Predictive factors of perinatal mortality in transfused fetuses due to maternal alloimmunization: what really matters?

Introduction: Alloimmunization is the main cause of fetal anemia. There are not many consistent analyses associating antenatal parameters to perinatal mortality in transfused fetuses due to maternal alloimmunization. The study aimed to determine the prognostic variables related to perinatal death. Material and Methods: A cohort study analyzed 128 fetuses treated with intrauterine transfusion (IUT), until the early neonatal period. Perinatal mortality was associated with prognostic conditions related to prematurity, severity of fetal anemia and IUT procedure by univariated logistic regression. Multiple logistic regression was used to compute the odds ratio (OR) for adjusting the hemoglobin deficit at the last IUT, gestational age at birth, complications of IUT, antenatal corticosteroid and hydrops. Results: Perinatal mortality rate found in this study was 18.1%. The hemoglobin deficit at the last IUT (OR: 1.26, 95% CI: 1.04-1.53), gestational age at birth (OR: 0.53, 95% CI: 0.38-0.74) and the presence of transfusional complications (OR: 5.43, 95% CI: 142-20.76) were significant in predicting fetal death. Conclusion: Perinatal mortality prediction in transfused fetuses is not associated only to severity of anemia, but also to the risks of IUT and prematurity.