Preterm birth refers to a delivery that occurs before 370/7ths weeks of gestation. It may or may not be preceded by preterm labor. Although term pregnancy has been defined as 370/7ths to 416/7ths weeks of gestation, the period 370/7ths to 386/7ths weeks should be considered ‘early term’ because neonates born in this gestational age range have higher neonatal morbidity and mortality than infants born at ‘full term’ from 390/7ths to 406/7ths weeks [1,2].
Classification — Subtypes of preterm birth are variably defined.
By gestational age :
●Moderate preterm: 32 to <37 weeks
●Late preterm: 340/7ths to 366/7ths weeks