This large randomized trial tested whether phenobarbital given to a pregnant woman about to deliver a premature infant would prevent brain injuries in their newborns. Women with 24 to 32 week fetuses who were in preterm labor and were expected to deliver within 24 hrs were randomized to phenobarbital or usual care. They were treated until they deliver or the fetus reaches 33 wks gestation. Babies were followed until discharge and evaluated at 18-22 mos corrected age for neurodevelopmental outcome.