Table 2. Characteristics of studies included in the systematic review.

First author	Year	Country	GDM diagnosis criterion	Total women	No. with GDM	% with GDM	Risk factor screening strategy
Avalos[33]	2013	Ireland	IADPSG	5500	521a	9	Irish, NICE, ADA guideline recommendations
					491b	9
					585c	11
Caliskan[39]	2004	Turkey	NDDG	422	14	3	Number of risk factors
Cosson[34]	2013	France	WHO	18755	2710	14	French guideline recommendations
Cypryk[40]	2008	Poland	WHO	2180	510	23	Number of risk factors
Danilenko-Dixon[35]	1999	USA	NDDG	18504	564	3	ADA guideline recommendations
Erum[51]	2015	Turkey	ADA	815	39	5	‘At least one risk factor’
Gabbay-Benviz[58]	2015	USA	C&C	924	63	7	Risk score
Jensen[61]	2003	Denmark	DPSG	2992d	83	3	Number of risk factors
Jiminez-moleon[36]	2002	Spain	NDDG	1436	58c	4	ADA and ACOG guideline recommendations
				2174	63e	3
Kirke[59]	2014	Australia	WHO	1636	73	4	Risk score
Marquette[42]	1985	USA	C&C	434	12	3	Number of risk factors
Moses[47]	1998	Australia	ADIPS	2907	183	6	Age, BMI ethnicity
Nanda[52]	2011	UK	WHO	11464	297	3	Risk model
Naylor[53]	1997	US	NDDG or C&C	1571	69	4	Risk score
Nielsen[43]	2016	India	WHO	3946	659	17	Number of risk factors (1, 2 or 3)
Ostlund[28]	2003	Sweden	WHO	3616	61	5	"Traditional risk factors"
Phaloprakam[54]	2009	Thailand	C&C	469	127	27	Risk score
Pintaudi[48]	2014	Italy	IADPSG	1015	113	11	"Standard risk factors"
Sacks[44]	1987	USA	ADA	4116	138	3	Number of risk factors
Savona-Ventura[49]	2013	Mediterranean	ADA	1368	119	9	Based on age, obesity or diastolic BP
Shamsuddin[45]	2001	Malaysia	OGTT levels reported	768	191	25	Number of risk factors
Shirazian[55]	2009	Iran	ADA	924	68	7	Risk score
Sunsaneevithayakul[46]	2003	Thailand	Not reported	9325	235	2	Number of risk factors
Syngelaki[60]	2015	UK	WHO	75161	1827	20	Risk model
Teh[37]	2011	Australia	ADIPS	2426	250	10	NICE, ADA and ADIPS guideline recommendations
van Leeuwen[57] (A)	2010	Netherlands	OGTT/GCT levels reported	995	24	2	Risk model
van Leeuwen[56] (B)	2009	Netherlands	WHO	1266	47	4	Risk score
Williams[50]	1999	USA	NDDG	25118	210f	1	Based on age, BMI ethnicity, family history
Yang[38]	2002	China	WHO	9471	171	2	ADA guideline

^aIrish guideline

^bNICE guideline

^cADA recommendations

^dJensen (2003), 5235 women were included in the study, 2992 had an OGTT performed

^eACOG recommendations

^fWilliams (1999), number of women with GDM varied by the recorded risk factor (i.e. not all women had all risk factors recorded)

ACOG = American College of Obstetricians and Gynecologists

ADA = American Diabetes Association

ADIPS = Australasian Diabetes In Pregnancy Society

C&C = Carpenter and Coustan

NDDA = National Diabetes Data Group

NICE = National Institute for Health and Care Excellence

IADPSG = International Association of Diabetes in Pregnancy Study Groups

WHO = World Health Organization