Table 1.
Distributions of maternal characteristics during pregnancy by ethnicity.
| Maternal Characteristics | Category | All (n = 8774) | White European (n = 4072) | South Asian (n = 4702) | Diff in Means or OR (95% CI) * |
|---|---|---|---|---|---|
| Age, years | 27.3 ± 5.6 | 26.7 ± 6.0 | 27.8 ± 5.2 | 1.1 (0.8, 1.3) | |
| Height (cm) | 161.7 ± (6.4) | 164.2 ± 6.2 | 159.5 ± 5.8 | 4.7 (4.5, 5.0) | |
| Missing (%) | 172 (2.0) | 57 (1.4) | 115 (2.4) | - | |
| BMI (kg/m2) | 26.1 ± 5.7 | 26.7 (6.0) | 25.6 ± 5.4 | 1.1 (0.9, 1.4) | |
| Missing (%) | 413 (4.7) | 183 (4.5) | 230 (4.9) | - | |
| TST (mm) | 25.4 ± 7.1 | 25.7 ± 7.2 | 24.6 (6.9) | 1.1 (0.6, 1.6) | |
| Missing (%) a | 5671 (64.6) | 1891 (46.4) | 3780 (80.4) | - | |
| Education | Below A-level | 5151 (58.7) | 2462 (60.5) | 2689 (57.2) | Ref |
| A-level or above | 3446 (39.3) | 1523 (37.4) | 1923 (40.9) | 1.2 (1.1, 1.3) | |
| Unknown/Missing (%) | 177 (2.0) | 87 (2.1) | 90 (1.9) | - | |
| HDP | Normotensive | 7902 (90.1) | 3533 (86.8) | 4369 (92.9) | Ref |
| PE | 224 (2.6) | 118 (2.9) | 106 (2.3) | 0.7 (0.6, 0.9) | |
| GHT | 634 (7.2) | 417 (10.2) | 217 (4.6) | 0.4 (0.3, 0.5) | |
| Missing (%) | 14 (0.2) | 4 (0.1) | 10 (0.2) | - | |
| Gestational Diabetes | Yes | 734 (8.4) | 209 (5.1) | 525 (11.2) | 2.3 (1.9, 2.7) |
| Parity | Median (IQR) | 1 (0–2) | 1 (0–1) | 1 (0–2) | - |
| Nulliparous | 3433 (39.1) | 1938 (47.6) | 1495 (31.8) | Ref | |
| Multiparous | 5037 (57.4) | 2000 (49.1) | 3037 (64.6) | 2.0 (1.8, 2.1) | |
| Missing (%) | 304 (3.5) | 134 (3.3) | 170 (3.6) | - | |
| Gest Age at Blood Sampling (weeks) | 26.3 (2.0) | 26.2 (1.9) | 26.3 (2.0) | 0.0 (−0.1, 0.0) |
Diff, difference; OR, odds ratio; CI, confidence interval; BMI, body mass index; TST, tricep skinfold thickness; HDP, hypertensive disorders of pregnancy; PE, pre-eclampsia; GHT, gestational hypertension; Gest, gestational; Ref, reference range. Data are means ± SD or n (%) unless stated. For characteristics with no “missing” category, data were 100% complete. a A large proportion of women had missing data for tricep skinfold thickness, and this was more marked for South Asian women. Further analyses (Tables S1–S3, Supplementary Materials) show differences in characteristics between those women who did and did not have skinfold thickness measurements. * Difference in mean calculated for continuous variables and odds ratio calculated for categorical variables; an odds ratio >1 indicates a higher exposure rate in South Asian women.