Objectives: The purpose of the study was to determine whether the obstetrical judgment of viability makes a difference to fetal and neonatal survival of extremely low birthweight infants (500-749 g).
Methods: We assessed the effect of the antenatal judgment of viability in a group of 66 infants born weighing from 500 to 749 g. These infants were alive at maternal hospital admission and were subsequently live-born or stillborn between January 1, 1984, and December 31, 1985. We related the antepartum assessment of viability and other factors recorded in the medical record to fetal survival and to postneonatal survival to hospital discharge.
Results: The obstetrical judgement of viability was strongly associated with outcome. After birthweight and gestational age were controlled, fetuses considered viable were 18 times more likely to survive (95% confidence interval = 2, 175) than those considered nonviable.
Conclusions: The effects of obstetrical practices on perinatal mortality must be taken into consideration in estimating the survival potential of very small fetuses and in evaluating the relationship between survival and disability.