Table 1.
Characteristics of the 257 715 White UK Biobank participants from singleton pregnancies with birthweight data available, where birthweight is ≥1000 g. The mean birthweight has also been summarized for each characteristic investigated. P-values represent the difference in birthweight for different characteristics. Note the multiple births data include 7185 additional individuals reported as part of a multiple birth
| Number (%) | Mean birthweight g (standard deviation) | P | ||
|---|---|---|---|---|
| Mean age at recruitment, years (SD) | 55.33 (8.09) | 3358 (632) | ||
| Year of birth | 1934–1943 | 37 176 (14.43) | 3344 (711) | <0.0001 |
| 1944–1953 | 104 400 (40.51) | 3362 (646) | ||
| 1954–1963 | 83 671 (32.47) | 3353 (596) | ||
| 1964–1971 | 32 468 (12.60) | 3371 (577) | ||
| Sex | Male | 100 439 (38.97) | 3484 (650) | <0.0001 |
| Female | 157 276 (61.03) | 3277 (607) | ||
| Ethnicity | White | 234 (0.09) | 3402 (747) | <0.0001 |
| White British | 242 987 (94.29) | 3356 (630) | ||
| White Irish | 5995 (2.33) | 3411 (692) | ||
| White other | 8499 (3.30) | 3362 (652) | ||
| Multiple births | Yes | 7185 (2.71) | 2489 (690) | <0.0001 |
| No | 257 715 (97.21) | 3358 (632) | ||
| Maternal smoking | Yes | 68 332 (26.51) | 3288 (659) | <0.0001 |
| No | 162 889 (63.21) | 3387 (614) | ||
| Unknown | 26 468 (10.27) | 3355 (659) | ||
| Prefer not to answer | 16 (0.01) | 3356 (637) | ||
| Townsend deprivation index | −6.26−(–)3.64 | 68 671 (26.65) | 3366 (614) | <0.0001 |
| −3.64−(–)2.14 | 66 961 (25.98) | 3361 (625) | ||
| −2.13–0.55 | 65 004 (25.22) | 3356 (632) | ||
| 0.55–11.00 | 56 739 (22.02) | 3345 (663) | ||
| Missing | 340 (0.13) | 3398 (615) | ||
| Participant type 2 diabetes | No | 246 574 (95.79) | 3361 (628) | <0.0001 |
| Yes | 6576 (2.55) | 3274 (734) | ||
| Unknown | 4269 (1.66) | 3303 (696) | ||
| Parental diabetes | Neither | 193 741 (75.20) | 3358 (622) | <0.0001 |
| Father only | 20 057 (7.78) | 3311 (602) | ||
| Mother only | 19 478 (7.56) | 3415 (675) | ||
| Both | 2754 (1.07) | 3370 (662) | ||
| Missing | 21 685 (8.41) | 3348 (696) |