What are the recommended screening protocols for gestational diabetes in pregnant women?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Recommended screening protocols for gestational diabetes mellitus (GDM) in pregnant women:

  • At the booking appointment, assess risk factors for GDM including BMI above 30 kg/m2, previous macrosomic baby weighing 4.5 kg or more, previous gestational diabetes, family history of diabetes (first-degree relative), and ethnicity with a high prevalence of diabetes. Women with any of these risk factors should be offered testing for GDM .
  • Do not use fasting plasma glucose, random blood glucose, HbA1c, glucose challenge test, or urinalysis for glucose to assess risk of developing GDM .
  • For women with previous gestational diabetes, offer early self-monitoring of blood glucose or a 75-g 2-hour oral glucose tolerance test (OGTT) as soon as possible after booking (first or second trimester), and a further 75-g 2-hour OGTT at 24 to 28 weeks if the first OGTT is normal .
  • For women with other risk factors, offer a 75-g 2-hour OGTT at 24 to 28 weeks gestation .
  • Consider further testing to exclude GDM in women with glycosuria of 2+ or above on one occasion or glycosuria of 1+ or above on two or more occasions during routine antenatal care .
  • Diagnose GDM if fasting plasma glucose is 5.6 mmol/l or above, or 2-hour plasma glucose is 7.8 mmol/l or above following the OGTT .

Educational content only. Always verify information and use clinical judgement.