CD19 and spontaneous abortion: Compared to the control group, body mass index, Protein S, CD19 + CD3-B lymphocytes, and 25-OH-VitD were significantly lower in the spontaneous abortion group during early pregnancy (P = .001; P = .004; P = .009; P = .001), blood glucose (fasting) and TNF-α significantly increased (P = .001; P = .046).