Respiratory distress syndrome of the newborn

Epidemiology and risk factors The incidence and severity of NRDS is inversely related to gestational age and birth weight. Whilst 60-80% of neonates born earlier than 28 weeks of gestation and 15-30% born at 32-36 weeks of gestation develop NRDS, it is rare in those more than 36 weeks of gestational age. The incidence of NRDS is 80% for infants weighing <750g at birth and 55% for infants weighing 750–1000g. Other risk factors include maternal diabetes, caesarean delivery, asphyxia, multiple births, precipitous delivery, cold stress and a maternal history of previous affected infants. In contrast, incidence of NRDS decreases with prolonged rupture of membranes, chronic pregnancy associated hypertension and antenatal corticosteroid prophylaxis.