Poster Presentation International Association of the Diabetes and Pregnancy Study Groups 2022 - Hosted by ADIPS

Employing fasting plasma glucose to safely limit the use of oral glucose tolerance tests in pregnancy: a pooled analysis of four Norwegian prospective studies with universal screening for gestational diabetes (#123)

Anam ASR Rai 1 2 , Line LS Sletner 3 4 , Anne Karen AKJ Jenum 5 , Nina Cecilie NCØ Øverby 6 , Signe SNS Stafne 7 8 , Elisabeth EQ Qvigstad 9 10 , Are Hugo AHP Pripp 11 , Linda Reme LRS Sagedal 12 13
  1. Department of Nutrition and Public Health, Faculty of Health and Sport Sciences, University of Agder, Kristiansand, Norge
  2. Department of Research, Sørlandet Hospital, Kristiansand, Norge
  3. Department of Pediatric and Adolescents Medicine, Akershus University Hospital, Akershus, Norway
  4. Institute of Clinical Medicine,, University of Oslo, Oslo, Norway
  5. Department of General Medicine, General Practice Research Unit (AFE), Institute of Health and Society, University of Oslo, Oslo, Norway
  6. Department of Nutrition and Public Health, Faculty of Health and Sport Sciences, University of Agder, Kristiansand, Norge
  7. Department of Clinical Services, , St. Olavs Hospital Trondheim University Hospital, , Trondheim, , Norway
  8. Department of Public Health and Nursing, , Norwegian University of Science and Technology (NTNU), , Trondheim, Norway
  9. Department of Pediatric and Adolescents Medicine, Akershus University Hospital, Oslo, Norway
  10. Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, oslo , Norway
  11. Oslo Centre of Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway
  12. Department of Research, Sørlandet Hospital, Kristiansand, Norge
  13. Department of Obstetrics and Gynaecology, Sørlandet Hospital, Kristiansand, Norge

Objective

To investigate the use of fasting plasma glucose (FPG) to identify women at low risk for gestational diabetes mellitus (GDM) and GDM-related adverse outcomes, limiting the need for an oral glucose tolerance test (OGTT).

Design and setting

Pooled data from four Norwegian pregnancy cohorts, collected between 2002 and 2013.

Population

2960 pregnant women universally screened with mid-pregnancy 75g OGTT measuring FPG and 2-hour glucose.

Methods

For a range of FPG thresholds, we calculated sensitivity to predict elevated 2-hour glucose, number of OGTTs needed and percentage of GDM cases missed, applying modified 2013World Health Organization (2013WHO) and 2017Norwegian criteria. We analyzed pregnancy outcomes such as large-for-gestational-age newborns, cesarean section and operative delivery for women above and below our selected threshold.

Results

The prevalence of GDM was 16.6% with the 2013WHO criteria and 10.1% with the 2017Norwegian criteria. A FPG threshold of 4.7mmol/L had a sensitivity of 76% (2013WHO) and 80% (2017Norwegian) for detecting elevated 2-hour glucose, with few missed GDM cases (7% for 2013WHO, 8% for 2017Norwegian). Excluding women with FPG <4.7mmol/l and those with GDM based on FPG, only 24% (2013WHO) and 29% (2017Norwegian) would require OGTT. Women with FPG <4.7mmol/l, including missed GDM cases, had low risk of large-for-gestational-age newborns, cesarean section and operative delivery.

Conclusion

A FPG threshold of 4.7mmol/l as a first step when screening for GDM could potentially eliminate the need for OGTT in 70-77% of pregnancies. Women with FPG below this threshold appear to carry low risk of GDM-associated adverse pregnancy outcomes.