Table 1.
Characteristics of the study population, n = 7,915
| Maternal age (years) | n/(%)* |
| <25 | 394 (5.0) |
| 25-29 | 2342 (29.6) |
| 30-34 | 3160 (39.9) |
| 35-39 | 1650 (20.8) |
| ≥40 | 350 (4.4) |
| Parity | |
| Nulliparous | 4717 (59.6) |
| Multiparous | 3157 (39.9) |
| Degree of pregnancy planning | |
| Very planned | 3506 (44.3) |
| Rather planned | 2135 (27.0) |
| Neither planned nor unplanned | 1270 (16.0) |
| Rather unplanned | 354 (4.5) |
| Very unplanned | 313 (4.0) |
| Method of conception | |
| Spontaneous | 6656 (84.1) |
| Assisted reproductive technology | 894 (11.3) |
| Smoking before pregnancy | |
| Yes | 758 (9.6) |
| No | 6712 (84.8) |
| Physical exercise before pregnancy | |
| Yes | 5675 (71.7) |
| No | 2240 (28.3) |
| Body mass index (kg/m2) | |
| <18.5 | 409 (5.2) |
| 18.5-24.9 | 5610 (70.9) |
| 25-29.9 | 942 (11.9) |
| ≥30 | |
| Disorders | |
| Chronic disorders* | 948 (12.0) |
| Mental disorders | 189 (2.4) |
| None | 5725 (72.3) |
| Other disorders¤ | 558 (7.0) |
| Reads and understands Danish language | |
| Yes | 7505 (94.8) |
| No | 349 (4.4) |
| Educational level | |
| Advanced degree | 3561 (45.0) |
| 3-4 years higher education | 2267 (28.6) |
| 1-2 years higher education | 511 (6.5) |
| Skilled worker | 251 (3.2) |
| No education | 524 (6.6) |
| Occupation | |
| Employed | 5297 (66.9) |
| Unemployed | 469 (5.9) |
| Student | 1182 (14.9) |
| Other† | 275 (3.5) |
*Chronic diseases; Hypertension, cardiac diseases, pulmonary diseases, diabetes, metabolic disorders, arthritis, epilepsy and migraine.
¤Other diseases reported were e.g. skin diseases, systemic lupus erythematosis, celiac disease, inflammatory bowel disease, hepatitis, gallstones, multiple sclerosis, thrombophilia, and polycystic ovarian syndrome.
†Including stay at home mothers, pensioners and women on maternity leave.
Due to missing data in some categories will the sum of women differ between categories.