Table 1.
Participant characteristics in NFBC1966, NFBC1986, ABC and ALSPAC
| NFBC1966 (N = 3321) | NFBC1986 (N = 4764) | ABC (N = 1920) | ALSPAC (N = 6517) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean (SD) | N (%) | P | Mean (SD) | N (%) | Mean (SD) | N (%) | P | Mean (SD) | N (%) | P | |
| Birth weight [g] | 3533 (480) | 3321 (100) | <0.01 | 3627 (470) | 4764 (98) | 3551 (518) | 1695 (88) | <0.01 | 3491 (467) | 6461 (99) | <0.01 |
| Maternal height [cm] | 160 (5.3) | 3169 (95) | <0.01 | 163 (5.4) | 4723 (99) | 168 (5.9) | 1756 (91) | <0.01 | 164 (6.6) | 6202 (95) | <0.01 |
| Maternal BMI [kg/m2] | 23.1 (3.2) | 3056 (92) | <0.01 | 22.3 (3.4) | 4660 (98) | 21.7 (3.4) | 1730 (90) | <0.01 | 22.9 (3.7) | 5903 (91) | <0.01 |
| Maternal age [years] | 27.9 (6.5) | 3315 (100) | <0.01 | 28.5 (5.4) | 4764 (100) | 30.1 (4.4)) | 1754 (91) | <0.01 | 29.1 (4.6) | 6516 (100) | <0.01 |
| n (%) | N (%) | P | n (%) | N (%) | n (%) | N (%) | P | n (%) | N (%) | P | |
| Offspring boy | 1628 (49) | 3321 (100) | 0,83 | 2347 (49) | 4764 (100) | 986 (51) | 1920 (100) | 0,12 | 3259 (50) | 6517 (100) | 0,44 |
| Maternal smoking | 421 (13) | 3254 (98) | <0.01 | 829 (18) | 4664 (98) | 435 (29) | 1509 (79) | <0.01 | 1630 (26) | 6386 (98) | <0.01 |
| Maternal cohabiting | 3215 (97) | 3317 (100) | 0,01 | 4559 (96) | 4755 (100) | 1479 (96) | 1546 (81) | 0,72 | 5982 (95) | 6321 (97) | <0.01 |
| Maternal education | 487 (14.9) | 3273 (99) | <0.01 | 1278 (30) | 4199 (88) | 1224 (66) | 1868 (97) | <0.01 | 4890 (77.7) | 6290 (97) | <0.01 |
| Offspring first born | 1138 (34) | 3315 (100) | 0,24 | 1570 (33) | 4748 (100) | 787 (50) | 1570 (82) | <0.01 | 2933 (47) | 6293 (97) | <0.01 |
N (%) refers to number of individuals in the study population with information on the variable and the percentage this constitutes of the given cohort.
ABC, the Aarhus Birth Cohort [{measured a median of 10 times (5–95% range: 6–13}]; ALSPAC, the Avon Longitudinal Study of Parents and Children [{measured a median of 9 times (5–95% range: 4–15}]; BMI, body mass index; NFBC1966, the Northern Finland Birth Cohort born 1966 [{measured a median of 14 times (5–95% range: 7–23}]; NFBC1986, the Northern Finland Birth Cohort born 1986 [{measured a median of 12 times (5–95% range: 8–17}]; SD, standard deviation.