Table 1.
Characteristics of mothers and children included in the study compared with term live singleton births not in the study.
| Characteristic | In study |
||||
|---|---|---|---|---|---|
| Yes | No | p-value | |||
| n | Value | n | Value | ||
| Mother | |||||
| Primiparous, n (%) | 2557 | 1299 (51%) | 393 | 189 (48%) | 0.32 |
| Education, n (%) | 2552 | 392 | 0.04 | ||
| No academic qualification | 64 (3%) | 24 (6%) | |||
| GCSE grade D or below | 241 (9%) | 30 (8%) | |||
| GCSE grade C or above | 726 (28%) | 121 (31%) | |||
| A-level or equivalent | 781 (31%) | 117 (30%) | |||
| HNDs or equivalent | 168 (7%) | 20 (5%) | |||
| Degree | 572 (22%) | 80 (20%) | |||
| Pre-pregnancy BMI, median (1st & 3rd quartiles) | 2557 | 24.2 (21.9-27.3) | 369 | 24.0 (21.6-27.4) | 0.49 |
| Pre-pregnancy walking speed, n (%) | 2558 | 393 | 0.04 | ||
| Very slow | 7 (0.3%) | 4 (1%) | |||
| Stroll at an easy pace | 163 (6%) | 33 (8%) | |||
| Normal speed | 1039 (41%) | 167 (42%) | |||
| Fairly brisk | 1222 (48%) | 169 (43%) | |||
| Fast | 127 (5%) | 20 (5%) | |||
| Pre-pregnancy prudent diet score, mean (SD) | 2558 | 0.05 (0.96) | 393 | -0.06 (0.98) | 0.03 |
| Glycaemic Index 11-weeks, mean (SD) | 1852 | 59.5 (2.9) | 231 | 59.1 (2.8) | 0.03 |
| Glycaemic Index 34-weeks, mean (SD) | 2262 | 58.8 (2.8) | 280 | 58.6 (2.8) | 0.24 |
| Serum Vitamin D 11-weeks, nmol/l, mean (SD) | 1693 | 62.3 (25.4) | 201 | 62.9 (26.4) | 0.74 |
| Serum Vitamin D 34-weeks, nmol/l, median (1st & 3rd quartiles) | 1996 | 59.0 (41.0-84.5) | 243 | 55 (36.1-80.0) | 0.01 |
| GWG, kg, mean (SD) | 2216 | 12.1 (6.2) | 153 | 13.0 (6.2) | 0.08 |
| GWG according to IOM categories, n (%) | 2214 | 153 | 0.04 | ||
| Inadequate | 499 (23%) | 26 (17%) | |||
| Adequate | 657 (30%) | 41 (27%) | |||
| Excessive | 1058 (48%) | 86 (56%) | |||
| Age at child’s birth, years, mean (SD) | 2559 | 30.7 (3.8) | 392 | 30.4 (3.9) | 0.11 |
| Smoking at 6 months postpartum, n (%) | 2553 | 471 (18%) | 224 | 44 (20%) | 0.66 |
| Pre-pregnancy weight, kg, median (1st & 3rd quartiles) | 2559 | 64.8 (58.1-73.3) | 370 | 64.1 (57.6-72.8) | 0.43 |
| Postpartum weight 6 months, kg, median (1st & 3rd quartiles) | 2559 | 68.2 (60.4, 78.6) | 112 | 67.6 (59.6, 80.9) | 0.69 |
| Postpartum weight retention 6 months, kg, mean (SD) | 2559 | 3.5 (6.2) | 92 | 2.2 (5.6) | 0.04 |
| Child | |||||
| Gestational age at birth, weeks, mean (SD) | 2559 | 40.1 (1.2) | 392 | 40.0 (1.3) | 0.44 |
| Duration of breastfeeding, <6 months, n (%) | 2473 | 1811 (73%) | 233 | 160 (69%) | 0.14 |
Abbreviations: n – number; GCSE – General Certificate of Secondary Education (compulsory, ages 15-16 years); A-level – school leaving qualification (ages 17-18 years); HNDs – Higher National Diplomas; BMI – Body Mass Index; SD – standard deviation; GWG – Gestational Weight Gain; IOM – Institute of Medicine.