Associations between pregestational glucose and adverse pregnancy outcomes
| Hypoglycaemia (<3.9 mmol/L) | Normoglycaemia (3.9–6.0 mmol/L) | Hyperglycaemia (≥6.1 mmol/L) | ||
| IFG (6.1–6.9 mmol/L) | Diabetic (≥7.0 mmol/L) | |||
| Among 60 360 pregnancies that had pregnancy outcomes | ||||
| Spontaneous abortion | ||||
| No. (%) | 133 (4.36) | 3204 (5.94) | 115 (4.15) | 34 (5.39) |
| Unadjusted RR (95% CI) | 0.73 (0.62 to 0.87) | 1.00 | 0.70 (0.58 to 0.84) | 0.91 (0.65 to 1.27) |
| Adjusted RR* (95% CI) | 0.79 (0.66 to 0.93) | 1.00 | 0.68 (0.57 to 0.82) | 0.81 (0.57 to 1.13) |
| Induced abortion/labour due to medical reasons | ||||
| No. (%) | 82 (2.69) | 1703 (3.16) | 54 (1.95) | 18 (2.85) |
| Unadjusted RR (95% CI) | 0.85 (0.68 to 1.06) | 1.00 | 0.62 (0.47 to 0.81) | 0.90 (0.57 to 1.44) |
| Adjusted RR* (95% CI) | 0.92 (0.74 to 1.15) | 1.00 | 0.62 (0.47 to 0.81) | 0.82 (0.51 to 1.30) |
| Stillbirth | ||||
| No. (%) | 6 (0.20) | 115 (0.21) | 4 (0.14) | 3 (0.48) |
| Unadjusted RR (95% CI) | 0.92 (0.41 to 2.09) | 1.00 | 0.68 (0.25 to 1.83) | 2.23 (0.71 to 7.01) |
| Adjusted RR* (95% CI) | 0.88 (0.39 to 2.01) | 1.00 | 0.68 (0.25 to 1.84) | 2.08 (0.66 to 6.60) |
| Among 54 365 pregnancies with singleton live births | ||||
| Preterm births | ||||
| No. (%) | 217 (7.73) | 3565 (7.38) | 149 (5.78) | 44 (7.72) |
| Unadjusted RR (95% CI) | 1.05 (0.91 to 1.20) | 1.00 | 0.78 (0.67 to 0.92) | 1.05 (0.78 to 1.41) |
| Adjusted RR† (95% CI) | 1.03 (0.90 to 1.18) | 1.00 | 0.78 (0.67 to 0.92) | 1.04 (0.77 to 1.40) |
| Very preterm births | ||||
| No. (%) | 33 (1.18) | 602 (1.25) | 19 (0.74) | 6 (1.05) |
| Unadjusted RR (95% CI) | 0.94 (0.66 to 1.34) | 1.00 | 0.59 (0.37 to 0.93) | 0.84 (0.38 to 1.89) |
| Adjusted RR† (95% CI) | 0.94 (0.66 to 1.34) | 1.00 | 0.59 (0.37 to 0.93) | 0.79 (0.35 to 1.76) |
| Macrosomia | ||||
| No. (%) | 128 (4.60) | 1992 (4.16) | 110 (4.32) | 35 (6.18) |
| Unadjusted RR (95% CI) | 1.11 (0.93 to 1.32) | 1.00 | 1.04 (0.86 to 1.26) | 1.49 (1.06 to 2.08) |
| Adjusted RR† (95% CI) | 1.17 (0.98 to 1.40) | 1.00 | 1.07 (0.88 to 1.29) | 1.49 (1.07 to 2.09) |
| LGA | ||||
| No. (%) | 285 (10.25) | 4692 (9.81) | 237 (9.33) | 61 (10.80) |
| Unadjusted RR (95% CI) | 1.04 (0.93 to 1.18) | 1.00 | 0.95 (0.83 to 1.08) | 1.10 (0.85 to 1.42) |
| Adjusted RR† (95% CI) | 1.06 (0.94 to 1.20) | 1.00 | 0.97 (0.85 to 1.10) | 1.09 (0.84 to 1.40) |
| LBW | ||||
| No. (%) | 40 (1.44) | 564 (1.18) | 15 (0.59) | 7 (1.24) |
| Unadjusted RR (95% CI) | 1.22 (0.89 to 1.68) | 1.00 | 0.50 (0.30 to 0.84) | 1.05 (0.50 to 2.21) |
| Adjusted RR† (95% CI) | 1.22 (0.88 to 1.67) | 1.00 | 0.52 (0.31 to 0.86) | 1.10 (0.52 to 2.32) |
| SGA | ||||
| No. (%) | 170 (6.12) | 2832 (5.92) | 109 (4.29) | 28 (4.96) |
| Unadjusted RR (95% CI) | 1.03 (0.89 to 1.21) | 1.00 | 0.72 (0.60 to 0.88) | 0.84 (0.58 to 1.21) |
| Adjusted RR† (95% CI) | 1.02 (0.87 to 1.19) | 1.00 | 0.72 (0.60 to 0.88) | 0.86 (0.59 to 1.25) |
*Adjusted RR were adjusted for maternal age, maternal pregestational BMI, ethnicity, education level, occupation, place of residence, smoking, passive smoking, alcohol, parity, gravidity, history of preterm birth, history of spontaneous abortion, history of induced abortion and hypertension.
†Adjusted RR were additionally adjusted for neonate sex.
IFG, impaired fasting glycaemia; LBW, low birth weight; LGA, large for gestational age; RR, risk ratio; SGA, small for gestational age.