Skip to main content

Table 1 Demographic and medical characteristics of the sample

From: Prenatal risk factors and neonatal DNA methylation in very preterm infants

Sample characteristics Full sample
(N = 601)
Included
(N = 470)
Excluded
(N = 131)
p-value
Maternal characteristics*
Maternal education: < HS/GED 13% (79/598) 15% (68/468) 8.5% (11/130) 0.07
Low SES: Hollingshead = 5 9.9% (59/599) 8.5% (40/469) 15% (19/130) 0.04
Minority race or ethnicity± 58% (347/601) 55% (257/470) 69% (90/131) 0.004
No partner 25% (152/600) 26% (124/470) 22% (28/130) 0.26
Neonatal characteristics Full sample
(N = 704)
Included
(N = 542)
Excluded
(N = 162)
p-value
Infant gender = Male 56% (388/697) 55% (299/539) 56% (89/158) 0.85
Multiple gestation 26% (184/697) 27% (145/539) 25% (39/158) 0.58
Cesarean delivery 71% (495/696) 71% (382/539) 72% (113/157) 0.79
PMA at Birth (weeks) 27.0 ± 1.92 27.0 ± 1.92 27.0 ± 1.92 0.86
Birth weight (grams) 948.3 ± 280.6 951.1 ± 281.8 938.5 ± 277.0 0.62
Head circumference (cm) 24.5 ± 2.43 24.5 ± 2.48 24.4 ± 2.24 0.70
PMA at Discharge (weeks) 40.5 ± 5.43 40.3 ± 5.20 41.29 ± 6.12 0.05
Length of NICU stay (LOS days) 93.5 ± 41.9 91.7 ± 40.1 99.7 ± 47.4 0.05
Weight at discharge (grams) 3013 ± 905 3001 ± 861 3057 ± 1042 0.50
Severe retinopathy of prematurity 5.9% (41/697) 6.3% (34/539) 4.4% (7/158) 0.38
Necrotizing enterocolitis/sepsis 18% (128/697) 19% (103/539) 16% (25/158) 0.35
Chronic lung disease 51% (357/697) 51% (277/539) 51% (80/158) 0.87
Serious brain injury+ 13% (92/694) 13% (69/539) 15% (23/155) 0.51
  1. Means ± standard deviations (continuous) or percentage and frequencies (categorical) of demographic and medical characteristics. p-values refer to the comparison of included versus excluded individuals and were obtained from t-tests (continuous variables) and chi-squared tests (categorical variables)
  2. PMA, postmenstrual age; HS, high school; GED, General Equivalency Diploma; SES, socioeconomic status
  3. *All mothers with prenatal data were included in the latent class analysis. Included versus excluded in this Table refers to individuals with data for the epigenome-wide analysis
  4. ±Minority race or ethnicity was defined as any non-White race (e.g., Black, Asian) or ethnicity (e.g., Hispanic and/or Latino/a)
  5. +Serious brain injury included parenchymal echodensity, periventricular leukomalacia, or ventricular dilation diagnosed via cranial ultrasound