Associations of circulating folate, vitamin B12 and homocysteine concentrations in early pregnancy and cord blood with epigenetic gestational age: the Generation R Study

Table 1 Maternal and child characteristics based on non-imputed data (n = 1346)

Maternal characteristics
Age, year	31.4 (4.2)
Educational level
No or primary	26 (2.0)
Secondary	439 (33.1)
Higher	826 (65.0)
Parity
Nulliparous	817 (60.7)
Multiparous	528 (39.3)
Pre-pregnancy body mass index, kg/m²	22.3 (18.4, 33.7)
Smoking
Non-smoker or smoked until pregnancy was known	1059 (85.7)
Smoked throughout pregnancy	176 (14.3)
Gestational age at blood sampling, week	12.8 (9.9, 16.9)
Newborn characteristics
Gestational age at birth, week	40.3 (36.7, 42.3)
DNA methylation gestational age (Bohlin), week	39.4 (37.0, 40.8)
Raw gestational age acceleration (Bohlin), week	− 0.9 (− 2.7, 0.9)
DNA methylation gestational age (Knight), week	36.3 (32.4, 39.1)
Raw gestational age acceleration (Knight), week	− 3.7 (− 7.4, − 1.1)
Sex
Boy	684 (50.8)
Girl	662 (49.2)
Birth weight, gram	3546 (510)

Values are mean (SD) or median (95% range) for continuous variables and numbers (%) for categorical variables. Missing data: DNA methylation gestational age and gestational age acceleration estimated by Bohlin’s epigenetic clock (n = 11), highest completed education (n = 19), parity (n = 1), pre-pregnancy BMI (n = 199), smoking (n = 111), gestational age at blood sampling in pregnancy (n = 223), birth weight (n = 1)

ISSN: 1868-7083