Antenatal maternal administration of phenobarbital for the prevention of exchange transfusion in neonates with hemolytic disease of the fetus and newborn.

OBJECTIVE: Hemolytic disease of the fetus and newborn infant (HDFN) can be associated with bilirubin encephalopathy, which is usually averted through neonatal exchange transfusions (EXT). However, EXT can be associated with significant procedure-related morbidity. We hypothesized that maternal oral administration of phenobarbital (PB) to women with HDFN would reduce the rate of EXT.

STUDY DESIGN: Cases of HDFN from January 1985 to June 2003 were reviewed. All patients who underwent serial intrauterine transfusions (IUTs) for red cell alloimmunization were included. Patients were offered oral phenobarbital (30 mg 3 times a day) after their last IUT in an effort to enhance fetal hepatic maturity. Variables studied included gestational age and hemoglobin multiples of the median at first transfusion and delivery, peak neonatal bilirubin, need for exchange transfusion, and maternal PB administration. Multivariate regression analysis was applied to determine relative risks and 95% CIs.

RESULTS: Seventy-one patients met study criteria; 29% of the neonates underwent EXT. The use of antenatal PB was associated with a decreased incidence of EXT, 9% versus 52% ( P < .01). After controlling for confounding variables, the relative risk for EXT after antenatal PB administration was 0.23 (95% CI: 0.06-0.76).

CONCLUSION: Maternal administration of PB reduces the need for neonatal EXTs in HDFN.