IGFBP1 and atrial fibrillation: The ProteinChip array-based immunoassay using SELDI showed that IGFBP-1 was largely in a full-length form in the AF of the patients with preterm labor without IAI, but significantly degraded in the AF pool of the patients who delivered preterm with IAI. This indicated a preferential production of IGFBP-1 fragments in the amniotic fluid of patients with IAI.