Perinatal outcomes and survival predictors of severe red‐cell alloimmunization treated by intrauterine transfusion

Abstract

Objective To evaluate perinatal survival rates and predictors in severely anemic fetuses that underwent intrauterine transfusion (IUT). Method This was a retrospective study of both Turkish and Syrian patients who underwent IUT for fetal anemia due to Rh alloimmunization between 2015 and 2019. The association between pretransfusion factors and perinatal survival was evaluated by multivariate logistic regression. Receiver operating characteristics (ROC) curves were used to identify the level of fetal hemoglobin deficits that predict perinatal survival. Results Eighty‐seven IUTs were performed in 42 pregnancies. Approximately 75% of fetuses were severely anemic and the overall perinatal survival rate was 50%. The survival rate was better in Syrian refugees compared to Turkish patients (71.4% vs. 39.3%, p < 0.05). In univariate analysis, hydrops presence (odds ratio [OR] = 0.2; 95% confidence interval [CI] = 0.05–0.7; p < 0.05), first IUT week (OR = 1.4; 95% CI = 1.1–1.8; p < 0.05), pretransfusion hemoglobin level (OR = 1.99; 95% CI = 1.22–3.27; p < 0.05), hemoglobin deficit (OR = 0.5; 95% CI = 0.3–0.8; p < 0.05), and birth week (OR = 2.3; 95% CI = 1.3–3.9; p < 0.05) were associated with survival. However in a multivariate analysis, only hemoglobin deficit (OR = 0.47; 95% CI = 0.22–0.99; p < 0.05) and birth week (OR = 3.3; 95% CI = 1.1–10.3; p < 0.05) were found to be associated with survival. On ROC analysis, a hemoglobin deficit of ≤6.25 g/dl showed a sensitivity of 0.95 and specificity of 0.62 for predicting perinatal survival. Conclusion Despite the improvement in the treatment of fetal anemia, perinatal survival rate remains extremely low in severely anemic cases. Among pretransfusion factors, hemoglobin deficit seemed to be most important in predicting survival during fetal anemia.

Effective management of foetal anaemia in Rh(D) alloimmunised pregnant women with intrauterine transfusion: a Systematic Review

“…One of the studies showed a 50 % chance of survival which is a considerably different result to the other studies. 5 This survival rate was the lowest recorded, but this was due to the large number of severely hydropic cases in the cohort. It was found that this study included severely anaemic foetuses at first IUT and the majority of participants had severe hydrops which probably impacted on the result.…”

“…Most studies identified a similar low range of foetal death, but four studies showed higher weighting on mortality. 3 , 5 , 27 , 29 These studies had more cases of hydrops and more procedures performed which could have led to an increase in PR complications hence, higher mortality. One of the studies had a mean gestational age of 20.4 weeks at first IUT with treatment being shown to be less effective.…”

“… 4 Prophylactic anti-D immunoglobulin is standard treatment in the prevention of alloimmunisation thereby decreasing the rate of foetal anaemia, however it is not widespread in developing countries due to the lack of awareness and availability in remote areas. 5 , 6 Also, once alloimmunisation occurs it cannot be administered during pregnancy. 4 It is a modern practice to use maternal plasma in alloimmunised women to determine Rh(D) foetal antibodies.…”

“… 15 , 16 Foetal anaemia benefits from IUTs with survival rates of 94 % for non-hydropic foetuses and 74 % for hydropic foetuses. 5 , 9 Mortality outcomes have improved due to the accuracy and reliability of predicting anaemia and the availability in utero treatment.…”