Trials comparing metformin to insulin
| First author | Year | Location | No | Diagnostic test and glucose thresholds used to diagnose GDM | Screening strategy* | Meta-analysis outcome |
| Ainuddin66 | 2014 | Pakistan | 150 | 75 g OGTT two or more; fasting 5.3, 1 hour 10.0, 2 hours 8.6 | 50 g OGCT ≥7.8 | PIH, pre-eclampsia, GA at delivery, induction, C-section, LGA, NICU admission, neonatal hypoglycaemia |
| Hague64 | 2003 | Australia | 30 | 75 g OGTT fasting >5.5 or 2 hours >8.0 | Risk factors | BW, pre-eclampsia, GA at birth, induction, C-section, macrosomia, hypoglycaemia |
| Hassan65 | 2012 | Pakistan | 150 | 75 g OGTT two or more levels fasting >5.3, 1 hour >10.0 or 2 hours >8.6 | 50 g OGCT >7.8 | Apgar 5 min, GA at birth, induction, C-section, BW, macrosomia, hypoglycaemia, NICU admission |
| Ijas63 | 2010 | Finland | 100 | 75 g OGTT fasting >5.3, 1 hour >11.0 or 2 hours >9.6 | Risk based | Apgar 5 min, BW, C-section, GA at birth, induction, instrumental birth, LGA, macrosomia, hypoglycaemia, NICU admission |
| Mesdaghinia62 | 2013 | Iran | 200 | 100 g OGTT two or more; fasting >5.3 or 1 hour >10.0 or 2 hours >8.6 or 3 hours >7.8 | 50 g OGCT – levels not reported | BW, macrosomia, LGA, hypoglycaemia, NICU admission, shoulder dystocia, 5 min Apgar <7, preterm birth |
| Moore61 | 2007 | USA | 63 | 100 g OGTT two or more; fasting >5.8 or 1 hour >10.5 or 2 hours >9.1 or 3 hours >8.0 | 50 g OGCT >7.8 | Apgar 5 min, BW, macrosomia, hypoglycaemia, NICU admission |
| Niromanesh60 | 2012 | Iran | 160 | 100 g OGTT two or more fasting >5.3, 1 hour >10.0, 2 hours, 3 hours >8.6 or 3 hours >7.8 | 50 g OGCT >7.2 | Apgar 5 min, pre-eclampsia, PIH GA at birth, induction, C-section, shoulder dystocia, BW macrosomia, LGA, NICU admission, hypoglycaemia, preterm birth |
| Rowan59 | 2008 | Australia / NZ | 751 | 75g OGTT fasting >5.5 or 2 hours >8.0 | Risk factors | Apgar 5 min <7, BW, GA at birth, LGA, NICU admission, PIH, pre-eclampsia, preterm birth |
| Spaulonci58 | 2013 | Brazil | 94 | 75 g or 100 g OGTT fasting >5.3 or 1 hour >10.0 or 2 hours >8.0 and two or more fasting >5.3, 1 hour >10.0, 2 hours, 3 hours >8.6 or 3 hours >7.8, respectively | No screening | GA at birth, BW, Apgar 5 min, macrosomia, hypoglycaemia, pre-eclampsia, preterm birth, C-section |
| Tertti43 | 2013 | Finland | 217 | 75 g OGTT both criteria: fasting ≥4.8, 1 hour ≥10.0, 2 hours ≥8.7 and fasting ≥5.3, ≥10.0 and ≥8.6, respectively | Risk factors | GA at birth, BW, Apgar at 5 min, induction, instrumental birth, C-section, LGA, macrosomia, preterm birth, PIH, pre-eclampsia, NICU admission, hypoglycaemia |
| Zinnat31 | 2013 | Bangladesh | 450 | Not reported† | Not reported† | Macrosomia, shoulder dystocia, C-section, instrumental birth hypoglycaemia, NICU admission |
*It is assumed unless otherwise reported that the screening strategy advocated by the criteria used was adhered to.
†Conference abstract.
BW, birth weight; C-section, caesarean section; GA, gestational age; GDM, gestational diabetes mellitus; LGA, large for gestational age; NICU, neonatal intensive care unit.