Table 1.
Selected study characteristics of study subjects (Umeå, Sweden, 1975–2008).
| Characteristic | Cases (n = 159) | Controls (n = 286) | p-value* |
|---|---|---|---|
| Age at blood draw, years (range) | 26.8 (18.3–39.0) | 26.6 (18.3–39.2) | – |
| Gestational day (range) | 72.0 (38.0–105.0) | 71.0 (42.0–118.0) | 0.68 |
| Parity at diagnosis | – | – | 0.18 |
| − 1, n (%) | 38 (24%) | 56 (20%) | – |
| − 2, n (%) | 82 (52%) | 145 (50%) | – |
| − ≥2, n (%) | 39 (24%) | 85 (30%) | – |
| Child's gender | – | – | 0.63 |
| − Male, n (%) | 90 (57%) | 155 (54%) | – |
| − Female, n (%) | 69 (43%) | 131 (46%) | – |
| Child's weight, g (range) | 3470 (2520–4680) | 3485 (2115–4770) | 0.13 |
| Child's length, cm (range) | 50.0 (37.0–56.0) | 50.0 (45.5–57.0) | 0.61 |
| Smoking | – | – | 0.41 |
| − No, n (%) | 107 (67%) | 204 (71%) | – |
| − Yes, n (%) | 52 (33%) | 81 (28%) | – |
| BMI, kg/m2 (range) | 22.0 (17.7–30.5) | 22.2 (16.8–45.0) | 0.36 |
| Age at diagnosis, years (range) | 44.8 (25.5–60.8) | – | – |
| Lag-time, years (range) | 17.8 (2.7–28.6) | – | – |
| Hormones† | – | – | – |
| − hCG(mU/ml) | 94,989 (57,757–140,430) | 97,355 (55,016–141,279) | 0.52 |
| − Free β-hCG (ng/ml) | 726 (68–1741) | 803 (62–1942) | 0.28 |
*
p-values calculated by conditional logistic regression.
†
Mean levels (10th–90th percentile) corresponding to hCG and free β-hCG concentrations centred at the median gestational day (71).
hCG: Human chorionic gonadotropin.