Table 1. Characteristics of mothers and offspring who had information on at least one set of outcome variables (wheeze, asthma, lung function or atopy) by maternal hypertensive disorders of pregnancy (total N=11,601).
| Mother and offspring characteristics | N | Normotensive | Gestational hypertension | Preeclampsia | Hypertension before pregnancy | P for difference | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N=9,268 |
N=1,675 |
N=238 |
N= 420 |
||||||||
| N | Mean (SD)/% | N | Mean (SD)/% | N | Mean (SD)/% | N | Mean (SD)/% | ||||
| Wheeze at 18 m | No | 7815 | 6218 | 72.3 | 1154 | 74.0 | 158 | 70.9 | 285 | 71.3 | |
| Yes | 2963 | 2378 | 27.7 | 405 | 26.0 | 65 | 29.1 | 115 | 28.8 | 0.47 | |
| Wheeze at 7 years | No | 7285 | 5861 | 89.6 | 1020 | 88.4 | 144 | 88.9 | 260 | 84.1 | |
| Yes | 879 | 678 | 10.4 | 134 | 11.6 | 18 | 11.1 | 49 | 15.9 | 0.02 | |
| Asthma | No | 6440 | 5185 | 79.9 | 902 | 79.1 | 120 | 74.5 | 233 | 75.6 | |
| Yes | 1655 | 1301 | 20.1 | 238 | 20.9 | 41 | 25.5 | 75 | 24.4 | 0.11 | |
| FEV1 SD score* | 6579 | 5238 | −0.01 (0.99) | 957 | 0.03 (1.03) | 138 | −0.09 (1.01) | 246 | 0.08 (0.98) | 0.27 | |
| FVC SD score* | 6676 | 5323 | −0.01 (0.99) | 964 | 0.06 (1.03) | 138 | −0.01 (1.01) | 251 | 0.03 (1.03) | 0.23 | |
| FEF25-75 SD score* | 6676 | 5323 | 0.00 (1.01) | 964 | −0.03 (0.99) | 138 | −0.18 (0.91) | 251 | 0.10 (1.02) | 0.04 | |
| Atopy | No | 5158 | 4114 | 79.5 | 743 | 79.1 | 107 | 81.1 | 194 | 77.9 | |
| Yes | 1339 | 1063 | 20.5 | 196 | 20.9 | 25 | 18.9 | 55 | 22.1 | 0.89 | |
| Sex | Male | 5980 | 4729 | 51.0 | 899 | 53.7 | 125 | 52.5 | 227 | 54.0 | |
| Female | 5621 | 4539 | 49.0 | 776 | 46.3 | 113 | 47.5 | 193 | 46.0 | 0.16 | |
| Multiple pregnancy | Singleton | 11297 | 9058 | 97.7 | 1597 | 95.3 | 224 | 94.1 | 418 | 99.5 | |
| Twin | 304 | 210 | 2.3 | 78 | 4.7 | 14 | 5.9 | 2 | 0.5 | <0.001 | |
| Maternal ethnicity | White | 10742 | 8562 | 97.6 | 1569 | 98.8 | 214 | 97.3 | 397 | 98.8 | |
| Non-white | 241 | 211 | 2.4 | 19 | 1.2 | 6 | 2.7 | 5 | 1.2 | 0.01 | |
| Maternal pre-pregnancy BMI (kg/m2) | 10312 | 8271 | 22.50 (3.33) | 1450 | 24.67 (4.69) | 208 | 24.64 (5.28) | 383 | 24.55 (4.91) | <0.001 | |
| Maternal age (years) | 11601 | 9268 | 28.50 (4.74) | 1675 | 28.31 (4.86) | 238 | 27.82 (5.45) | 420 | 28.91 (4.74) | 0.02 | |
| Parity | Nulliparous | 5009 | 3724 | 41.9 | 910 | 57.0 | 160 | 71.7 | 215 | 53.1 | |
| Multiparous | 6099 | 5160 | 58.1 | 686 | 43.0 | 63 | 28.3 | 190 | 46.9 | <0.001 | |
| Maternal smoking in pregnancy | None | 4902 | 3893 | 42.8 | 710 | 43.5 | 113 | 49.3 | 186 | 44.8 | |
| Passive | 3711 | 2884 | 31.7 | 603 | 36.9 | 79 | 34.5 | 145 | 34.9 | ||
| Mother 1-9 | 987 | 819 | 9.0 | 124 | 7.6 | 16 | 7.0 | 28 | 6.7 | ||
| Mother 10-19 | 1214 | 1027 | 11.3 | 132 | 8.1 | 16 | 7.0 | 39 | 9.4 | ||
| Mother 20+ | 553 | 467 | 5.1 | 64 | 3.9 | 5 | 2.2 | 17 | 4.1 | <0.001 | |
| Maternal education | Certificate of Secondary Education/vocational | 3003 | 2432 | 27.6 | 411 | 25.8 | 62 | 27.9 | 98 | 24.3 | |
| Ordinary level | 3906 | 3048 | 34.6 | 600 | 37.7 | 84 | 37.8 | 174 | 43.1 | ||
| Advanced level | 2601 | 2119 | 24.0 | 354 | 22.2 | 50 | 22.5 | 78 | 19.3 | ||
| Degree | 1520 | 1212 | 13.8 | 228 | 14.3 | 26 | 11.7 | 54 | 13.4 | 0.02 | |
| Maternal asthma | No | 9797 | 7851 | 89.1 | 1387 | 87.0 | 202 | 90.2 | 357 | 85.0 | |
| Yes | 1256 | 963 | 10.9 | 208 | 13.0 | 22 | 9.8 | 63 | 15.0 | 0.007 | |
| Gestational age (weeks)† | 11601 | 9268 | 40 (39, 41) | 1675 | 40 (39, 41) | 238 | 38 (36, 40) | 420 | 40 (38, 40) | <0.001 | |
| Birth weight (g) | 11460 | 9150 | 3421 (531) | 1658 | 3420 (587) | 234 | 2964 (849) | 418 | 3368 (619) | <0.001 | |
*
Lung function SD scores are standardised by age, sex and height
†
Median (inter-quartile range) is presented as this variable has a skewed distribution