Table 1.

Comparison of Liverpool and Waikato Diagnostic and Treatment Approaches for Gestational Diabetes Diagnosis.

	Waikato NZSSD 1995 [10]	Waikato NZMOH 2014	Liverpool ADIPS 1991 [7,8]	Liverpool IADPSG [9,13]
SCREENING APPROACH
	Universal GCT	Booking HbA1c (<20 weeks) If ≤40 mmol/mol (5.8%), do GCT if 41–49 mmol/mol (5.9–6.6%), do OGTT ≥50 mmol/mol (6.7%), referral to diabetes in pregnancy service	Risk-based screening: Low risk groups: GCT at 26–28 weeks, if ≥7.8 mmol/L then OGTT High risk groups *: OGTT at time of antenatal booking, if normal repeat OGTT at 26–28 weeks	Universal OGTT at 24–28 weeks Early OGTT performed at any time for those with 1 high risk factors or 2 moderate risk factors *
RISK FACTORS FOR SCREENING
			Risk factors include glycosuria, age > 30 years, obesity, family history of diabetes, past history of GDM or glucose intolerance, previous adverse pregnancy outcome, belonging to an ethnic group with a high risk for GDM (e.g., Indigenous, Polynesian, Middle Eastern and Asian).	High risk factors include: previous GDM, elevated BGL, age ≥ 40 years, 1st degree family history (or sister with GDM), BMI > 35 kg/m2, previous macrosomia (>4500 g or >90th centile), polycystic ovarian syndrome, on corticosteroids or antipsychotics. Moderate risk factors include: Asian, Indian subcontinent, Aboriginal, Torres Strait Islander, Pacific Islander, Maori, Middle Eastern, or non-white African ethnicity. BMI 25–35 kg/m2.
ORAL GLUCOSE TOLERANCE TEST DIAGNOSTIC CUT OFFS
1-h 50 g GCT cut offs:	-≥11.1 mmol/- referral to diabetes in pregnancy service -7.8–11.0 mmol/L, proceed to OGTT	If HbA1c at booking is ≤40 mmol/mol (5.8%) If ≥7.8 mmol/L, proceed to OGTT
OGTT fasting level (mmol/L)	≥5.5	≥5.5	≥5.5	≥5.1
OGTT 1-h level				≥10.0
-OGTT 2-h level (mmol/L)	≥9.0	≥9.0	≥8.0	≥8.5
TREATMENT TARGETS
-Fasting BGL (mmol/L)	≤5.5	≤5.0	≤5.5	≤5.3
-1-h BGL (mmol/L)		≤7.4	N/A	≤7.4
-2-h BGL (mmol/L)	≤6.5	≤6.7	≤7.0	≤7.0

BGL = blood glucose level, GCT = glucose challenge test, ADIPS = Australian Diabetes in Pregnancy Society, IADPSG = International Association of Diabetes and Pregnancy Study Groups, NZMOH = New Zealand Ministry of Health, NZSSD = New Zealand Society for Study of Diabetes, OGTT: oral glucose tolerance test. * Risk factors described in section “Risk Factors for Screening”