Table 1. Descriptive, socio-economic and behavioral characteristics of study participants (T1 n = 55, T2 n = 92, T3 = 82 and T4 = 78).
| Characteristics | T1 Count (%) 1 | T2 Count (%) 1 | T3 Count (%) 1 | T4 Count (%) 1 | Difference between recruitment time point* |
|---|---|---|---|---|---|
| Age (mean ± SD) | 30±4.8 | 31±5.3 | 31±5.5 | 32±5.5 | p < 0.05 |
| BMI (mean ± SD) | 24±3.9 2 | 25±4.8 | 25±4.4 | 24±4.2 | ns |
| Education | ns | ||||
| Junior high school | 0 (0) | 4 (4.3) | 5 (6.1) | 6 (7.7) | |
| High school | 16 (29.1) | 29 (31.5) | 27 (32.9) | 25 (32.1) | |
| < 4 years of university education 3 | 24 (43.6) | 34 (37.0) | 35 (42.7) | 35 (44.9) | |
| ≥ 4 years of university education 3 | 15 (27.3) | 25 (27.2) | 15 (18.3) | 12 (15.4) | |
| Employment | ns | ||||
| Full-time (80–100%) | 48 (87.3) | 78 (84.8) | |||
| Part-time (50–79%) | 2 (3.6) | 6 (6.5) | NA 4 | NA 4 | |
| Part-time (<50%) | 1 (1.8) | 0 (0) | |||
| Homemaker | 1 (1.8) | 2 (2.2) | |||
| Other | 3 (5.5) | 6 (6.5) | |||
| Marital status | ns | ||||
| Married | 23 (43.4) 1 | 43 (46.7) | NA 4 | NA 4 | |
| Cohabiting | 28 (52.8) | 46 (50.0) | |||
| Single | 2 (3.8) | 3 (3.3) | |||
| Own income in NOK 5 | ns | ||||
| No income | 0 (0) | 2 (2.2) | |||
| < 150.000 | 2 (3.6) | 6 (6.5) | |||
| 150.000–199.999 | 1 (1.8) | 3 (3.3) | NA 4 | NA 4 | |
| 200.000–299.999 | 12 (21.8) | 11 (12.0) | |||
| 300.000–399.999 | 27 (49.1) | 47 (51.1) | |||
| 400.000–499.999 | 10 (18.2) | 14 (15.2) | |||
| > 500.000 NOK | 3 (5.5) | 9 (9.8) | |||
| Breastfeeding | ns | ||||
| Yes | NA | 79 (81.4) | 66 (70.2) | 27 (32.5) | |
| No | 18 (18.6) | 28 (29.8) | 56 (67.5) |
* An independent sample t-test was applied to normal data (age) and Man-Whitney for non-normal data (BMI, education, employment, marital status, own income and breastfeeding)
1 Age and BMI are presented as mean ± SD
2 BMI pre-pregnancy
3 University or University College
4 Data not requested at time point 3 and 4 (no new recruitment)
5 100 000 NOK ≈ 14 000 EUR