In the subgroup analysis of patients with CI, the median AF levels of EN-RAGE, IL-8, lipocalin-2, MMP-9, S100A8/A9, and uPA were significantly higher in women with CI who had SPTB at < 32 weeks than in those who delivered at ≥ 32 weeks (Table 2). This evidence concerns the gene MMP9 and atrial fibrillation.