia
  3. Department of Endocrinology, Austin Health, Melbourne, VIC, Australia
  4. University of Melbourne, Melbourne, VIC, Australia

Background: Gestational diabetes mellitus (GDM) is commonly screened using a 75g oral glucose tolerance test (OGTT). In patients with prior bariatric surgery, the OGTT may trigger dumping syndrome, leading to hypoglycaemia and neonatal risks1.

Aims: This audit aimed to evaluate the incidence of GDM, diagnostic methods, and rates of OGTT-related hypoglycaemia in this population at a tertiary hospital in Melbourne.

Methods: This observational, retrospective audit spans from 2014 to 2023. A total of 121 patients from the Obesity in Pregnancy clinic, all with a history of bariatric surgery, were included. Patients without bariatric surgery or with type 2 diabetes were excluded. Data on demographics, type of bariatric surgery, hypoglycaemia episodes, and maternal and neonatal outcomes were collected.

Results: GDM was diagnosed in 32 of 121 patients (26.4%). The OGTT was the most common diagnostic method (45.5%), followed by fasting plasma glucose and self-monitoring of blood glucose. Hypoglycaemia (≤3.5 mmol/L) related to the OGTT occurred in 29.1% (16/55) of cases. Gastric sleeve was the most common bariatric procedure, followed by gastric banding.

Conclusion: The GDM rate among patients with prior bariatric surgery in this cohort is higher than in other observational studies (7-16%)2,3. Despite the risks of dumping syndrome and hypoglycaemia, the OGTT remains the most common testing method. We are currently conducting a prospective study to determine the optimal diagnostic approach for this population and to develop appropriate guidelines.

  1. 1. Rottenstreich A, Elazary R, Ezra Y, Kleinstern G, Beglaibter N, Elchalal U. Hypoglycemia during oral glucose tolerance test among post–bariatric surgery pregnant patients: Incidence and perinatal significance. Surgery for Obesity and Related Diseases. 2018;14(3):347-353.
  2. 2. Benhalima K, Minschart C, Ceulemans D, et al. Screening and management of gestational diabetes mellitus after bariatric surgery. Nutrients. 2018;10(10):1479.
  3. 3. Sesilia K, Susanna P, Virve K, Mika G, Veli-Matti U, Marja K. The outcome of pregnancies after bariatric surgery: an observational study of pregnancies during 2004–2016 in Finland. Archives of Gynecology and Obstetrics. 2023;307(5):1599-1606.