--Disease Characteristics-- Threatened premature delivery at 24 to 30 weeks gestation, i.e.: Premature labor Premature rupture of membranes Elective premature delivery medically indicated Fetal lung maturity immature or unknown --Prior/Concurrent Therapy-- No more than 72 hours since any initial corticosteroids --Patient Characteristics-- The following complications exclude: Fetal distress Amnionitis Severe maternal bleeding uncontrolled with transfusion or volume replacement Fetal or maternal heart disease Significant fetal blood loss Maternal blood pressure 140/90 mm Hg or higher with or without treatment Maternal hyperthyroidism Maternal hyperprolactinemic condition Significant fetal anomaly Multiple gestation with demise of 1 or more fetuses Nonimmune hydrops No participation in other clinical research projects