. | Control subjects (n = 576) . | Case subjects (n = 189) . |
---|---|---|
Age at end of follow-up (years)* | 11.7 (7.7–17.1) | 12.7 (8.0–16.6)† |
Female sex | 285 (49.5) | 93 (49.2) |
Maternal T1D | 0 (0.0) | 7 (3.7) |
Preterm birth | 19 (3.3) | 10 (5.3) |
Missing data | 1 (0.2) | 1 (0.5) |
Birth weight (g) | ||
<2,500 | 8 (1.4) | 7 (3.7) |
2,500–4,500 | 539 (93.6) | 174 (92.1) |
>4,500 | 29 (5.0) | 8 (4.2) |
Parity | ||
No previous births | 248 (43.1) | 93 (49.2) |
One birth | 215 (37.3) | 57 (30.2) |
Two or more births | 113 (19.6) | 39 (20.6) |
Maternal age (years) | 30 (17–42) | 30 (19–42) |
Maternal non-Norwegian ethnicity | 30 (5.2) | 10 (5.3) |
Maternal smoking during pregnancy | ||
Nonsmoker at end of pregnancy‡ | 469 (81.4) | 161 (85.2) |
Smoked at end of pregnancy | 76 (13.2) | 20 (10.6) |
Missing data | 31 (5.4) | 8 (4.2) |
Maternal prepregnancy BMI (kg/m2) | ||
<25 | 379 (65.8) | 97 (51.3) |
25–30 | 109 (18.9) | 49 (25.9) |
>30 | 40 (6.9) | 28 (14.8) |
Missing data | 48 (8.3) | 15 (7.9) |
Child’s HLA§ genotype | ||
Protective (DQ6) | 168 (29.2) | 3 (1.6) |
Neutral (any other HLA not mentioned) | 111 (19.3) | 5 (2.6) |
Increased risk (≥1 copy of either DQ8 or DQ2) | 212 (36.8) | 93 (49.2) |
High risk (DQ8/DQ2 heterozygote) | 30 (5.2) | 71 (37.6) |
Missing data | 55 (9.5) | 17 (9.0) |
Child’s non-HLA T1D GRS‖ | 61.2 (45.7–76.3) | 63.2 (45.4–78.6) |
Missing data | 19 (3.5) | 12 (6.8) |
Child’s 25(OH)D GRS | 3 (0–8) | 3 (0–8) |
Missing data | 20 (3.7) | 13 (7.4) |
Cesarean section¶ | 59 (10.2) | 36 (19.0) |
. | Control subjects (n = 576) . | Case subjects (n = 189) . |
---|---|---|
Age at end of follow-up (years)* | 11.7 (7.7–17.1) | 12.7 (8.0–16.6)† |
Female sex | 285 (49.5) | 93 (49.2) |
Maternal T1D | 0 (0.0) | 7 (3.7) |
Preterm birth | 19 (3.3) | 10 (5.3) |
Missing data | 1 (0.2) | 1 (0.5) |
Birth weight (g) | ||
<2,500 | 8 (1.4) | 7 (3.7) |
2,500–4,500 | 539 (93.6) | 174 (92.1) |
>4,500 | 29 (5.0) | 8 (4.2) |
Parity | ||
No previous births | 248 (43.1) | 93 (49.2) |
One birth | 215 (37.3) | 57 (30.2) |
Two or more births | 113 (19.6) | 39 (20.6) |
Maternal age (years) | 30 (17–42) | 30 (19–42) |
Maternal non-Norwegian ethnicity | 30 (5.2) | 10 (5.3) |
Maternal smoking during pregnancy | ||
Nonsmoker at end of pregnancy‡ | 469 (81.4) | 161 (85.2) |
Smoked at end of pregnancy | 76 (13.2) | 20 (10.6) |
Missing data | 31 (5.4) | 8 (4.2) |
Maternal prepregnancy BMI (kg/m2) | ||
<25 | 379 (65.8) | 97 (51.3) |
25–30 | 109 (18.9) | 49 (25.9) |
>30 | 40 (6.9) | 28 (14.8) |
Missing data | 48 (8.3) | 15 (7.9) |
Child’s HLA§ genotype | ||
Protective (DQ6) | 168 (29.2) | 3 (1.6) |
Neutral (any other HLA not mentioned) | 111 (19.3) | 5 (2.6) |
Increased risk (≥1 copy of either DQ8 or DQ2) | 212 (36.8) | 93 (49.2) |
High risk (DQ8/DQ2 heterozygote) | 30 (5.2) | 71 (37.6) |
Missing data | 55 (9.5) | 17 (9.0) |
Child’s non-HLA T1D GRS‖ | 61.2 (45.7–76.3) | 63.2 (45.4–78.6) |
Missing data | 19 (3.5) | 12 (6.8) |
Child’s 25(OH)D GRS | 3 (0–8) | 3 (0–8) |
Missing data | 20 (3.7) | 13 (7.4) |
Cesarean section¶ | 59 (10.2) | 36 (19.0) |
Data are median (range) or n (%).
*Diagnosis date of the last case subject included: 3 February 2014.
†Median age at diagnosis of T1D case subjects was 5.7 years (range 0.7–12.7).
‡Including those who quit smoking shortly before or during pregnancy.
§Groups defined as protective (carrying at least one copy of HLA DQA1*01:02-DQB1*06:02-DRB1*15:01 [DQ6-DR15]), increased risk (at least one copy of HLA DQA1*03-DQB1*03:02-DRB1*04 [DQ8-DR4] or DQA1*05:01-DQB1*02:01-DRB1*03:01 [DQ2-DR3] but not both haplotypes), high risk (HLA DQ2-DR3/DQ8-DR4), or neutral (any other genotype).
‖Weighted score, calculated by multiplying the number of risk alleles in 51 non-HLA SNPs with their reported risk per allele.
¶Includes unknown (n = 1), emergency (n = 55), and elective (n = 39) cesarean section.