Table 1.
Comparison of SWS mother-child pairs included in the analysis compared with those not included because of either incomplete follow up at 6 or 12 months or missing maternal BMI data.
| Participating mother-child pairs (n=2799) | Mother-child pairs with missing data (n=359) | P-value | ||
|---|---|---|---|---|
| Maternal characteristics | ||||
| Age at child’s birth, years (mean (SD)) | 30.7 (3.8) | 30.6 (4.0) | 0.8 | |
| Height, cm (mean (SD)) | 163.3 (6.5) | 162.7 (6.4) | 0.2 | |
| Primiparous (n (%)) | ||||
| No | 1445 (51.7) | 167 (46.7) | 0.07 | |
| Yes | 1352 (48.3) | 191 (53.4) | ||
| Qualifications (n (%)) | None | 81 (2.9) | 18 (5.0) | 0.02 |
| GCSE D-G | 252 (9.0) | 43 (12.0) | ||
| GCSE A*-C | 810 (29.0) | 101 (28.2) | ||
| A Level | 845 (30.3) | 108 (30.2) | ||
| HND | 183 (6.6) | 15 (4.2) | ||
| Degree | 620 (22.2) | 73 (20.4) | ||
| Smoked in pregnancy (n (%)) | ||||
| No | 2278 (84.5) | 227 (77.2) | 0.001 | |
| Yes | 418 (15.5) | 67 (22.8) | ||
| Maternal asthma (n (%)) | ||||
| No | 1949 (77.2) | 243 (82.9) | 0.03 | |
| Yes | 576 (22.8) | 50 (17.1) | ||
| Measured maternal BMI, kgm-2 (median, (IQR)) | 24.1 (21.9, 27.4) | 24.4 (21.7, 27.5) | 0.8 | |
| Paternal characteristics | ||||
| Age at child’s birth, years (mean (SD)) | 33.2 (5.4) | 33.0 (5.7) | 0.5 | |
| Height, cm (mean (SD)) | 179.1 (7.3) | 178.6 (6.8) | 0.2 | |
| Paternal asthma (n (%)) | ||||
| No | 2031 (81.3) | 242 (84.0) | 0.3 | |
| Yes | 466 (18.7) | 46 (16.0) | ||
| Paternal BMI, kg m-2 (median (IQR) | 25.5 (23.5, 27.8) | 25.5 (23.4, 27.6) | 0.9 | |
| Child’s characteristics | ||||
| Gender (n (%)) | ||||
| Male | 1445 (51.6) | 188 (53.1) | 0.6 | |
| Female | 1354 (48.4) | 166 (46.9) | ||
| Birth weight, kg (mean (SD)) | 3441 (547) | 3230 (676) | 0.005 | |
| Gestational age, weeks (median (IQR)) | 40.0 (39.1, 41.0) | 39.9 (38.9, 41.0) | 0.08 | |
Numbers do not always add to the full column totals due to missing data.
Binary outcomes were compared by χ2 test, categorical outcomes by a χ2 test for trend, and continuous variables using t-tests, after transformation where appropriate, or a Mann-Whitney U-test.