The risk of spontaneous abortion according to educational level, income level and labour market attachment, respectively, in the Danish National Birth Cohort
| No. of events | Crude | Age adjusted | |
| HR (95% CI) | HR (95% CI) | ||
| Educational level (n=88 958) | |||
| BA or more (>12 years) | 589 | 1 | |
| Higher education (less than BA degree) | 1239 | 1.01 (0.92 to 1.11) | 1.02 (0.93 to 1.13) |
| Upper secondary education and vocational training | 1668 | 0.97 (0.88 to 1.06) | 1.01 (0.92 to 1.11) |
| Compulsory school (<10 years) | 527 | 1.14 (1.01 to 1.28) | 1.19 (1.05 to 1.34) |
| Income quintile (n=88 602) | |||
| >80% | 785 | 1 | 1 |
| 60%–80% | 787 | 1.01 (0.91 to 1.11) | 1.1 (0.99 to 1.21) |
| 40%–60% | 796 | 1.03 (0.93 to 1.13) | 1.15 (1.04 to 1.27) |
| 20%–40% | 740 | 0.93 (0.84 to 1.03) | 1.09 (0.99 to 1.22) |
| <20% | 773 | 0.95 (0.86 to 1.05) | 1.15 (1.03 to 1.27) |
| Employment status (n=84 306) | |||
| Employed | 3398 | 1 | 1 |
| Student | 295 | 0.91 (0.81 to 1.03) | 1.03 (0.91 to 1.16) |
| Unemployed (>50% of the year) | 128 | 1.04 (0.87 to 1.25) | 1.01 (0.84 to 1.20) |
| Disability pension | 17 | 1.61 (1.00 to 2.60) | 1.32 (0.82 to 2.13) |
Risks are expressed in HR.