Table 1.
General study population characteristics
| Entire LINA cohort n (%), n = 629a | Analyzed sub-cohort n (%), n = 408 | χ 2 test b | |
|---|---|---|---|
| Gender of the child | 0.966 | ||
| Female | 302(48.0) | 197(48.3) | |
| Male | 327(52.0) | 211(51.7) | |
| Birth weight | 0.941 | ||
| ≤ 3000 g | 123(19.6) | 68(16.7) | |
| > 3000–3500 g | 242(38.5) | 157(38.5) | |
| > 3500–4000 g | 192(30.6) | 129(31.6) | |
| > 4000 g | 71(11.3) | 54(13.2) | |
| Gestational week at delivery | 0.834 | ||
| < 37 weeks | 25(4.0) | 10(2.5) | |
| 37–40 weeks | 389(62.0) | 255(62.5) | |
| > 40 weeks | 214(34.0) | 143(35.0) | |
| Smoking during pregnancy | 0.833 | ||
| Never | 534(84.9) | 358(87.7) | |
| Occasionally | 47(7.4) | 23(5.6) | |
| Daily | 48(7.6) | 27(6.6) | |
| Parental school educationc | 0.969 | ||
| Low | 16(2.5) | 8(2.0) | |
| Intermediate | 144(22.9) | 96(23.5) | |
| High | 469(74.6) | 304(74.5) | |
| Household members | 0.932 | ||
| 2 | 33(5.2) | 20(4.9) | |
| 3 | 365(58.0) | 257(63.0) | |
| > 4 | 203(32.3) | 129(31.6) | |
| Breastfeeding exclusive | 0.968 | ||
| 1–3 months | 112(17.8) | 69(16.9) | |
| 1–6 months | 190(30.2) | 121(29.7) | |
| 1–12 months | 254(40.4) | 172(42.2) | |
| Introduction to solid food | 0.897 | ||
| 1–3 months | 23(3.7) | 11(2.7) | |
| 4–6 months | 251(39.9) | 156(38.2) | |
| 7–12 months | 305(48.5) | 205(50.2) | |
| Urinary BPA concentration during pregnancy | 0.263d | ||
| Median [ng/mg creatinine] | 12.7 | 12.7 | |
| IQRe [ng/mg creatinine] | 7.5–16.0 | 7.6–15.9 | |
| BMI z score at year 1 | n = 564 | n = 366 | |
| Median | − 0.24 | − 0.16 | |
| IQR | − 0.90–0.35 | − 0.79-0.43 | |
| BMI z score at year 6 | n = 303 | n = 192 | |
| Median | − 0.02 | 0.05 | |
| IQR | − 0.67-0.50 | − 0.51-0.54 | |
an may be different from 629 due to missing data
bCalculated using the chi-squared test for cross relationship
cLow = 8 years of schooling (‘Hauptschulabschluss`); intermediate = 10 years of schooling (`Mittlere Reife`); high = 12 years of schooling or more (`(Fach-)hochschulreife’)
dp-value derived by Student’s t test between group means
eIQR: inter quartile range (25th to 75th percentile)