Table 2.
Characteristics of children from Millennium Cohort Study included in this analysis. Values are numbers (percentages) unless stated otherwise
| Characteristics | Gestational age at birth (weeks) | P values comparing gestational age groups* | ||||
|---|---|---|---|---|---|---|
| <32 (n=225) | 32-33 (n=192) | 34-36 (n=1107) | 37-38 (n=3655) | 39-41 (n=12 540) | ||
| Mean (SD) birth weight (kg) | 1.3 (0.4) | 2.0 (0.4) | 2.6 (0.5) | 3.2 (0.5) | 3.5 (0.5) | <0.001 |
| Male sex | 123 (54.9) | 105 (59.7) | 587(53.5) | 1902 (51.5) | 6356 (50.6) | 0.13 |
| Ethnic group: | 0.032 | |||||
| White British | 176 (80.4) | 159 (88.4) | 927 (88.6) | 2986 (85.8) | 10 482 (87.8) | |
| Other† | 49 (19.6) | 33 (11.6) | 179 (11.4) | 669 (14.2) | 2053 (12.2) | |
| Multiple birth | 52 (21.4) | 42 (27.0) | 184 (17.5) | 179 (5.0) | 55 (0.4) | <0.001 |
| First born | 112 (50.1) | 91 (51) | 492 (44.9) | 1356 (37.3) | 5448 (43.4) | <0.001 |
| Mean (SD) length of neonatal hospital stay (weeks) | 9.2 (6.7) | 3.2 (1.7) | 1.4 (2.1) | 0.5 (0.7) | 0.4 (0.8) | <0.001 |
| Mean (SD) age at 3 year interview (years) | 3.1 (0.2) | 3.1 (0.2) | 3.1 (0.2) | 3.1 (0.2) | 3.1 (0.2) | 0.91 |
| Mean (SD) age at 5 year interview (years) | 5.1 (0.2) | 5.2 (0.2) | 5.2 (0.2) | 5.2 (0.2) | 5.2 (0.2) | <0.001 |
Means and percentages are weighted with sampling and non-response weights
*χ2 tests for categorical variables and F tests for continuous variables; calculated for weighted, clustered data.
†Mixed, Indian, black Caribbean/black African, Bangladeshi/Pakistani, other.