Table 1 Characteristics of children by type 1 diabetes status in different study designs^a

Overall

2,976,704 (99.4)

18,617 (0.6)

21,036 (72.5)

7988 (27.5)

21,302 (59.9)

14,284 (40.1)

Boys

1,529,498 (51.4)

10,166 (54.6)

10,729 (51.0)

4399 (55.1)

10,908 (51.2)

7816 (54.7)

Year of birth

 1983–1984

164,968 (5.5)

888 (4.8)

1141 (5.4)

302 (3.8)

799 (3.8)

451 (3.2)

 1985–1989

469,384 (15.8)

2811 (15.1)

3800 (18.1)

12,203 (15.1)

3537 (16.6)

2053 (14.4)

 1990–1994

534,392 (18.0)

3892 (20.9)

4918 (23.4)

1849 (23.1)

5038 (23.7)

3236 (22.7)

 1995–1999

407,468 (13.7)

3404 (18.3)

3769 (17.9)

1476 (18.5)

4192 (19.7)

2790 (19.5)

 2000–2004

421,330 (14.2)

3533 (19.0)

3436 (16.3)

1531 (19.2)

3782 (17.8)

2842 (19.9)

 2005–2009

468,632 (15.7)

2696 (14.5)

2624 (12.5)

1090 (13.6)

2656 (12.5)

2032 (14.2)

 2010–2014

510,530 (17.2)

1393 (7.5)

1348 (6.4)

537 (6.7)

1298 (6.1)

80 (6.2)

Gestational age in days, mean (SD)

278.8 (12.2)

277.9 (12.2)

278.4 (12.4)

278.0 (12.0)

278.3 (12.0)

278.0 (12.0)

Birth weight for gestational age

 Small for gestational age

70,763 (2.4)

382 (2.1)

466 (2.2)

167 (2.1)

388 (1.8)

267 (1.9)

 Normal

2,793,435 (93.8)

17,350 (93.2)

19,663 (93.5)

7466 (93.5)

19,783 (92.9)

13,316 (93.2)

 Large for gestational age

103,661 (3.5)

834 (4.5)

850 (4.0)

337 (4.2)

1066 (5.0)

666 (4.7)

 Unknown

8845 (0.3)

51 (0.3)

57 (0.3)

18 (0.2)

65 (0.3)

35 (0.2)

Birth order

 1

1,265,549 (42.5)

7851 (42.2)

8667 (41.2)

3273 (41.0)

7523 (35.3)

5203 (36.4)

 2

1,082,395 (36.4)

6833 (36.7)

7545 (35.9)

2966 (37.1)

7617 (35.8)

5796 (40.6)

 3 + 

628,760 (21.1)

3933 (21.1)

4824 (22.9)

1749 (21.9)

6162 (28.9)

3285 (23.0)

Maternal age at delivery in years, mean (SD)

29.7 (5.2)

29.7 (5.1)

28.8 (5.1)

29.4 (5.1)

29.0 (5.1)

29.5 (5.0)

Maternal marital status

 Living with child’s father

2,751,651 (92.4)

17,282 (92.8)

19,354 (92.0)

7420 (92.9)

19,788 (92.9)

13,362 (93.5)

 Single

56,402 (1.9)

330 (1.8)

452 (2.1)

151 (1.9)

347 (1.6)

227 (1.6)

 Others

89,494 (3.0)

482 (2.6)

641 (3.0)

196 (2.5)

553 (2.6)

293 (2.1)

 Unknown

79,157 (2.7)

523 (2.8)

589 (2.8)

221 (2.8)

614 (2.9)

402 (2.8)

Maternal educational level

 Pre-secondary

386,663 (13.0)

2343 (12.6)

2799 (13.3)

980 (12.3)

2705 (12.7)

1600 (11.2)

 Upper-secondary

567,201 (19.1)

4343 (23.3)

5282 (25.1)

2105 (26.4)

5108 (24.0)

3459 (24.2)

 High school

567,452 (19.1)

3573 (19.2)

3684 (17.5)

1495 (18.7)

3764 (17.7)

2736 (19.2)

 Post-secondary or higher

914,211 (30.7)

5387 (28.9)

5018 (23.9)

2127 (26.6)

5547 (26.0)

4198 (29.4)

 Unknown

541,177 (18.2)

2971 (16.0)

4253 (20.2)

1281 (16.0)

4178 (19.6)

2291 (16.0)

Paternal educational level

 Pre-secondary

492,235 (16.5)

2975 (16.0)

3597 (17.1)

1258 (15.7)

3213 (15.1)

2098 (14.7)

 Upper-secondary

716,097 (24.1)

5451 (29.3)

62,200 (29.5)

2491 (31.2)

6296 (29.6)

4334 (30.3)

 High school

547,304 (18.4)

3226 (17.3)

3287 (15.6)

1344 (16.8)

3312 (15.5)

2372 (16.6)

 Post-secondary or higher

785,763 (26.4)

4607 (24.7)

4347 (20.7)

1828 (22.9)

5002 (23.5)

3645 (25.5)

 Unknown

435,305 (14.6)

2358 (12.7)

3605 (17.1)

1067 (13.4)

3479 (16.3)

1835 (12.8)

Maternal BMI in kg/m² during pregnancy^b, mean (SD)

23.9 (4.3)

24.1 (4.3)

23.9 (4.3)

24.2 (4.3)

24.1 (4.5)

24.1 (4.3)

Maternal cesarean section at delivery

399,662 (13.4)

2724 (14.6)

2595 (12.3)

1107 (13.9)

2576 (12.1)

1890 (13.2)

Maternal diabetes at childbirth^c

24,923 (0.8)

593 (3.2)

340 (1.6)

256 (3.2)

560 (2.6)

392 (2.7)

Paternal diabetes at childbirth

21,731 (0.7)

865 (4.6)

123 (0.6)

371 (4.6)

760 (3.6)

623 (4.4)

Maternal asthma at childbirth

158,268 (5.3)

1085 (5.8)

1093 (5.2)

475 (5.9)

1141 (5.4)

815 (5.7)

Paternal asthma at childbirth

35,258 (1.2)

237 (1.3)

202 (1.0)

114 (1.4)

259 (1.2)

171 (1.2)