The frequency of samples with a blunted or stalled decidual response (PLA2G2A/DIO2 < 25th percentile) increased stepwise with each prior miscarriage, mirrored by a stepwise decrease in samples with a heightened decidual reaction (PLA2G2A/DIO2 > 75th percentile) (Fig. 4A and fig. Here, PLA2G2A is linked to spontaneous abortion.