Family members should also be provided with an overview of the potential complications of prolonged intensive care. Finally, they should be informed of the range of survival rates and of the rates of long-term disabilities that can be expected. These rates do not represent ultimate survival rates, as deaths may occur in the postneonatal period. It is difficult to counsel parents regarding long-term disabilities because outcomes are only now being reported for neonates born since the use of surfactant became common and who have survived to school age. Recent experience suggests that almost half of the surviving children who weigh less than 750 g at birth experience moderate or severe disability, including blindness and cerebral palsy, and require special education.
Many infants have more than one disability.
The estimation of gestational age before premature delivery forms the main basis for subsequent decision-making. Clinical assessment to determine gestational age is usually appropriate for the woman with regular menstrual cycles and a known last menstrual period that was confirmed by an early examination. Fetal measurements derived through the use of ultrasonography at the time of anticipated delivery should not be used to alter estimated gestational age unless there is a discrepancy of 2 weeks or more between the age derived by menstrual dating and the age derived sonographically or the woman is uncertain about the date of her last menstrual period. Ultrasonography may provide useful information regarding the presence or absence of fetal malformations that may alter the prognosis. Thus, an infant estimated to weigh 600 g may have an actual birth weight of less than 500 g or more than 700 g.