The evidence in this review does not support the use of prophylactic maternal phenobarbital administration to prevent PVH in preterm infants or to protect them from neurological disability in childhood. Phenobarbital administration may lead to maternal sedation. If any future trials are carried out, they should measure neurodevelopmental status at follow up.
Use of prenatal phenobarbital in the prevention of subependymal/intraventricular hemorrhage in premature infants.
Subependymal/intraventricular hemorrhage (SE/IVH) is a frequent cause of disability and mortality.
                This is a prospective, randomized, double-blind study which included 100 pregnant Mexican women who need to interrupt their pregnancy within 28-32 weeks of gestation. One group was given a single dose of intravenous (IV) phenobarbital 10 micrograms/kg (phenobarbital group, n = 50), and the other was provided with diluted distilled water (control group). Measurements of phenobarbital serum concentrations were taken by both mother and newborn, and head sonograms were applied during the first 24 hours, at the 3rd and 7th days of life.
                The sample was made up of 42 newborns in the phenobarbital group, and 46 in the control group; the newborns had phenobarbital levels of 11.5 5.7 g/microliter at birth, and of 9.5 +/- 5.9 g/microliter 24 hours later. SE/IVH was found in 12 patients from the phenobarbital group and in 29 from the control group (p < 0.005), the first group were 11 mild SE/IVH (2 grade I, and 9 grade II), and 26 in the control group (4 grade I, and 22 grade II), p < 0.005. Severe hemorrhages were similar between groups. A larger frequency of SE/IVH was found in the newborn group which received mechanical ventilation (p = 0.0008).
                Prenatal phenobarbital can reduce the SE/IVH frequency in premature infants younger than 32 weeks at birth. Its main effect could be shown in patients with mechanical ventilation.