Table 1. Demographic Characteristics of the Study Populationa .
| Characteristic | No. (%) (N = 609) |
|---|---|
| Mother | |
| Age, mean (SD), y | 29.3 (4.6) |
| Pregestational body mass index, mean (SD)b | 24.6 (4.6) |
| Educational level | |
| Low | 75 (12.4) |
| Middle | 220 (36.3) |
| High | 314 (51.3) |
| Parity | |
| 1 | 336 (55.5) |
| 2 | 202 (33.0) |
| ≥3 | 71 (11.5) |
| Smoking status | |
| Never | 391 (64.2) |
| Before pregnancy | 152 (25.0) |
| During pregnancy | 66 (10.5) |
| Newborn | |
| Boy | 322 (52.4) |
| Race/ethnicity | |
| European | 536 (88.0) |
| Non-European | 73 (12.0) |
| Gestational age, mean (SD), wk | 39 (1.7) |
| Birth weight, mean (SD), g | 3414 (485) |
| Season of birth | |
| Winter | 156 (25.8) |
| Spring | 157 (25.8) |
| Summer | 144 (23.4) |
| Autumn | 152 (25.0) |
| White blood cell count, mean (SD), /μl | 15200 (4700) |
| Neutrophils, mean (SD), % | 53.2 (9.4) |
| H3K4me3, log, median (IQR), ng/mL | 10.3 (6.3-23.6) |
| H3K36, log, median (IQR), ng/mL | 8.9 (4.6-16.6) |
| Total histone H3, log, median (IQR), ng/mL | 32.3 (27.3-37.9) |
Abbreviations: IQR, interquartile range; H3K4me3, trimethylated H3 lysine 4; H3K36, H3 lysine 36.
SI conversion factor: To convert neutrophils to proportion of 1.0, multiply by 0.01; white blood cell count to ×109/L, multiply by 0.001.
a
Means are presented as geometric means (ie, 25th to 75th percentile).
b
Body mass index calculated as weight in kilograms divided by height in meters squared.