Placental epigenetic clocks: estimating gestational age using placental DNA methylation levels. 

Placental epigenetic clocks: estimating gestational age using placental DNA methylation levels. 
Lee Y, Choufani S, Weksberg R, Wilson SL, Yuan V, Burt A, Marsit C, Lu AT, Ritz B, Bohlin J, Gjessing HK. (2019) Aging.11(12):4238.