Table 2.
Association between type 1 diabetes in mothers and risk of major birth defects in offspring, according to glycated haemoglobin levels within three months before or after estimated conception
| Variables | No diabetes | Type 1 diabetes overall | Type 1 diabetes by glycated haemoglobin levels | ||||
|---|---|---|---|---|---|---|---|
| <6.5% | 6.5% to <7.8% | 7.8% to <9.1% | ≥9.1% | ||||
| No of infants | 1 159 865 | 2458 | 549 | 1120 | 541 | 248 | |
| Major cardiac defects: | |||||||
| No of events | 17 120 | 122 | 18 | 55 | 24 | 25 | |
| No of events per 1000 infants | 15 | 50 | 33 | 49 | 44 | 101 | |
| Unadjusted risk ratio (95% CI) | 1.00 (ref) | 3.37 (2.83 to 4.00) | 2.23 (1.42 to 3.52) | 3.33 (2.58 to 4.31) | 2.99 (2.03 to 4.40) | 6.82 (4.72 to 9.85) | |
| Adjusted risk ratio (95% CI)* | 1.00 (ref) | 3.19 (2.69 to 3.80) | 2.17 (1.37 to 3.42) | 3.17 (2.45 to 4.11) | 2.79 (1.90 to 4.12) | 6.23 (4.32 to 9.00) | |
| Unadjusted risk difference, No of events (95% CI) per 1000 infants | - | 35 (27 to 44) | 18 (6 to 37) | 34 (23 to 49) | 29 (15 to 50) | 86 (55 to 131) | |
| Adjusted risk difference, No of events (95% CI) per 1000 infants* | - | 32 (25 to 41) | 17 (5 to 36) | 32 (21 to 46) | 26 (13 to 46) | 77 (49 to 118) | |
| Major non-cardiac defects: | |||||||
| No of events | 20 960 | 50 | 12 | 21 | 9 | 8 | |
| No of events per 1000 infants | 18 | 20 | 22 | 19 | 17 | 32 | |
| Unadjusted risk ratio (95% CI) | 1.00 (ref) | 1.13 (0.85 to 1.49) | 1.21 (0.69 to 2.10) | 1.04 (0.68 to 1.59) | 0.92 (0.48 to 1.76) | 1.79 (0.90 to 3.54) | |
| Adjusted risk ratio (95% CI)* | 1.00 (ref) | 1.09 (0.82 to 1.44) | 1.18 (0.68 to 2.07) | 1.01 (0.66 to 1.54) | 0.89 (0.46 to 1.69) | 1.68 (0.85 to 3.33) | |
| Unadjusted risk difference, No of events (95% CI) per 1000 infants | - | 2 (−3 to 9) | 4 (−6 to 20) | 1 (−6 to 11) | −1 (−9 to 14) | 14 (−2 to 46) | |
| Adjusted risk difference, No of events (95% CI) per 1000 infants* | - | 2 (−3 to 8) | 3 (−6 to 19) | 0 (−6 to 10) | −2 (−10 to 12) | 12 (−3 to 42) | |
*
Adjusted for calendar year, maternal age, country of birth, living with partner, education, parity, body mass index, smoking status, and other autoimmune disease.