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Table 1 Demographic characteristics of discovery and replication cohorts

From: A cross-cohort analysis of autosomal DNA methylation sex differences in the term placenta

  Discovery Replication
Female (n = 177) Male (n = 164) p value* Female (n = 137) Male (n = 156) p value*
Gestational Age
 Weeks (mean (SD)) 39.0 (± 1.1) 39.1 (± 0.9) 0.53 39.6 (± 1.1) 39.7 (± 1.0) 0.28
Condition
 Healthy term 100 100 0.02 114 125 0.10
 SGA 37 45   9 4  
 LGA 40 19   13 24  
PlaNET Ancestry§
 Coordinate 1 (mean (SD)) 0.10 (± 0.25) 0.07 (± 0.23) 0.27 0.0009 (± 0. 0016) 0.0012 (± 0.0018) 0.000024
 Coordinate 2 (mean (SD)) 0.11 (± 0.26) 0.05 (± 0.14) 0.37 0.0038 (± 0.0270) 0.0032 (± 0.0103) 0.011
 Coordinate 3 (mean (SD)) 0.78 (± 0.36) 0.88 (± 0.27) 0.23 0.9951 (± 0.0279) 0.9956 (± 0.0111) 0.001
  1. SD refers to standard deviation; SGA and LGA refer to small (< 10th centile) and large (> 90th centile) birthweight for gestational age within each sex, as assigned by the original publications
  2. *p values represent male-female comparisons, from Wilcoxon rank-sum tests for continuous and Fisher’s exact test for categorical variables
  3. §PlaNET outputs of DNAme-based ethnicity/ancestry probability values range from 0 to 1 and sum to 1 for each sample. Coordinate 1 is associated with probability of African ancestry, coordinate 2 with East Asian ancestry, and coordinate 3 with European ancestry [40]