Table 2 Mean prevalence of GDM by several moderator variables for studies using two-step screening strategy

Diagnostic criteria used

1 Carpenter-Coustan

8

266,080

8.1%

6.3–10.4

24.4 [3]*

889.03 [7]^*

99.2

2 NDDG

11

402,180

3.6%

2.9–4.5

1170.28 [10]*

99.1

3 O’Sullivan & Mahan

2

1,806

7.6%

4.4–12.7

2.62 [1]

61.8

4 Canada (1998)

5

844,773

5.2%

3.7–7.1

4330.44 [4]^*

99.9

Country

Canada

8

1,054,163

4.7%

3.4–6.3

0.86 [1]

6749.39 [7]^*

99.9

USA

18

461,126

5.5%

4.5–6.7

3070.65 [17]^*

99.4

Start of data collection period

1980–1990

5

45,401

4.8%

3.4–6.6

16.62 [3]^*

96.25 [4]^*

95.8

1991–2001

12

1,098,324

4.0%

3.3-5.0

4,047.43 [11]^*

99.7

2002–2012

7

351,5019

7.6%

5.8–9.9

2016.47 [6]^*

99.7

2013–2023

2

20,635

8.0%

4.9–12.9

5.11 [1]^*

80.4

End of data collection period

1980–1990

3

14,474

4.1%

2.6–6.3

5.58 [3]

15.74 [2]^*

87.3

1991–2001

6

248,912

4.1%

3.1–5.6

450.06 [5]^*

98.9

2002–2012

13

1,173,337

5.8%

4.7-7.0

5975.99 [12]^*

99.8

2013–2023

4

78,656

6.3%

4.4–8.9

1249.69 [3]^*

99.8

Mean age

< 30 years

7

717,177

5.2%

3.9–7.1

4.03 [2]

1884.32 [6]^*

99.7

> 30 years

6

347,307

6.8%

5.0-9.3

2259.15 [5]^*

99.8

Nulliparous

> 50%

4

311,062

6.1%

4.1–9.2

3.73 [2]

961.48 [3]^*

99.7

< 50%

6

398,690

6.6%

4.7–9.1

3,938.94 [5]^*

99.9

Ethnic mix

> 70% First Nations

2

1,806

7.6%

4.2–13.3

2.31 [3]

2.62 [1]

61.8

> 70% Caucasian

2

42,004

5.2%

2.9–9.1

309.21 [1]

99.7

> 70% Hispanic/Latino

3

43,491

6.1%

3.8–9.6

258.87 [2]

99.2

Mixed or unknown

19

1,428,078

4.9%

4.1–5.9

9466.17 [18]

99.8

Routine dataset

No

15

156,668

6.1%

4.9–7.5

4.78 [1]*

2506.53 [14]^*

99.4

Yes

11

1,358,711

4.3%

43.4–5.4

7455.56 [10]^*

99.9

Whether women with pre-pregnancy diabetes included in denominator

Included

5

664,660

3.9%

2.7–5.4

4.72 [2]

537.15 [4]^*

99.3

Excluded

20

833,112

5.5%

4.7–6.5

6662.83 [19]^*

99.7

Whether women could be included more than once

Yes

12

1,135,186

4.2%

3.3–5.4

6.61 [2]*

7524.35 [11] ^*

99.9

No

13

362,586

6.2%

4.9–7.8

1967.39 [12] ^*

99.4