TABLE 1.
Characteristics of 991 mothers and children studied, compared with the rest of the Southampton Women's Survey cohort, born before the end of 2003
| Mother-child pairs studied |
Remaining mother-child pairs |
||||
| n | Value | n | Value | P value1 | |
| Mother | |||||
| Height, cm | 991 | 163.6 ± 6.42 | 852 | 162.8 ± 6.5 | 0.003 |
| BMI, kg/m2 | 991 | 24.3 (22.0–27.5)3 | 845 | 24.2 (22.0–28.1) | 0.62 |
| Age at child's birth, y | 991 | 30.4 ± 3.8 | 859 | 29.7 ± 3.8 | <0.001 |
| Serum vitamin D concentration,4 nmol/L | 991 | 61.0 (41.7–87.0) | 705 | 57.0 (40.2–82.4) | 0.07 |
| Educational attainment; qualifications >A-level,5 n (%) | 988 | 293 (29.7) | 859 | 228 (26.5) | 0.005 |
| Multiparous, n (%) | 991 | 524 (52.9) | 860 | 518 (60.2) | 0.001 |
| Smoked in pregnancy, n (%) | 991 | 140 (14.1) | 852 | 184 (21.6) | <0.001 |
| Pregnancy weight gain,6 n (%) | 991 | 703 | 0.68 | ||
| Inadequate | 216 (21.8) | 165 (23.5) | |||
| Adequate | 301 (30.4) | 204 (29.0) | |||
| Excessive | 474 (47.8) | 334 (47.5) | |||
| White ethnicity, n (%) | 991 | 953 (96.2) | 861 | 800 (92.9) | 0.002 |
| Child | |||||
| Gestation at birth, wk | 991 | 40.2 (39.3–41.0) | 859 | 40.1 (39.1–41.0) | 0.29 |
| Duration of breastfeeding, wk | 991 | 13.0 (1.0–30.4) | 758 | 6.0 (0.1–24.7) | <0.001 |
| BMI at 6 y, kg/m2 | 750 | 15.8 (14.9–16.9) | 124 | 15.5 (14.9–16.5) | 0.21 |
| Overweight/obese at 6 y,7 n (%) | 750 | 122 (16.3) | 124 | 18 (14.5) | 0.62 |
1
P values determined according to t test for normally distributed continuous variables, Mann-Whitney rank-sum tests for nonnormally distributed continuous variables, and χ2 tests for categorical variables.
2
Mean ± SD (all such values).
3
Median; IQR in parentheses (all such values).
4
Concentration determined in late pregnancy.
5
Educational qualification awarded at 18 y of age.
7
International Obesity Task Force categorization (17).