Baseline characteristics and presence of signs of puberty by sex and age, separately for each birth cohort and pooled
| PIAMA (n=3963) | BAMSE (n=4089) | GINIplus (n=5991) | LISA (n=3094) | MAS (n=1314) | Total | |||||||
| Boys n/N (%) | Girls n/N (%) | Boys n/N (%) | Girls n/N (%) | Boys n/N (%) | Girls n/N (%) | Boys n/N (%) | Girls n/N (%) | Boys n/N (%) | Girls n/N (%) | Boys (%) | Girls (%) | |
| Sex | 2054/3963 (51.8) | 1909/3963 (48.2) | 2065/4089 (50.5) | 2024/4089 (49.5) | 2991/5830 (51.3) | 2839/5830 (49.7) | 1584/3094 (51.2) | 1510/3094 (48.8) | 684/1314 (52.1) | 630/1314 (48.0) | 51.3 | 48.8 |
| Parental allergy | 885/2025 (43.7) | 805/1889 (42.6) | 1001/2050 (48.8) | 976/2007 (48.6) | 1022/2340 (43.7) | 998/2214 (45.1) | 738/1470 (50.2) | 710/1384 (51.3) | 275/643 (42.8) | 300/601 (49.9) | 45.9 | 47.4 |
| Maternal smoking during pregnancy | 356/2037 (17.5) | 344/1889 (18.2) | 272/2065 (13.2) | 259/2023 (12.8) | 383/2474 (15.5) | 356/2327 (15.3) | 262/1524 (17.2) | 274/1450 (18.9) | 154/627 (24.6) | 154/584 (26.4) | 17.2 | 17.9 |
| Puberty at age 10 | – | – | – | – | 63/1593 (3.9) | 170/1372 (12.4) | 31/853 (3.6) | 85/702 (12.1) | 0/394 (0) | 58/326 (17.8) | 1.9 | 13.6 |
| Puberty at age 11 | 40/1316 (3.0) | 796/1295 (61.5) | – | – | – | – | – | – | 1/368 (0.3) | 147/299 (49.2) | 1.4 | 55.6 |
| Puberty at age 12 | – | – | 424/1390 (30.5) | 1184/1353 (87.5) | – | – | – | – | 21/361 (5.8) | 261/346 (75.4) | 16.3 | 82.0 |
| Puberty at age 13 | – | – | – | – | – | – | – | – | 117/373 (31.4) | 369/387 (95.4) | 31.4 | 95.4 |
| Puberty at age 14 | 1092/1264 (86.4) | 1363/1366 (99.8) | – | – | – | – | – | – | – | – | 86.4 | 99.8 |
| Puberty at age 15 | – | – | – | – | 1125/1268 (88.7) | 1274/1330 (95.8) | 683/741 (92.2) | 678/723 (93.8) | 289/315 (91.8) | 390/393 (99.2) | 90.8 | 96.6 |
| Puberty at age 16 | – | – | 1231/1318 (93.4) | 1594/1623 (98.2) | – | – | – | – | – | – | 93.4 | 98.2 |
BAMSE, Swedish abbreviation for Children, Allergy, Milieu, Stockholm, Epidemiology; GINIplus, German Infant Nutritional Intervention-Program; LISA, Lebensstil, Immunsystem, Allergien; MAS, Multizentrische Allergie Studie; n, number of participants per analysis; N, total number of participants at time of recruitment; PIAMA, Prevention and Incidence of Asthma and Mite Allergy.