Table 1.
Baseline characteristics
| Valid postal code and valid PA data1 (n = 709) | Missing postal code and/or not valid PA data1 (n = 114) | ||||
|---|---|---|---|---|---|
| Mean | SD | Mean | SD | P-value2 | |
| Age at inclusion (years) | 30.1 | 4.8 | 28.5 | 4.9 | <0.01 |
| BMI pre-pregnancy | 24.5 | 4.6 | 25.5 | 6.0 | 0.04 |
| Socio-economic position (PCA-score) | 0.04 | 1.0 | −0.3 | 1.0 | <0.01 |
| n | % | n | % | P-value3 | |
| Ethnicity | <0.01 | ||||
| Westerna | 308 | (43.4) | 28 | (24.6) | |
| South Asianb | 168 | (23.7) | 32 | (28.1) | |
| Middle Easternc | 105 | (14.8) | 21 | (18.4) | |
| Other ethnicityd | 128 | (18.1) | 33 | (28.9) | |
| Education | 0.02 | ||||
| < 10 years | 108 | (15.3) | 25 | (22.5) | |
| 10–12 years | 274 | (38.8) | 50 | (45.1) | |
| University or college | 324 | (45.9) | 36 | (32.4) | |
| Unknown | 3 | 3 | |||
| Occupation | 0.04 | ||||
| Elementary occupations and homemeakers | 193 | (27.8) | 43 | (39.1) | |
| Clerical/care occupations | 245 | (35.2) | 37 | (33.6) | |
| Manager/degree occupations | 257 | (37.0) | 30 | (27.3) | |
| Unknown | 14 | 4 | |||
| Parity | 0.15 | ||||
| None (nulliparous) | 331 | (46.7) | 50 | (43.9) | |
| 1 (uniparous) | 246 | (34.7) | 34 | (29.8) | |
| ≥ 2 (multiparous) | 132 | (18.6) | 30 | (26.3) | |
| Housing | 0.53 | ||||
| Flat | 566 | (81.0) | 91 | (83.5) | |
| Semi-detached or detached housing | 133 | (19.0) | 18 | (16.5) | |
| Unknown | 10 | 5 | |||
| Health pre-pregnancy | 0.03 | ||||
| Poor/not too good | 71 | (10.1) | 17 | (15.6) | |
| Good | 354 | (50.4) | 62 | (56.9) | |
| Very good | 278 | (39.5) | 30 | (27.5) | |
| Unknown | 6 | 5 | |||
| Smoking behaviour pre-pregnancy | 0.51 | ||||
| Non-smoker | 579 | (82.1) | 94 | (84.7) | |
| Daily or irregular smoker | 126 | (17.9) | 17 | (15.3) | |
| Unknown | 4 | 3 | |||
1 Physical activity data based on ≥2 valid days from ≥1 time point
2 Independent samples t-test
3 Chi-square test
a Valid data (n = 308): 287 from Norway, 13 from Denmark/Sweden, and remaining 9 from Western European countries and North America
b Valid data (n = 168): 110 from Pakistan, 46 from Sri Lanka, 11 from India/Bangladesh
c Valid data (n = 105): 33 from Iraq, 21 from Morocco, 20 from Turkey, 12 from Afghanistan, and remaining 19 from other countries in the region
d Valid data (n = 128): 27 from Somalia, 12 from the Philippines, 14 from Vietnam, remaining 75 from 37 different countries