Table 4. Baseline profiles of the children in the Japan Environment and Children’s Study, 2011–2014.
Variables | Total | With participating fathers | ||||
Number of valid response |
n | Number of valid response |
n | |||
Number of live births | 100,148 | 51,539 | ||||
Singleton births, n % | 98,259 | 98.1 | 50,564 | 98.1 | ||
Gestational age at birth | 100,148 | 51,539 | ||||
Total, weeks, mean (SD) | 100,148 | 39.2 (1.7) | 51,539 | 39.2 (1.6) | ||
Preterm births (<37 weeks), n % | 5,599 | 5.6 | 2,644 | 5.1 | ||
Term births (37–41 weeks), n % | 94,322 | 94.2 | 48,763 | 94.6 | ||
Postterm births (≥42 weeks), n % | 227 | 0.2 | 132 | 0.3 | ||
Sex | 100,137 | 51,534 | ||||
Male, n % | 51,316 | 51.2 | 26,279 | 51.0 | ||
Female, n % | 48,821 | 48.8 | 25,255 | 49.0 | ||
Type of delivery | 99,884 | 51,413 | ||||
Vaginal, n % | 79,783 | 79.9 | 41,212 | 80.2 | ||
Caesarean, n % | 20,101 | 20.1 | 10,201 | 19.8 | ||
Birth weight, g | 100,071 | 51,509 | ||||
Total, mean (SD) | 100,071 | 3,008 (434) | 51,509 | 3,015 (425) | ||
Singleton births | 98,182 | 50,534 | ||||
Total, mean (SD) | 98,182 | 3,023 (420) | 50,534 | 3,030 (410) | ||
Male, mean (SD) | 50,312 | 3,065 (426) | 25,779 | 3,074 (415) | ||
Female, mean (SD) | 47,863 | 2,979 (408) | 24,751 | 2,984 (399) | ||
Low birth weight, <2,500 g, n % | 7,981 | 8.1 | 3,856 | 7.6 | ||
Birth height, cm | 99,785 | 51,336 | ||||
Total, mean (SD) | 99,785 | 48.8 (2.4) | 51,336 | 48.9 (2.3) | ||
Singleton births | 97,912 | 50,368 | ||||
Total, mean (SD) | 97,912 | 48.9 (2.3) | 50,368 | 49.0 (2.2) | ||
Male, mean (SD) | 50,166 | 49.2 (2.3) | 25,690 | 49.3 (2.2) | ||
Female, mean (SD) | 47,740 | 48.6 (2.3) | 24,675 | 48.7 (2.2) | ||
Birth head circumference, cm | 99,538 | 51,222 | ||||
Total, mean (SD) | 99,538 | 33.2 (1.5) | 51,222 | 33.2 (1.5) | ||
Singleton births | 97,692 | 50,265 | ||||
Total, mean (SD) | 97,692 | 33.2 (1.5) | 50,265 | 33.2 (1.5) | ||
Male, mean (SD) | 50,054 | 33.4 (1.5) | 25,635 | 33.4 (1.5) | ||
Female, mean (SD) | 47,633 | 33.0 (1.5) | 24,627 | 33.0 (1.4) | ||
Birth chest circumference, cm | 99,489 | 51,198 | ||||
Total, mean (SD) | 99,489 | 31.7 (1.9) | 51,198 | 31.7 (1.8) | ||
Singleton births | 97,653 | 50,245 | ||||
Total, mean (SD) | 97,653 | 31.8 (1.8) | 50,245 | 31.8 (1.8) | ||
Male, mean (SD) | 50,034 | 31.9 (1.9) | 25,625 | 31.9 (1.8) | ||
Female, mean (SD) | 47,614 | 31.6 (1.8) | 24,617 | 31.6 (1.8) |
SD, standard deviation.