Table 1:
Characteristics by status of gestational diabetes mellitus in mother
| Characteristic | No. with gestational diabetes (%)* n = 36 590 |
No. without gestational diabetes (%)* n = 36 590 |
Standardized difference |
|---|---|---|---|
| Female sex | 17 495 (47.8) | 17 694 (48.4) | −0.011 |
| Gestational age, wk | |||
| Mean gestational age at birth ± SD | 38.6 ± 1.74 | 39.1 ± 1.83 | −0.285 |
| Gestational age category | |||
| < 32 | 485 (1.3) | 525 (1.4) | −0.009 |
| 32–37 | 2884 (7.9) | 1920 (5.3) | 0.107 |
| > 37 | 32 221 (90.8) | 34 145 (93.3) | −0.094 |
| Weight status at birth, g | |||
| Mean birth weight ± SD | |||
| Overall | 3372 ± 0.562 | 3351 ± 0.532 | 0.039 |
| Girls | 3316 ± 0.541 | 3289 ± 0.511 | 0.0523 |
| Boys | 3424 ± 0.576 | 3410 ± 0.545 | 0.0252 |
| Birth weight category† | |||
| Low birth weight, < 2500 | 2035 (5.6) | 1794 (4.9) | 0.030 |
| < 2500 to < 2999 | 5808 (15.9) | 6013 (16.5) | −0.015 |
| Normal birth weight, 3000 to 3999 | 24 391 (66.8) | 25 220 (69.1) | −0.049 |
| Macrosomia, ≥ 4000 | 4263 (11.7) | 3474 (9.5) | 0.070 |
| Ethnocultural background‡ | |||
| European§ | 28 035 (76.6) | 29 892 (81.7) | −0.125 |
| Indigenous | 303 (0.83) | 140 (0.38) | 0.0575 |
| Afro-Caribbean | 1343 (3.7) | 1110 (3.0) | 0.0354 |
| Asian¶ | 2809 (7.7) | 1631 (4.5) | 0.135 |
| Central/South American | 542 (1.5) | 597 (1.6) | −0.0121 |
| West Asian | 2249 (6.2) | 1847 (5.1) | 0.0478 |
| Other | 1094 (3.0) | 1125 (3.1) | −0.0049 |
| Maternal age categories, yr | |||
| < 30 | 16 374 (44.8) | 16 374 (44.8) | 0 |
| 30–40 | 18 924 (51.7) | 18 924 (51.7) | 0 |
| > 40 | 1292 (3.5) | 1292 (3.5) | 0 |
| Maternal education, yr** | |||
| < 12 | 8861 (25.7) | 6593 (19.1) | 0.158 |
| 12–14 | 8326 (24.1) | 7537 (21.8) | 0.054 |
| 14–18 | 13 907 (40.3) | 15 780 (45.7) | −0.110 |
| > 18 | 3454 (10) | 4620 (13.3) | −0.105 |
| Maternal deprivation level, quintiles†† | |||
| 2 least deprived quintiles | 12 751 (35.8) | 14 648 (41.2) | −0.111 |
| 2 quintiles at intermediate level | 14 431 (40.5) | 14 011 (39.4) | 0.0224 |
| Most deprived quintile | 8461 (23.7) | 6911 (19.4) | 0.105 |
| Maternal pregnancy history | |||
| Prior pregnancy | 18 777 (51.3) | 10 521 (28.8) | 0.473 |
| Prior stillbirth | 1379 (3.8) | 932 (2.6) | 0.07 |
| Prior viable pregnancies | |||
| 0 | 18 293 (50) | 26 474 (72.4) | −0.471 |
| 1 | 11 590 (31.7) | 6441 (17.6) | 0.331 |
| ≥ 2 | 6707 (18.3) | 3675 (10.0) | 0.239 |
| Maternal autoimmune disease‡‡ | 10 955 (29.9) | 9812 (26.8) | 0.0693 |
Note: SD = standard deviation.
Unless stated otherwise.
Missing for 9.
Missing for 5135.
European is defined as born in North America, Europe or Australia, with European first language.
South Asian, Southeast Asian and East Asian origin.
Missing for 4102.
Missing for 1967.
The autoimmune diseases considered included multiple sclerosis, celiac disease, sarcoidosis, Behçet syndrome, thyroid conditions, Cushing syndrome, hyperaldosteronism, primary thrombocytopenia, various types of allergic alveolitis, eosinophilic pneumonitis, psoriasis, urticaria, bullous pemphigoid, lupus, scleroderma, dermatomyositis, polymyositis, rheumatoid arthritis, sacroilliitis, ankylosing spondylitis, inflammatory bowel disease and myasthenia gravis.