Table 2.
Odds ratios (ORs)a for thyroid cancer risk in offspring in relation to maternal, paternal, and birth characteristics and maternal and neonatal medical conditions
| Cases (n=2,437) | Controls (n=24,362) | OR | 95% CI | |
|---|---|---|---|---|
| Maternal characteristics | ||||
| Age at birth (years) | ||||
| <25 | 891 (37%) | 8,694 (36%) | 1·00 | Reference |
| 25-29 | 886 (36%) | 8,676 (36%) | 0·99 | 0·90-1·10 |
| 30-39 | 620 (25%) | 6,611 (27%) | 0·91 | 0·82-1·02 |
| 40+ | 40 (2%) | 380 (2%) | 1·02 | 0·73-1·43 |
| Missing | 0 (0%) | 1 (0%) | ||
| Age at birth (per year) | 2,437 (100%) | 24,361 (100%) | 0·99 | 0·99-1·00 |
| Smoking during pregnancy | ||||
| No | 367 (15%) | 3,826 (16%) | 1·00 | Reference |
| Yes | 123 (5%) | 1,150 (5%) | 1·12 | 0·90-1·40 |
| Missing | 1,947 (80%) | 19,386 (80%) | ||
| Marital status | ||||
| Married/co-inhabitant | 1,909 (78%) | 19,196 (79%) | 1·00 | Reference |
| Single/widowed/divorced | 444 (18%) | 4,386 (18%) | 1·02 | 0·90-1·14 |
| Missing | 84 (3%) | 780 (3%) | ||
| Paternal characteristics | ||||
| Age at birth (per year) | 978 (40%) | 9,791 (40%) | 1·00 | 0·99-1·01 |
| Missing | 1,459 (60%) | 14,571 (60%) | ||
| Birth characteristics | ||||
| Preterm birth | ||||
| No | 2,316 (95%) | 23,200 (95%) | 1·00 | Reference |
| Yes | 116 (5%) | 1,148 (5%) | 1·01 | 0·83-1·23 |
| Missing | 5 (0·2%) | 14 (0·1%) | ||
| Multiple birth | ||||
| No | 2,383 (98%) | 23,919 (98%) | 1·00 | Reference |
| Yes | 54 (2%) | 443 (2%) | 1·22 | 0·92-1·63 |
| Cesarean delivery | ||||
| No | 2,254 (92%) | 22,482 (92%) | 1·00 | Reference |
| Yes | 181 (7%) | 1,875 (8%) | 0·96 | 0·82-1·13 |
| Missing | 2 (0·1%) | 5 (0%) | ||
| Small-for-gestational age | ||||
| No | 2,262 (93%) | 22,778 (94%) | 1·00 | Reference |
| Yes | 70 (3%) | 676 (3%) | 1·04 | 0·81-1·34 |
| Missing | 105 (4%) | 908 (4%) | ||
| Large-for-gestational age | ||||
| No | 2,275 (93%) | 22,932 (94%) | 1·00 | Reference |
| Yes | 57 (2%) | 522 (2%) | 1·10 | 0·83-1·45 |
| Missing | 105 (4%) | 908 (4%) | ||
| Birth weight (g) | ||||
| <1,500 | 7 (0·3%) | 88 (0·4%) | 0·85 | 0·39-1·84 |
| 1,500-2,499 | 89 (4%) | 932 (4%) | 1·02 | 0·81-1·27 |
| 2,500-3,499 | 1,096 (45%) | 11,708 (48%) | 1·00 | Reference |
| 3,500-4,499 | 1,171 (48%) | 11,016 (45%) | 1·14 | 1·04-1·24 |
| 4,500+ | 53 (3%) | 514 (2%) | 1·21 | 0·93-1·58 |
| Missing | 9 (0·4%) | 45 (0·2%) | ||
| Birth weight (per kg) | 2,428 (100%) | 24,319 (100%) | 1·14 | 1·05-1·23 |
| Birth order | ||||
| 1 | 1,009 (41%) | 9,756 (40%) | 1·00 | Reference |
| 2 | 897 (37%) | 8,569 (35%) | 1·01 | 0·92-1·11 |
| 3 | 354 (15%) | 3,973 (16%) | 0·86 | 0·76-0·98 |
| 4 | 104 (4%) | 1,330 (5%) | 0·75 | 0·61-0·93 |
| 5+ | 72 (3%) | 716 (3%) | 0·97 | 0·75-1·24 |
| Missing | 1 (0%) | 18 (0·1%) | ||
| Maternal conditions diagnosed before pregnancy | ||||
| Diabetes | 15 (0·6%) | 89 (0·4%) | 1·69 | 0·98-2·93 |
| Hypertension | 2 (0·1%) | 22 (0·1%) | 0·90 | 0·21-3·85 |
| Maternal conditions diagnosed before/during pregnancy (Denmark only) | ||||
| Hypothyroidism | 38 (10%) | 24 (0·6%) | 18·1 | 10·5-31·2 |
| Hyperthyroidism | 27 (7%) | 24 (0·6%) | 11·9 | 6·8-20·9 |
| Goiter | 115 (29%) | 30 (0·8%) | 67·4 | 39·9-114 |
| Thyroiditis | <5b | <5b | 3·33 | 0·90-12·3 |
| Benign thyroid neoplasms | <5b | <5b | 22·5 | 6·93-73·1 |
| Maternal conditions diagnosed during pregnancy | ||||
| Gestational hypertension (yes vs. no) | 31 (1%) | 402 (2%) | 0·77 | 0·53-1·11 |
| Hyperemesis (yes vs. no) | 23 (1%) | 185 (1%) | 1·24 | 0·81-1·92 |
| Pregnancy anemia (yes vs. no) | 20 (1%) | 217 (1%) | 0·92 | 0·58-1·46 |
| Gestational diabetes (yes vs. no) | 9 (0·4%) | 72 (0·3%) | 1·25 | 0·62-2·52 |
| Placental abruption (yes vs. no) | 7 (0·3%) | 86 (0·4%) | 0·81 | 0·37-1·76 |
| Placenta previa (yes vs. no) | 6 (0·2%) | 69 (0·3%) | 0·87 | 0·38-2·01 |
| Preeclampsia/eclampsia (yes vs. no) | 32 (0·1%) | 337 (1%) | 1·03 | 0·78-1·35 |
| Postpartum hemorrhage (yes vs. no) | 132 (5%) | 1,047 (4%) | 1·28 | 1·06-1·55 |
| Neonatal conditions diagnosed in the first year after birth | ||||
| Congenital hypothyroidism (yes vs. no) | 5 (0·2%) | 11 (0·04%) | 4·55 | 1·58-13·1 |
| Neonatal jaundice (yes vs. no) | 27 (1%) | 226 (1%) | 1·20 | 0·80-1·81 |
NE= not estimable
a
From conditional logistic regression models, conditioned on birth year (of the case), sex, country, and county of birth
b
Numbers suppressed due to <5 cases and/or controls