Maternal clinical characteristics of singleton pregnancies recorded at booking visit
| Total | Underweight | Normal weight | Overweight | Obese I | Obese II | Obese III | ANOVA χ2 | ||
| Pregnancies | n | 152 961 | 3147 | 74 041 | 45 098 | 19 097 | 7861 | 3717 | |
| % | – | 2.06 | 48.41 | 29.48 | 12.48 | 5.14 | 2.43 | ||
| Folic acid | |||||||||
| Yes | 144 506 (94.5) | 2931 (93.1) | 69 823 (94.3) | 42 667 (94.6) | 18 088 (94.7) | 7471 (95.0) | 3526 (94.9) | p<0.001 | |
| Not recorded | 8455 (5.5) | 216 (6.9) | 4218 (5.7) | 2431 (5.4) | 1009 (5.3) | 390 (5.0) | 191 (5.1) | ||
| Systolic blood pressure‡ (mean±SD, mm Hg) | 113.00±12.0 | 106.10±11.0 | 109.99±11.0 | 113.92±11.4 | 118.00±11.8 | 121.19±12.1 | 124.48±12.5 | p<0.001 | |
| Diastolic blood pressure‡ (mean±SD, mm Hg) | 68.0±8.9 | 63.84±7.9 | 65.98±8.1 | 68.51±8.9 | 71.38±8.7 | 73.76±8.8 | 75.87±9.0 | p<0.001 | |
| History of hypertension‡ | 5077 (3.3) | 20 (0.64) | 1331 (1.80) | 1472 (3.26) | 1108 (5.80) | 684 (8.70) | 462 (12.43) | p<0.001 | |
| History of type 1 diabetes‡ | † | † | 203 (0.27) | 212 (0.47) | 111 (0.58) | 34 (0.43) | 17 (0.46) | p<0.001 | |
| History of type 2 diabetes‡ | † | † | 29 (0.04) | 50 (0.11) | 57 (0.30) | 52 (0.66) | 48 (1.29) | p<0.001 | |
| History of TIA/stroke‡ | † | † | 68 (0.09) | 32 (0.07) | 25 (0.13) | 10 (0.13) | † | p=0.078 | |
| History of psychiatric illness‡ | 9147 (6.0) | 239 (7.59) | 3732 (5.04) | 2618 (5.81) | 1385 (7.25) | 736 (9.36) | 437 (11.76) | p<0.001 | |
Underweight <18.5 kg/m2; normal weight 18.5–24.99 kg/m2; overweight 25.00–29.99 kg/m2; obese I 30.00–34.99 kg/m2; obese II 35.00–39.99 kg/m2; obese III ≥40 kg/m2
†, Suppressed due to small numbers (<10) NB whole group frequencies are also suppressed in the case where subgroups have small counts; ANOVA, analysis of variance; TIA, Transient Ischaemic Attack.