Preterm birth is a syndrome with many causes and phenotypes. We propose a classification
that is based on clinical phenotypes that are defined by≥ 1 characteristics of the mother, the
fetus, the placenta, the signs of parturition, and the pathway to delivery. Risk factors and
mode of delivery are not included. There are 5 components in a preterm birth phenotype:(1)
maternal conditions that are present before presentation for delivery,(2) fetal conditions that
are present before presentation for delivery,(3) placental pathologic conditions,(4) signs of …