Table 1 Characteristics of the 40 included studies and their respective STROBE scores
Author year [Ref] | Country | Screening procedure | Diagnostic criteria | 50 GCT cut-off mmol/L | Fasting cut-off mmol/L | 1 h cut-off mmol/L | 2 h cut-off mmol/L | 3 h cut-off mmol/L | 1 or 2-steps | Sample size | GDM cases | STROBE Score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Notelovitz 1969 [33] | South Africa | Fasting, 2 h OGTT (100 g) | Own criteria, modified O’Sullivan & Mahan |  | 6.4 |  | 8.3 |  | One step | 301 | 25 | 14 |
Jackson 1979 [34] | South Africa | Fasting, 1 h 2 h OGTT (50 g) | Own criteria, adapted O’Sullivan & Mahan |  | 5.5 | 10.0 | 6.7 |  | One step | 558 | 17 | 14 |
Abudu 1987 [35] | Nigeria | 50 g GCT, fasting, 1 h 2 h OGTT (50 g) | O’Sullivan & Mahan | 7.2 | 5.0 | 9.2 | 8.1 |  | Two steps | 336 | 5 | 14 |
Swai 1991 [36] | Tanzania | Fasting, 2 h OGTT (75 g) | WHO 1985 |  | 7.8 |  | 11.1 |  | One step | 189 | 0 | 14 |
Ranchod 1991 [37] | South Africa | 50 g GCT, fasting, 2 h OGTT (75 g) | WHO 1985 | 7.8 |  |  | 7.8 |  | Two steps | 1717 | 65 | 15 |
Seyoum 1999 [38] | Ethiopia | Fasting, 2 h OGTT (75 g) | WHO 1985 |  |  |  | 7.8 |  | One step | 890 | 33 | 17 |
Ozumba 2004 | Nigeria | Fasting, 2 h OGTT (75 g) | WHO 2006 |  | 7 |  | 11.1 |  | One step | 5025 | 15 | 14 |
Olarinoye 2004 [40] | Nigeria | 3 h OGTT (75 g) | WHO 1985 |  |  |  | 7.8 |  | One step | 138 | 16 | 17 |
Mamabolo 2007 [41] | South Africa | Fasting, 2 h OGTT (75 g) | WHO 2006 |  | 7.0 |  | 11.1 |  | One step | 262 | 4 | 18 |
Adegbola 2008 [42] | Nigeria | 50 g GCT, 1 h, 2 h, 3 h OGTT (100 g) | CC criteria | 7.2 | 5.3 | 10.0 | 8.6 | 7.8 | Two steps | 241 | 12 | 16 |
Kamanu 2009 [43] | Nigeria | 50 g GCT, 1 h 2 h OGTT (75 g) | modified CC | 7.8 |  | 10.0 | 8.6 |  | Two steps | 9040 | 140 | 18 |
Basu 2010 [44] | South Africa | Fasting or random blood | Institutional protocol | Â | 8.0 | Â | Â | Â | One step | 767 | 14 | 18 |
Kuti 2011 [45] | Nigeria | Fasting 2 h OGTT (75 g) | WHO 1999 |  | 7.0 |  | 7.8 |  | One step | 765 | 106 | 18 |
Tandu-Mba 2012 [46] | DR Congo | Fasting only | ADA 2003/4 | Â | 5.3 | Â | Â | Â | One step | 108 | 8 | 14 |
Jao 2013 [47] | Cameroon | Fasting only | ADA 2010 | Â | 5.3 | Â | Â | Â | One step | 316 | 20 | 16 |
Anzaku 2013 [48] | Nigeria | 50 g GCT, 2 h OGTT (75 g) | WHO 1985 | 7.8 |  |  | 7.8 |  | Two steps | 253 | 21 | 18 |
Mwanri 2013 [49] | Tanzania | Fasting, 2 h OGTT (75 g) | IADPSG |  | 6.1 |  | 7.8 |  | One step | 910 | 119 | 20 |
Fawole 2013 [50] | Nigeria | Fasting, 2 h OGTT (75 g) | WHO 1999 |  | 7.0 |  | 7.8 |  | One step | 530 | 9 | 18 |
Minsart 2014 [51] | Djibouti | Fasting, 1 h 2 h OGTT (75 g) | IADPSG |  | 5.1 | 10.0 | 8.5 |  | One step | 231 | 106 | 17 |
Olagbuji 2015 [52] | Nigeria | Fasting, 1 h 2 h OGTT (75 g) | IADPSG |  | 5.1 | 10.0 | 8.5 |  | One step | 1059 | 91 | 19 |
Oppong 2015 [53] | Ghana | Fasting, 1 h 2 h OGTT (75 g) | WHO 2013 |  | 5.1 | 10.0 | 8.5 |  | One step | 399 | 37 | 19 |
Olagbuji 2017 [54] | Nigeria | Fasting, 1 h 2 h OGTT (75 g) | IADPSG |  | 5.1 | 10.0 | 8.5 |  | Two steps | 280 | 44 | 17 |
Mapira 2017 [55] | Rwanda | Fasting only | ADA 2011 | Â | 7.0 | Â | Â | Â | One step | 288 | 24 | 18 |
Pastakia 2017 [56] | Kenya | Fasting, 1 h 2 h OGTT (50/75 g) | IADPSG |  | 5.1 | 10.0 | 8.5 |  | One step | 616 | 18 | 16 |
Nakabuye 2017 [57] | Uganda | Fasting, 2 h OGTT (75 g) | WHO 2013 |  | 5.1 |  | 8.5 |  | One step | 251 | 76 | 17 |
Oriji 2017 [58] | Nigeria | Fasting, 1 h 2 h OGTT (75 g) | WHO 2013 |  | 5.1 | 10.0 | 8.5 |  | One step | 235 | 35 | 18 |
Adam 2018 [59] | South Africa | Fasting, 1 h 2 h OGTT, 75 g | WHO 2013 |  | 5.1 | 10.0 | 8.5 |  | One step | 529 | 141 | 15 |
Njete 2018 [21] | Tanzania | Fasting, 1 h 2 h OGTT, 75 g | WHO 2013 |  | 5.1 | 10.0 | 8.5 |  | One step | 333 | 65 | 20 |
Nhidza 2018 [60] | Zimbabwe | Fasting, 2 h OGTT, 75 g | WHO 2006 |  | 7.0 |  | 11.1 |  | One step | 150 | 10 | 14 |
Macaulay 2018a [24] | South Africa | Fasting, 1 h 2 h OGTT, 75 g | IADPSG |  | 5.1 | 10.0 | 8.5 |  | One step | 1906 | 179 | 21 |
Macaulay 2018b [61] | South Africa | Fasting, 1 h 2 h OGTT, 75 g | WHO 2013 |  | 5.1 | 10.0 | 8.5 |  | One step | 741 | 83 | 21 |
Egbe 2018 [23] | Cameroon | Fasting, 1 h 2 h OGTT, 75 g | IADPSG |  | 5.1 | 10.0 | 8.5 |  | One step | 200 | 41 | 18 |
Feleke 2017 [22] | Ethiopia | NR | NR | NR | NR | NR | NR | NR | NR | 2257 | 567 | 17 |
| Â | Â | Â | Â | Â | Â | Â | Â | Total | Â | 31,821 | 2146 | Â |