Underdeveloped lungs and prematurity

Particularly when an infant is born before 36 weeks' gestation, the premature infant's lungs are immature, and the body has limited muscle strength and energy for breathing. Therefore, the premature infant may not get enough oxygen, which can cause serious medical complications. It is common at birth for a premature infant to need oxygen therapy, a ventilator machine, and/or medicine to help with oxygen absorption and breathing.

Infants whose lungs have been quickly matured with corticosteroid treatment before birth (antenatal corticosteroids, given by injection to the mother) have significantly fewer medical complications than those who are not treated.¹

Infants with underdeveloped lungs often lack surfactant, a substance that coats the airways, preventing them from collapsing and sticking together. When premature lungs are treated with surfactant after birth, the infant's blood oxygen levels usually improve within minutes. Surfactant treatment reduces the risk and the severity of respiratory distress syndrome (RDS) in premature infants as well as the overall risk of death.²

Unlike corticosteroid treatment before birth, corticosteroid treatment after birth (postnatal) is losing favor in the medical community. Current research is focusing on how this medicine can be safely used to improve lung function without causing neurological deficits, gastrointestinal bleeding and damage, blood sugar problems, and high blood pressure. Postnatal corticosteroid treatment currently is only recommended for infants whose lungs are so impaired that they cannot be taken off ventilation.

Citations

1. Antenatal Corticosteroids Revisited: Repeat Courses. NIH Consensus Statement, vol. 17, no. 2 (2000 August 17–18). Available online: http://consensus.nih.gov/2000/2000AntenatalCorticosteroidsRevisted112html.htm.

2. Fraser J, et al. (2004). ABC of preterm birth: Respiratory complications of preterm birth. BMJ, 329(7472): 962–965.