Antenatal phenobarbital for the prevention of neonatal intracerebral hemorrhage.

Forty-six pregnant women less than 35 weeks of gestation were enrolled in a prospective randomized controlled study evaluating the effects of antenatal phenobarbital on neonatal intracerebral hemorrhage. The women were randomly assigned to control (n = 22) or treatment (n = 24) groups; the treatment group received 500 mg of phenobarbital intravenously. The time interval between the dose of phenobarbital and delivery was 5.5 +/- 4.8 hours (mean +/- SD). The infants in the control group (n = 23) and those in the phenobarbital-treated group (n = 25) were comparable regarding birth weight, gestational age, and other obstetric and neonatal risk factors associated with intracerebral hemorrhage. The incidence of intracerebral hemorrhage was 56.5% (13 of 23 infants) in the control group and 32% (eight of 25 infants) in the phenobarbital-treated group (p = 0.08). Moderate or severe hemorrhage was diagnosed in six of 13 control infants and in none of the phenobarbital-treated infants (p less than 0.01). The mortality rate was significantly lower in the phenobarbital-treated group (two of 25 infants) than in the control group (eight of 23 infants; p less than 0.05). Our study suggests that antenatal phenobarbital administration results in a decrease in mortality and in the severity of intracerebral hemorrhage in the preterm neonate.