GDM screening & intervention @ 11–13⁺⁶ instead of 24–28 weeksʼ gestation: time for a change in paradigm?

In June 2025 an amendment of the first trimester diagnosis and therapy @ 11–13⁺⁶ weeks gestation guideline [1] was accepted by the AWMF.

This had become necessary because a trilogy on gestational diabetes mellitus (GDM), published in “Lancet” in June 2024, had made a fundamental paradigm shift towards the first trimester (LoE 1) [2] [3] [4]. In this issue, you will find a short version of the amendment of chapter 11 of the guideline. A summary of the guideline had been previously published in 2 parts in “Ultraschall in der Medizin” [5] [6].

GDM is a heterogeneous condition that has an incidence of 14 % and up to 40 % of women [2]. This makes it the most common complication of pregnancy. Thus, GDM is an important topic in fetal medicine.

The previous philosophy assumed that an elevated glucose level in pregnancy is only relevant from the 24–28 weeks of pregnancy (LoE 1a) [2] [7].

The new paradigm is that gestational diabetes is a heterogenous condition with foundations for it commencing already before pregnancy. GDM often occurs in early pregnancy and benefits from targeted early treatment. Furthermore, the consequences of gestational diabetes should be considered to follow a life course trajectory [2].

The main adverse outcomes of GDM are macrosomia, neonatal respiratory distress, fetal and maternal injury at birth such as shoulder dystocia, and life-long increased risks for glucose intolerance, obesity, as well as metabolic syndrome and hypertension [2].

The prerequisite to make GDM screening a fourth and major component of first trimester screening @ 11–13⁺⁶ weeks of gestation is that (I) screening is available which reliably identifies a high risk group with a low false-positive rate, (II) early intervention is feasible and effective and (III) this concept can be realized within the existing resources.

Most of all, however, high quality clinical studies are critically important, which have provided sound robust evidence for the fact that early screening and intervention practically improve outcomes and have a benefit for mothers and their babies [8].

The TOBOGM Trial [9] [10] [11] indicates that women with high glucose levels and early onset GDM, already occurring in the first trimester, may benefit the most from an early screening and intervention. Therefore, the current screening strategy recommends the identification of GDM risk factors to every pregnant woman as an integral part of the first trimester screening @ 11–13⁺⁶ weeks. If one of them is found, a 75 g oGTT is done. The recommended cut-offs [12] are slightly higher than those of the WHO [13], as TOBOGM suggested overtreatment may result in Fetal Growth Restriction (FGR), when WHO cut-offs are used. Therefore higher cut-offs were chosen @ 11–13⁺⁶ weeks of gestation than for 24–28 weeks of gestation – in order to identify a high risk group [12]. If screening is found to be positive, lifestyle intervention, dietary advice, glucose self-monitoring and – in some cases – insulin therapy are introduced. If self-monitoring shows normal glucose levels, a repeat oGTT @ 24–28 weeks can be omitted. If the pregnant woman does not tolerate an oGTT, fasting glucose and HbA1c are measured as surrogate markers. If oGTT is screening-negative in the first trimester, it has to be repeated @ 24–28 weeks of pregnancy.

The current evidence shows that an early screening and intervention halves macrosomia and respiratory distress at birth for these high risk groups.

Early screening and intervention for GDM should thus be an integral part of first trimester screening @ 11–13⁺⁶ weeks of pregnancy in German-speaking countries.

Univ.-Prof. Dr. Constantin von Kaisenberg

Conflict of Interest

The authors declare that they have no conflict of interest.

• References

• 1 Deutsche Gesellschaft für Ultraschall in der Medizin e.V. (DEGUM), Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e.V. (DGGG). S2e-Leitlinie Ersttrimester Diagnostik und Therapie @ 11-13+6 Schwangerschaftswochen. Version 1.3 (2025). AWMF-Registernummer: 085-002.
• 2 Hivert MF, Backman H, Benhalima K. et al. Pathophysiology from preconception, during pregnancy, and beyond. Lancet 2024; 404: 158-174
• 3 Sweeting A, Hannah W, Backman H. et al. Epidemiology and management of gestational diabetes. The Lancet 2024; 404: 175-192
• 4 Simmons D, Gupta Y, Hernandez TL. et al. Call to action for a life course approach. Lancet 2024; 404: 193-214
• 5 von Kaisenberg C, Kozlowski P, Kagan KO. et al. Ersttrimester Diagnostik und Therapie @ 11–13+6 Schwangerschaftswochen – Teil 1. Ultraschall in Med 2025; 46: 36-48
• 6 von Kaisenberg C, Kozlowski P, Kagan KO. et al. Ersttrimester Diagnostik und Therapie @ 11–13+6 Schwangerschaftswochen – Teil 2. Ultraschall in Med 2025; 46: 145-161
• 7 Crowther CA, Hiller JE, Moss JR. et al. Effect of Treatment of Gestational Diabetes Mellitus on Pregnancy Outcomes. N Engl J Med 2005; 352 (24) 2477-2486
• 8 Bhattacharya S, Nagendra L, Dutta D. et al. Treatment Versus Observation in Early Gestational Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Controlled Trials. J Clin Endocrinol Metab 2024; dgae878
• 9 Simmons D, Immanuel J, Hague WM. et al. Treatment of Gestational Diabetes Mellitus Diagnosed Early in Pregnancy. N Engl J Med 2023; 388 (23) 2132-2144
• 10 Simmons D, Immanuel J, Hague WM. et al. Effect of treatment for early gestational diabetes mellitus on neonatal respiratory distress: A secondary analysis of the TOBOGM study. BJOG: Int J Obstet Gynaecol 2024;
• 11 Simmons D, Nema J, Parton C. et al. The treatment of booking gestational diabetes mellitus (TOBOGM) pilot randomised controlled trial. BMC Pregnancy Childbirth 2018; 18 (01) 151
• 12 Benhalima K, Geerts I, Calewaert P. et al. The 2024 Flemish consensus on screening for gestational diabetes mellitus early and later in pregnancy. Acta Clin Belg 2024; 79 (03) 217-224
• 13 Metzger BE, Gabbe SG, Persson B. et al. International Association of Diabetes and Pregnancy Study Groups Recommendations on the Diagnosis and Classification of Hyperglycemia in Pregnancy. Diabetes Care 2010; 33 (03) 676-682

Publication History

Article published online:
09 September 2025