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

In individuals with type 1 or 2 diabetes mellitus (DM), pre-pregnancy BMI and gestational weight gain (GWG) predicts mode of delivery but not neonatal outcomes. (#115)

Lucy Wang 1 , Renuka Shanmugalingam 2 3 4 , Vincent Wong 4 5
  1. Obstetric Medicine, Liverpool Hospital, Sydney, NSW, Australia
  2. Renal Medicine, Liverpool Hospital, Sydney, NSW, Australia
  3. School of Medicine, Western Sydney University, Sydney, NSW, Australia
  4. South West Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia
  5. Diabetes and Endocrine Service, Liverpool Hospital, Sydney, NSW, Australia

Background: Inadequate or excessive GWG is associated with adverse maternal and neonatal outcomes. The 2009 revised Institute of Medicine (IOM) guidelines recommend GWG targets based on pre-pregnancy BMI. Women with pre-existing type 1 or 2 DM have distinct cardiometabolic risk profiles, making standard GWG recommendations potentially unsuitable for this population.

 

Aim: To assess whether pre-pregnancy BMI and GWG in women with pre-existing DM predicted maternal or neonatal outcomes.

 

Methods: This prospective cohort study enrolled pregnant individuals with pre-existing type 1 or 2 DM, aged over 18 years, who were seen in the Liverpool Hospital antenatal endocrine clinic. Baseline and follow-up data were collected from January 2019 to June 2025. Pregnancy loss <20 weeks and non-singleton pregnancies were excluded.

 

Results: 225 participants were included in final analysis, the mean age was 33.0 (±5.2) years. After adjusting for potential confounders, higher pre-pregnancy BMI was associated with an increased incidence of Caesarean-section (standardised  b .011;p=.009 (95% CI .003,.019). Earlier gestation at delivery was strongly associated with need for NICU admission (standardised  b -.087;p=<.001 (95% CI -.133,-.040), however GWG was not. GWG was not associated with rates of neonatal mortality, hypoglycaemia, birth trauma, jaundice or congenital abnormalities.

 

Conclusion: Although gestational weight gain was not associated with neonatal outcomes, a higher pre-pregnancy BMI was a significant predictor of Caesarean section in patients with pre-existing DM.