Is it HAPO/IADPSG and NICE/ National Consensus Document criteria for diagnosis of GDM best suit for Sri Lanka; Outcomebased comparative study

Objective: Our aim in this study is to compare pregnancy and fetal outcomes following the diagnosis of gestational diabetes according to HAPO/IADPSG, NICE criteria or when using both criteria.

Methods: Diagnosis of GDM was made using the lowest recommended cut off values of HAPO/IADPSG criteria and NICE criteria. NICE diabetes in pregnancy guidelines were used in management once GDM was diagnosed. The outcomes of the three groups were compared, Group A: the patients diagnosed using any criteria, Group B: only from HAPO/IADPSG criteria (patients fasting value within 92-100 mg/dL and other values with in the normal). Group C: only from NICE criteria (patients with 2^nd hour value within 140-153 mg/dL but the rest were normal)

Results: Out of all women with GDM 70% were in group A, 25% in group B, and only 4% in group C. 62% of women needed metformin or insulin apart from Medical nutrition therapy in Group A, and 50% in group B and only 17% in group C. Average period of gestation at the delivery in Group A was 37 weeks and 3 days , and it is 37+5 for group B and 38+4 for group C. Induction rate in Group A was 56%, 14% in Group B and 4% in Group C.LSCS rate was 48% in Group A, 41% in group B and 36% in group C. 7% of babies were macrosomic in Group A, 2% and 1% respectively in groups B and C. Special Care Baby Unit (SCBU) admission rates were 11% in group A and 1% in group B. The average birth weights of Group A were 2.93kg, Group B 2.900kg and group C 2.818kg.

Conclusion: HAPO/IADPSG criteria diagnosed more women with gestational diabetes than NICE criteria. Only 4% of mothers will be missed if HAPO/IADPSG criteria is used. Pregnancy outcomes of the Group B is similar to that of Group A and 50% of women needing further intervention apart from MNT could have prevented adverse pregnancy outcome in a significant number of patients compared to the few number of patients in group C. It was observed that IADPSG criteria provide better diagnostic cut-off values for our population compared to NICE. Limited number of patients especially in group C is a limitation of this study to evaluate further since this is an on-going observational study and will be able to provide more information in the future.