CXCL8 and spontaneous abortion: TLR9 GG and IL-8 CC interaction (z = −2.797, p=0.005), TLR9 GA and IL-8 CC interaction (z = −2.615, p=0.0089), TLR9 GG and IL-8 CT interaction (z = −2.612, p=0.0089), and TLR9 GG and IL-8 TT interaction (z = −3.318, p=0.0009) had a statistically significant negative effect on the risk of miscarriage.