ACOG Practice Bulletin: Clinical Management Guidelines for Obstetrcian-Gynecologists: Number 38, September 2002. Perinatal care at the threshold of viability.

The survival rate for extremely preterm or extremely low-birth-weight (LBW) newborns born at the threshold of viability (25 or fewer completed weeks of gestation) improved in the early 1990s, largely as the result of a greater use of assisted ventilation in the delivery room and surfactant therapy. Increased use of antenatal and neonatal corticosteroids also may have influenced survival rates. However, this improvement in survival has not been associated with an equal improvement in morbidity. The incidence of chronic lung disease, sepsis, and poor growth remains high and may even have increased. There is concern that the treatment of extremely preterm and extremely LBW newborns may result in unforeseen effects into adulthood, and that the neurodevelopmental outcome and cognitive function of extremely preterm and extremely LBW infants may be suboptimal. The purpose of this document is to describe the potential consequences of extremely preterm birth and to provide clinical management guidelines based on the best available data.