Table 4.
Sensitivity and specificity at each index test threshold. Full data extracted from each paper provided in supplementary appendix.* ADIPS / RANZCOG guidelines state that pregnant people with FPG ≥4.7 mmol/L are referred for further OGTT if between 4.7–5.0 mmol/L and diagnosed as GDM if ≥5.1 mmol/L. All pregnant people with an FPG <4.7 mmol/L would therefore be classified incorrectly as non-GDM. ⁎⁎Value provided is the sensitivity for the combination of thresholds; individual proportions were unavailable. ⁎⁎⁎IADPSG data solely shown here due to complexity; NICE data can be found in supplementary appendix. &Data presented is for universal screening only; selective screening data found in supplementary appendix. #Specificity data unavailable for some papers.
| Study | Gold standard reference | Sample size (n with GDM) | Gestation at testing (weeks) | Index test | Index threshold | Sensitivity (%) | Specificity (%)# |
|---|---|---|---|---|---|---|---|
| Zhu | IADPSG | 237 | 1–26 | FPG | ≥4.7 mmol/L* | 75 | – |
| HbA1c | ≥5.9% (41 mmol/mol) | 2 | – | ||||
| Van Gemert | IADPSG | 1992 | 1–32 | FPG | ≥4.7 mmol/L* | 71 | – |
| McIntyre | IADPSG | 1014 | 24–32 | FPG | ≥4.7 mmol/L* | 75 | – |
| Diabetes Canada | 555 | HbA1c | ≥5.7% (39 mmol/mol) | 18 | – | ||
| Siru | IADPSG | 1790 | 24–28 | FPG | ≥4.7 mmol/L* | 54 | – |
| D'Emden | IADPSG | 3946 | 24–32 | FPG | ≥4.7 mmol/L* | 73 | – |
| Kasuga | IADPSG | 264 | 13–26 | FPG | ≥5.1 mmol/L | 34 | – |
| HbA1c | ≥5.7% (39 mmol/mol) | 13 | – | ||||
| RPG | ≥9.0 mmol/L | 0 | – | ||||
| Nachtergaele [30] | IADPSG | 467 | 22–30 | FPG | ≥5.1 mmol/L& | 54 | – |
| HbA1c | ≥5.7%& (39 mmol/mol) | 15 | – | ||||
| Nachtergaele [31] | NICE | 312 | 22–30 | FPG | ≥5.6 mmol/L& | 33⁎⁎ | – |
| HbA1c | ≥5.7% (39 mmol/mol) | – | |||||
| Nachtergaele [29] | IADPSG | 481 | 22–30 | FPG | ≥4.7 mmol/L* | 69& | 100 |
| ≥5.1 mmol/L | 49& | 100 | |||||
| Ikomi | IADPSG | 694 | 24–28 | FPG | ≥5.1 mmol/L | 64 | 100 |
| NICE | 460 | ≥5.6 mmol/L | 36 | 100 | |||
| Issa | NICE | 152 | 28 | FPG | ≥5.6 mmol/L | 43 | – |
| ≥5.3 mmol/L | 50 | – | |||||
| HbA1c | ≥5.7% (39 mmol/mol) | 12 | – | ||||
| Meek | IADPSG⁎⁎⁎ | 776 | 24–32 | HbA1c | ≥5.7% (39 mmol/mol) | 30 | 97 |
| FPG | ≥5.6 mmol/L | 13 | 100 | ||||
| ≥5.3 mmol/L | 25 | 100 | |||||
| ≥5.1 mmol/L | 40 | 100 | |||||
| 30 | RPG | ≥9.0 mmol/L | 30 | 98 | |||
| Van-De-L'Isle | NICE | 86 | 28 | FPG | ≥5.3 mmol/L | 41⁎⁎ | – |
| HbA1c | ≥5.7% (39 mmol/mol) | – | |||||
| RPG | ≥9.0 mmol/L | – |