Risk factors and postnatal biomarkers for acute placental inflammatory lesions and intrauterine infections in preterm infants.

• The value of serum sialic acids of preterm infants within 1-hour afterbirth may be one of the rapid postnatal biomarkers for evaluating the severity of intra-amniotic infection. • The closer the placental lesions are to the fetus, the higher the content of serum sialic acid is.