Table 1.
Characteristics of cohort at stratified by eligibility for analysis
| Valid SWA data (eligible) | Without valid SWA data (not eligible) | ||||
|---|---|---|---|---|---|
| (n = 555) | (n = 268) | ||||
| n | % | n | % | P-value a | |
| Ethnicity | <0.01 | ||||
| South Asian | 125 | (22.5) | 75 | (28.0) | |
| Middle Eastern | 75 | (13.5) | 51 | (19.0) | |
| Other ethnicity | 100 | (18.0) | 61 | (22.8) | |
| Western | 255 | (46.0) | 81 | (30.2) | |
| Occupation | 0.20 | ||||
| Elementary occupations and homemakers | 150 | (27.4) | 86 | (33.5) | |
| Clerical/care occupations | 196 | (35.8) | 86 | (33.5) | |
| Manager/° occupations | 202 | (36.8) | 85 | (33.0) | |
| Missing | 7 | 11 | |||
| Education | 0.39 | ||||
| <10 years | 85 | (15.4) | 48 | (18.2) | |
| 10–12 years | 216 | (39.0) | 108 | (40.9) | |
| University or college | 252 | (45.6) | 108 | (40.9) | |
| Missing | 2 | 4 | |||
| Parity | 0.11 | ||||
| None (nulliparous) | 253 | (45.6) | 128 | (47.8) | |
| 1 (uniparous) | 201 | (36.2) | 79 | (29.5) | |
| ≥2 (multiparous) | 101 | (18.2) | 61 | (22.7) | |
| Smoking 3 months pre-pregnancy | 0.96 | ||||
| Non-smoker | 455 | (82.4) | 218 | (82.6) | |
| Irregular or daily smoker | 97 | (17.6) | 46 | (17.4) | |
| Missing | 3 | 4 | |||
| Self-reported pre-pregnancy PA | 0.16 | ||||
| ≥150 min/wk | 220 | (40.6) | 91 | (35.4) | |
| <150 min/wk | 322 | (59.4) | 166 | (64.6) | |
| Missing | 13 | 11 | |||
| Health pre-pregnancy | 0.78 | ||||
| Poor/not too good | 58 | (10.6) | 30 | (11.5) | |
| Good | 279 | (50.7) | 137 | (52.3) | |
| Very good | 213 | (38.7) | 95 | (36.2) | |
| Missing | 5 | 6 | |||
| Pelvic girdle-/lumbopelvic pain | 0.87 | ||||
| Yes | 228 | (41.8) | 107 | (41.2) | |
| No | 318 | (58.2) | 153 | (58.8) | |
| Missing | 9 | 8 | |||
| Mean | SD | Mean | SD | P-value b | |
| Age (years) | 30.1 | (4.9) | 29.3 | (4.8) | 0.02 |
| BMI pre-pregnancy | 24.4 | (4.8) | 25.0 | (4.9) | <0.01 |
| Body fat percentage | 33.1 | (7.4) | 34.5 | (7.3) | 0.15 |
SD standard deviation, SWA Sensewear Armband, BMI body mass index
a Chi-Square test
b t-test