Characteristics of the study population: newborns from the cities of Munich (Germany) and Leipzig (Germany) with complete information on cord blood immunoglobulin (Ig) E and biocontaminants in mattress dust in 1998–1999
| Prevalence % | Frequency n/N | |
| Munich | 56.1 | 747/1332 |
| Leipzig | 43.9 | 585/1332 |
| Males | 51.9 | 691/1332 |
| Parental education# | ||
| Low | 23.4 | 308/1316 |
| Medium | 18.5 | 244/1316 |
| High | 58.1 | 764/1316 |
| Parental atopy¶ | ||
| None | 47.7 | 633/1328 |
| Mother | 35.7 | 474/1328 |
| Father | 32.6 | 409/1256 |
| Mother or father | 38.2 | 507/1328 |
| Both | 14.2 | 188/1328 |
| Smoking | ||
| During pregnancy+ | 10.4 | 131/1263 |
| ETS at home+ | 17.7 | 224/1267 |
| Cord blood | ||
| ≥0.35 kU·L−1ƒ | 32.1 | 427/1332 |
| ≥0.45 kU·L−1 (4th quartile) | 24.8 | 330/1332 |
| ≥0.90 kU·L−1 | 13.9 | 185/1332 |
n: available data
N: total sample size
ETS: environmental tobacco smoke
#: low <10 grades, medium 10 grades, high >10 grades
¶: life-time prevalence of asthma, hay fever or atopic eczema
+: during second or third trimester
ƒ: limit of detection