Phenobarbital Administration in Pregnancies Undergoing IUT Due to Rh Alloimmunization: A Single-Blinded Randomized Trial

Background: Red blood cell (RBC) alloimmunization and the ensuing hemolysis in hemolytic disease of the fetus and newborn (HDFN) result in significant prenatal and postnatal mortality and morbidity through severe fetal anemia and hyperbilirubinemia. Phenobarbital induces hepatic enzymes involved in bilirubin metabolism. This study aimed to assess the effect of maternal phenobarbital administration on reducing postnatal blood exchange transfusion and phototherapy. Methods: This parallel-group, single-blind, randomized clinical trial with a control group was performed on ۷۵ pregnant women undergoing intrauterine transfusion (IUT) for Rh alloimmunization. The trial is described as single-blinded (only the assessing pediatrician was blinded), and the control group received no placebo. Participants were randomly divided into intervention and control groups using the random allocation rule. The intervention group received ۳۰ mg of phenobarbital three times daily from ten days prior to the estimated due date until actual delivery. The women were followed up until delivery to assess pregnancy outcomes, including incidence of icterus or need for postnatal phototherapy or exchange transfusion. Results: The first total bilirubin in the intervention group was significantly (p < ۰.۰۰۱) lower than that in the control group (۴.۹۹ ± ۱.۳۹ vs. ۱۰.۵۲ ± ۵.۸۸). The study outcomes, including icterus (p < ۰.۰۰۱), need for phototherapy (p < ۰.۰۰۱), and exchange transfusion (p < ۰.۰۰۱), were significantly lower in the intervention group. Logistic regression analysis showed that phenobarbital prescription in the intervention group significantly (p < ۰.۰۰۱) decreased the need for exchange transfusion by ۹۴%. Conclusion: This trial indicates the efficacy of late-gestation maternal phenobarbital (as a safe and low-cost intervention) in reducing postnatal hyperbilirubinemia and the need for phototherapy and exchange transfusion in neonates with severe Rh alloimmunization treated by IUT.

کلیدواژه ها:

Exchange transfusion ، Hemolytic disease of the fetus and newborn (HDFN) ، Hyperbilirubinemia ، Phenobarbital ، Phototherapy