Intermediate hyperglycemia in early pregnancy: A South Asian perspective

Table 1 Commonly used oral glucose tolerance test criteria for gestational diabetes diagnosis among South Asian women

Criteria	Glucose load	Plasma glucose threshold values				Number of abnormal values required for diagnosis	Remarks
		FPG mmol/l	1 h PG mmol/L	2 h PG mmol/L	3 h PG mmol/L
IADPSG, WHO 2013, ADA proposed “One step” procedure	75 g	≥ 5.1	≥ 10.0	≥ 8.5	-	1	Universal screening
DIPSI	75 g	-	-	≥ 7.8	-	1	Universal screening. OGTT in non-fasting state
ACOG and ADA proposed “Two step” procedures
Carpenter and coustan criteria	100 g	≥ 5.3	≥ 10.0	≥ 8.6	≥ 7.8	2	Universal screening, prior 50 g GCT positivity required (1-h PG ≥ 7.2 or 2-h PG ≥ 7.8 mmol/L)
NDDG criteria	100 g	≥ 5.8	≥ 10.5	≥ 9.0	≥ 8.0	2
						ACOG (2018) acknowledges higher risk for those with one abnormal value	ACOG (2018) permits institutions and individuals to use one step IADPSG procedure as well
NICE	75 g	≥ 5.6	-	≥ 7.8	-	≥ 1	Selective testing for high risk population1

¹High risk population = women having Body Mass Index > 30 kg/m², previous macrosomia (≥ 4500 g, previous GDM, family history of diabetes, ethnic origin with high prevalence of diabetes (South Asian, Black Caribbean, and Middle Eastern).

IADPSG: International Association of the Diabetes and Pregnancy Study Groups; WHO: World Health Organization; ADA: American Diabetes Association; DIPSI: Diabetes in Pregnancy Study group of India; ACOG: American College of Obstetricians and Gynaecologists; NICE: National Institute for Health and Care Excellence; OGTT: Oral glucose tolerance test; OCT: Oral glucose challenge test; NDDG: National Diabetes Data Group; FPG: Fasting plasma glucose; PG: Post load plasma glucose.

Table 2 Recommendations of various organizations for “intermediate hyperglycemia” screening before 24 gestational weeks

Organization	Timing	Target population	Test	Threshold PG values in mmol/L	Position of the association in 2022
International Association of the Diabetes and Pregnancy Study Group (IADPSG): 2010	First antenatal visit	Universal or only high-risk women	Fasting plasma glucose	5.1-6.9; if < 5.1, OGTT after 24 GW	2016: Withdrew the recommendation for FPG testing before 24 GW
World Health Organization: 2013	Any time before 24 GW	Not defined	75 g OGTT	FPG 5.1-6.9; 1-h PG ≥ 10; 2-h PG 8.5-11.0	No change from 2013 recommendation
American Diabetes Association (ADA): 2010	During first antenatal visit, suggest risk stratification	Those women with marked obesity, personal history of GDM, glycosuria, or a strong family history of diabetes, testing as soon as possible	One step test: 75 g 2-h OGTT, or two step test: 50 g OCT + 100 g 3-h OGTT	One step: FPG ≥ 5.2, 1-h ≥ 10, 2-h ≥ 8.6 (one abnormal value); two step: FPG ≥ 5.2, 1-h ≥ 10.0, 2-h ≥ 8.6, 3-h 7.8 (require two abnormal values)	2015: Test for undiagnosed diabetes at the first prenatal visit for those with risk factors, using standard diagnostic criteria; 2021: Test for undiagnosed pre-diabetes and diabetes at the first prenatal visit in those with risk factors using standard diagnostic criteria; 2022: Before 15 GW, test women with risk factors or consider testing all women for undiagnosed DM
2011-2014: Accepted IADPSG criteria for GDM diagnosis at 24-28 GW	No guideline for screening before 24 GW	Not specified	Nil		Screen women at risk for adverse events by FPG (6.1 mmol/L), HbA1c (4.1 mmol/mol)
American College of Obstetricians and Gynaecologists (ACOG): 2018	First antenatal visit, selective for women at risk for undiagnosed diabetes and GDM	Selective for women at risk for undiagnosed type 2 diabetes or GDM	Two step: 50 g OCT + 100 g 3-h OGTT1 or one step: 75 g OGTT in select situations	FPG > 5.3, > 5.8; 1-h PG ≥ 10, ≥ 10.6; 2-h PG ≥ 8.6, ≥ 9.2; 3-PG ≥ 7.8, ≥ 8.0 (NDDG or C&C criteria); one step same as IADPSG recommendations for DM, no specific recommendation for intermediate hyperglycemia	No Changes in criteria after 2018
Diabetes In Pregnancy Study group of India (DIPSI)	Yes	Universal	Non fasting 75 g OGTT	2 h PG ≥ 7.8	No further modifications
National Institute for Health and Care Excellence (NICE): 2015 and 2021	Yes	Selective for women with history of previous GDM at first antenatal visit; other risk factors, no testing before 24 GW	Blood self-monitoring of glucose or 75 g OGTT	FPG ≥ 5.6; 2 h PG ≥ 7.8	No further modification

¹American College of Obstetricians and Gynecologists approves both Carpenter and Coustan criteria and National Diabetes Data Group and PG threshold values of both criteria are shown.

3-PG: 3 h post glucose load plasma glucose values; GW: Gestational week; OGTT: Oral glucose tolerance test; PG: Plasma glucose; FPG: Fasting plasma glucose; DM: Type 2 diabetes; GDM: Gestational diabetes; OCT: Oral glucose challenge.

Table 3 Early Gestational diabetes among South Asian women: Oral glucose tolerance test based studies

Ref.	Region study location	No. of women	Diagnostic criteria and study design	GDM women-n (prevalence %), GW, no of GDM women (% of total GDM women)
Sharma et al[36], 2013	Jammu, India hospital	500	WHO 1999; preceded by 75 g non fasting OCT if 2-h PG ≥ 7.8 mmol/L, 75 g OGTT; at first prenatal visit	GDM: n = 55 (10%); 16-20 wk, 10 (18.1%); 21-24 wk, 20 (36.3%); 25-28 wk, 10 (18.1%); 29-32 wk, 15 (27.2%)
Seshiah et al[31], 2008	Chennai, Indian community	12056	WHO 1999; test at first prenatal visit; repeat at 24 GW and 32 GW	GDM: n = 1679 (13.9%); < 16 wk, 208 (12.4%); 17-23 wk, 280 (23.0%); ≥ 24 wk, 891.0%-64.6%
Dahiya et al[34], 2014	Rohtak, India hospital	500	DIPSI; test < 16 GW, if negative repeat at 24-28 GW	GDM: n = 35 (7%); < 16 wk, 4 (11.4%); second trimester-34 (88.6%)
Veeraswamy et al[37], 2016	Pan India study; peripheral clinic	9282	DIPSI; OGTT at first prenatal visit	GDM: n = 740 (8%); 1st trimester, 233 (31.5%); 2nd trimester, 320 (43.2%); 3rd trimester, 187(25.3%)
Neelakandan et al[30], 2014	Tirucharapalli, India hospital	1106	IADPSG; if preceding by 50 g OCT 1-h PG ≥ 7.2 mmol/L; first prenatal visit	GDM: n = 258 (23.3%); ≤ 12 wk, 36 (13.9%); 13-18 wk, 43 (16.7%); 19-28 wk, 114 (44.1%); ≥ 28 wk, 65 (25.2%)
Bhatt et al[38], 2015	Pune, India community	989	DIPSI with Capillary Glucose; OGTT any trimesters	GDM: n = 88 (8.9%); < 24 wk, 42 (47.9%); ≥ 24 wk, 46 (52.1%)
Anjalakshi et al[33], 2009	Chennai, India hospital	800	WHO 1999-M; OGTT between 16-32 GW	GDM: n = 87 (10.89%); 16-20 wk, 7 (8%); 21-24 wk, 17 (19.5%); 25-28 wk, 49 (56.3%); 29-32 wk, 14 (16.1%)
Seshiah et al[32], 2007	Chennai, India community	4151	WHO 1999-M; any trimester	GDM: n = 741 (17.9%); < 16 wk, 121 (16.3%); 17-23 wk, 166 (22.4%); ≥ 24 wk, 454 (61.27%)
Grewal et al[32], 2007	Delhi, India hospital	298	Carpenter and Coustan criteria; OGTT before 12 GW; women with DIP, IFG, and IGT excluded	GDM: n = 40 (13.42%); < 12 wk, 24 (60%); 24-28 wk, 16 (40%)
Bahl et al[40], 2022	Delhli, India community	2244	DIPSI; OGTT at first prenatal visit, repeat 24-28 wk, 34-36 wk	GDM: n = 430 (19.16%); 1st trimester, 112 (26.1%); 2nd and 3rd trimester, 318 (74%)
Punnose et al[39], 2023	Delhi, India hospital based	2638	IADPSG; first trimester HbA1c, if < 48 mmol/L, OGTT at any trimester; if OGTT negative before 24 GW repeat after 24 GW, DIP excluded	GDM: n = 722 (27.37%); < 14 wk, 125 (17.3%); 14-23 wk, 130 (18%); ≥ 24 wk, 467 (64.68%)
Sudasinghe et al[43], 2016	SriLanka community	1533	WHO-1999; initial screening in first trimester by 2-h post prandial PG ≥ 6.7-11.1 mmol/L OGTT at 16 GW, if negative repeat after 24 GW, DIP excluded	GDM: n = 169 (11.02%); < 16 wk, 19 (12.67%)
Jayawardane et al[41], 2018	Sri Lanka hospital	Not given	WHO 1999 (2011-14) and DIPSI (2014-15), OGTT in any trimesters, DIP excluded	GDM: n = 435 (total number not available); 12-23 wk, 104 (23.9%); ≥ 24 wk, 331 (76.09%)
Mazumder et al[42], 2022	Bangladesh community	265	IADPSG; OGTT in any trimester	GDM: n = 92 (34.71%); 1st trimester, 33 (35.87%); 2nd trimester, 36 (39.13%); 3rd trimester, 23 (25%)

Values in bold indicate percentage of women diagnosed before 24 gestational weeks. GW: Gestational weeks; WHO: World Health Association; OCT: Oral glucose challenge; OGTT: Oral glucose tolerance test; DIPSI: Diabetes In Pregnancy Study group of India; IADPSG: International Association of the Diabetes and Pregnancy Study Group; DIP: Diabetes in pregnancy; IGT: Impaired glucose tolerance; IFG: Impaired glucose tolerance; 1-h PG: Post Glucose load 1 h plasma glucose.