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.

Combined use of the cardiofemoral index and middle cerebral artery Doppler velocimetry for the prediction of fetal anemia.

OBJECTIVE: To assess the accuracy of the combined use of the cardiofemoral index (CFI) and the middle cerebral artery peak systolic velocity (MCA-PSV), converted to multiples of the median (MoM), as noninvasive means to detect severe fetal anemia. METHOD: We measured CFI and MCA-PSV MoM in 37 fetuses just before their first (n=37), second (n=22), and third (n=14) cordocenteses and transfusions. Then, using 2 different criteria for severe fetal anemia detection (Hb deficit ≥7 g/dL and hemoglobin level ≤0.55 of MoM), we assessed their hemoglobin status during cordocentesis and the accuracy of CFI and MCA-PVS was determined. RESULTS: At the first cordocentesis the mean hemoglobin level was 8.5±3.6 g/dL and 15 fetuses (40.5%) had hydrops. In a total of 81 fetal evaluations, 58 (71.6%) of the CFIs and 34 (42.0%) of the MCA-PSV MoM measurements were abnormal. The result of one of these tests was abnormal in 65 evaluations (80.3%) and the results of both tests were abnormal in 27 evaluations (33.3%). All fetuses diagnosed as being severely anemic by at least one of the hemoglobin criteria during cordocentesis had an abnormal result by at least one of the noninvasive tests. Before the second and third transfusions, the combined use of the CFI and MCA-PSV MoM predicted severe fetal anemia with 100% sensitivity. When the CFI and MCA-PSV MoM measurements were normal, the negative likelihood ratio was zero. CONCLUSION: When associated, CFI and MCA-PSV MoM were accurate predictors of severe fetal anemia.