Table 3.
Meta-analysis of randomized controlled trials comparing outcomes from treatment with metformin v glibenclamide in women with gestational diabetes
| Outcomes | No of studies | No of patients treated | Mean difference (95% CI) | Relative risk (95% CI) | P value | I2 value | |
|---|---|---|---|---|---|---|---|
| With metformin | With glibenclamide | ||||||
| Primary outcomes | |||||||
| HbA1c level at end of third trimester (%) | 1 | 104 | 96 | −0.11 (−0.34 to 0.12) | — | 0.34 | — |
| Severe maternal hypoglycaemia (%) | 1 | 104 | 96 | — | 0 v 0 | — | — |
| Pre-eclampsia (%) | 2 | 179 | 170 | — | 0.95 (0.28 to 3.25) | 0.94 | 0 |
| Maternal weight gain (kg) | 1 | 104 | 96 | −2.06 (−3.98 to −0.14) | — | 0.04 | — |
| Caesarean section (%) | 2 | 179 | 170 | — | 1.99 (0.32 to 12.4)* | 0.46 | 84 |
| Treatment failure (%) | 2 | 179 | 170 | — | 1.23 (0.42 to 3.54)* | 0.71 | 87 |
| Gestational age at delivery (weeks) | 2 | 179 | 170 | −0.11 (−0.40 to 0.19) | — | 0.47 | 0 |
| Preterm birth (%) | 1 | 104 | 96 | — | 1.15 (0.32 to 4.17) | 0.83 | — |
| Birth weight (g) | 2 | 179 | 170 | −209 (−314 to −104) | — | <0.001 | 0 |
| Macrosomia (%) | 2 | 179 | 170 | — | 0.33 (0.13 to 0.81) | 0.02 | 0 |
| Large for gestational age (%) | 1 | 104 | 96 | — | 0.44 (0.21 to 0.92) | 0.03 | — |
| Small for gestational age (%) | 1 | 104 | 96 | — | 1.23 (0.28 to 5.36) | 0.78 | — |
| Any neonatal hypoglycaemia (%) | 2 | 178 | 169 | — | 0.86 (0.42 to 1.77) | 0.68 | 0 |
| Perinatal mortality (%) | 1 | 104 | 96 | — | 0.92 (0.06 to 14.6) | 0.95 | — |
| Secondary outcomes | |||||||
| Fasting blood glucose (mmol/L) | 2 | 179 | 170 | 0.15 (0.00 to 0.30) | — | 0.04 | 0 |
| Postprandial blood glucose (mmol/L) | 2 | 179 | 170 | −0.04 (−0.27 to 0.19) | — | 0.74 | 0 |
| Maternal weight gain since entry (kg) | 0 | — | — | — | — | — | — |
| Pregnancy induced hypertension (%) | 0 | — | — | — | — | — | — |
| Induction (%) | 0 | — | — | — | — | — | — |
| Cord C peptide (nmol/L) | 0 | — | — | — | — | — | — |
| Cord insulin (pmol/L) | 0 | — | — | — | — | — | — |
| 1 minute Apgar score <7 (%) | 1 | 103 | 95 | — | 0.46 (0.04 to 5.00) | 0.52 | — |
| 5 minute Apgar score <7 (%) | 2 | 178 | 169 | — | 2.77 (0.10 to 67.2) | 0.53 | — |
| Obstetric trauma (%) | 0 | — | — | — | — | — | — |
| Severe neonatal hypoglycaemia† (%) | 0 | — | — | — | — | — | — |
| Neonatal jaundice (%) | 0 | — | — | — | — | — | — |
| Neonatal respiratory distress syndrome (%) | 0 | — | — | — | — | — | — |
| Stillbirth (%) | 1 | 104 | 96 | — | 0.92 (0.06 to 14.6) | 0.95 | — |
| Neonatal mortality (%) | 1 | 103 | 95 | — | 0 v 0 | — | — |
| NICU admission (%) | 2 | 178 | 169 | — | 1.52 (0.65 to 3.55) | 0.33 | 1 |
I2=Heterogeneity. HbA1c= glycated haemoglobin. NICU=neonatal intensive care unit.
*Estimated using a random effects model because I2>50%
†Defined by authors or requiring intravenous glucose or NICU admittance.