Participating mother-child pairs (n=940) | Mother-child pairs with missing data (n=589) | p Value | |
---|---|---|---|
Maternal characteristics | |||
Age at child's birth, years (mean (SD)) | 30.3 (3.8) | 29.7 (3.8) | 0.007 |
Primiparous (n (%)) | |||
No | 494 (52.6) | 355 (60.3) | 0.003 |
Yes | 446 (47.5) | 234 (39.7) | |
Qualifications (n (%)) | |||
None | 15 (1.6) | 36 (6.1) | <0.001 |
GCSE D–G | 88 (9.4) | 67 (11.4) | |
GCSE A*–C | 278 (29.6) | 165 (28.1) | |
A level | 270 (28.8) | 175 (29.8) | |
HND | 66 (7.0) | 39 (6.6) | |
Degree | 222 (23.6) | 106 (18.0) | |
Parents’ social class (n (%)) | |||
I | 100 (10.8) | 52 (12.3) | 0.019 |
II | 454 (48.8) | 178 (42.3) | |
IIIN | 263 (28.5) | 112 (26.6) | |
IIIM | 72 (7.7) | 51 (12.1) | |
IV | 39 (4.2) | 20 (4.8) | |
V | 2 (0.2) | 8 (1.9) | |
Smoked in pregnancy (n (%)) | |||
No | 768 (84.9) | 431 (77.2) | <0.001 |
Yes | 137 (15.1) | 127 (22.8) | |
Maternal asthma (n (%)) | |||
No | 733 (78.7) | 442 (76.2) | 0.251 |
Yes | 198 (21.3) | 138 (23.8) | |
Maternal childhood eczema (n (%)) | |||
No | 758 (81.5) | 476 (82.1) | 0.783 |
Yes | 172 (18.5) | 104 (17.9) | |
Maternal rhinitis (n (%)) | |||
No | 539 (57.9) | 353 (60.9) | 0.254 |
Yes | 392 (42.1) | 227 (39.1) | |
Maternal atopy (n (%)) | |||
No | 438 (53.0) | 236 (57.0) | 0.185 |
Yes | 388 (47.0) | 178 (43.0) | |
Height, cm (mean (SD)) | 163.5 (6.6) | 162.7 (6.0) | 0.020 |
BMI, kg/m2 (median, (IQR)) | 24.3 (22.0–27.5) | 24.1 (21.8–27.4) | 0.657 |
Fat mass, kg (median, (IQR)) | 20.3 (16.3–25.9) | 19.5 (15.7–25.8) | 0.116 |
Child's characteristics | |||
Gender (n (%)) | |||
Male | 485 (51.6) | 313 (53.4) | 0.489 |
Female | 455 (48.4) | 273 (46.6) | |
Birth weight, kg (mean (SD)) | 3.440 (0.551) | 3.420 (0.580) | 0.615 |
Gestational age, weeks (median (IQR)) | 40.1 (39.0–41.0) | 40.0 (39.1–41.0) | 0.969 |
Mother smoked during child's infancy (n (%)) | |||
No | 768 (84.9) | 431 (77.2) | <0.001 |
Yes | 137 (15.1) | 125 (22.8) |
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 rank-sum test.