Kisspeptin levels in women miscarrying longer than 21 days after the blood test were higher than the other miscarriage groups, but significantly lower than the group that did not miscarry (kisspeptin in picomoles per liter: 951 ± 716 miscarriage > 21 d, P < .001 vs no miscarriage) (Figure 3A). This evidence concerns the gene KISS1 and spontaneous abortion.