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

Serum proteins and maternal anthropometric measures of obesity, measured in trimester 1 of pregnancy, have value as biomarkers of large-for-gestational age neonates (#180)

Matilda S G Longfield 1 2 , Amanda R Purcell 2 , Daniel Kim 3 , Kushalee P Jayawickreme 1 , Natassia Rodrigo 1 4 5 , Jean Yang 3 , Sarah J Glastras 1 2 5
  1. Diabetes, Metabolism & Endocrinology, Royal North Shore Hospital, Sydney, NSW, Australia
  2. Kolling Institute, University of Sydney, Sydney, NSW, Australia
  3. School of Mathematics and Statistics, The University of Sydney, Sydney, New South Wales, Australia
  4. Department of Endocrinology, Nepean Hospital, Sydney, NSW, Australia
  5. Northern Precinct, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia

Women with gestational diabetes (GDM) have higher incidence of delivering large-for-gestational age (LGA) neonates. However, current clinical diagnosis of GDM commonly occurs between week 24-28, curtailing our capacity to intervene earlier.  

This study aimed to evaluate if serum proteins and anthropometrics differ in women who deliver LGA neonates in trimester 1.

Pregnant women from Royal North Shore Hospital were screened for risk-factors of GDM. Serum samples and anthropometric measures were collected at 14-18 weeks of gestation. Proteomic analysis was done using liquid chromatography mass spectrometry. perinatal outcomes were recorded at delivery and mothers were grouped based on occurrence of LGA with analysis completed in R. Proteins were filtered based on a p<0.05 and a fold-change (FC) threshold of 1.5.

This study included 102 women with an LGA incidence of 20(19.6%). Rates of GDM did not differ between groups. BMI (26.0±6.32kg/m2 vs 32.2±7.45kg/m2, p=0.002), abdominal circumference (93.6±12.1cm vs 99.7±9.18cm, p=0.038) and neck circumference (33.6±3.03cm vs 35.1±2.27cm, p=0.042) were significantly higher in mothers that delivered LGA neonates. Mass spectrometry identified 2 significantly upregulated proteins, involved in antigen binding, in mothers that delivered LGA neonates. Furthermore, 4 proteins were significantly downregulated. Pregnancy-associated plasma protein A (PAPP-A) and vitamin K-dependent protein C were 0.52x and 0.59x lower respectively in women who delivered LGA neonates (p<0.005).

Combining protein biomarkers with anthropometric measures of obesity in trimester 1 may help to identify women at risk of delivering LGA neonates earlier than GDM diagnosis. Future work should validate these findings with laboratory-based tests to establish predictive thresholds.