Poster Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

Impact of pre-pregnancy bariatric surgery on maternal glucose profiles in pregnancy (127373)

Jade Eccles-Smith 1 2 , David McIntyre 3 4 , Marloes Dekker Nitert 5 , Helen L Barrett 6 7
  1. Mater Medical Research Institute, South Brisbane, QLD, Australia
  2. Obstetric Medicine, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
  3. Obstetric Medicine, Mater Health Services, South Brisbane, QLD, Australia
  4. School of Medicine, The University of Queensland, Herston, QLD, Australia
  5. School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
  6. Obstetric Medicine, Royal Hospital for Women, Randwick, NSW, Australia
  7. Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia

Maternal pre-pregnancy bariatric surgery is associated with fewer obesity-related pregnancy complications but increased risk of small for gestational age infants and challenges in glucose assessment.[1] This prospective observational cohort study compared mid-pregnancy glycaemic patterns using continuous glucose monitoring (CGM) between women with and without prior bariatric surgery.

We recruited n=20 women with a history of bariatric surgery and n=16 age-matched controls before 24 weeks' gestation. Participants wore blinded CGM devices for 14 days between 24–29 weeks’ gestation. Key CGM metrics included time in range (pTIR, 3.5–7.8 mmol/L), time below range (pTBR, <3.5 mmol/L), time above range (pTAR, >7.8 mmol/L), mean glucose, and glycaemic variability (coefficient of variation, CV). Descriptive statistics were reported using medians with interquartile ranges, and group comparisons were made using independent t-tests or Wilcoxon rank-sum tests.

CGM data were available for n=18 women with pre-pregnancy bariatric surgery and n=13 controls. The bariatric group had a median age of 32.0 (27.5, 36.0) years and BMI of 31.6 (28.5, 34.4) kg/m² versus 33.0 (30.5, 34.5) years and 23.7 (21.5, 25.8) kg/m² in controls. There were no significant differences in pTIR, pTBR, pTAR, mean glucose, or CV between groups (all p > 0.05). However, a trend toward increased glycaemic variability was observed in the bariatric group.

In conclusion, although CGM metrics did not differ significantly, the observed trend could suggest greater glucose variability in women with prior bariatric surgery. Further comparisons in BMI-matched groups are warranted to explore CGM's potential as an alternative glucose assessment method in this population.

  1. Eccles-Smith, J., et al., Pregnancy and offspring outcomes after prepregnancy bariatric surgery. Am J Obstet Gynecol, 2025. 232(5): p. 485.e1-485.e9.