Preterm Birth

Preterm birth is defined as a live birth before 37 completed weeks gestation. Preterm birth is further classified as: late preterm (34 to less than 37 weeks), moderately preterm (32 to less than 37 weeks) and very preterm (less than 32 weeks). These classifications are useful because they often correspond to clinical characteristics - increasing morbidities or illnesses with decreasing gestational age. Babies born too soon are often born too small. While the causes of preterm birth and low birthweight may be different in some cases, there is significant overlap within these populations of infants.