In utero transfusions (IUTs) appeared to support improved survival and other perinatal outcomes in a study involving patients with alpha thalassemia major (ATM). Findings of this study were reported in the journal Blood Advances.

“Despite the growing understanding that fetal therapy is an option for ATM, there is a relative reluctance to offer IUTs for this condition, partly because of the limited literature demonstrating the benefits of fetal therapy on postnatal outcomes,” the study investigators explained in their report. They set up an international registry ( Identifier: NCT04872179) based at University of California, San Francisco (UCSF) to identify factors and outcomes associated with the use of IUTs in patients with ATM.

The investigators obtained data on parental demographics, prenatal findings, IUT details, neonatal outcomes, and postnatal treatment approaches received from patients in the registry. Survival to discharge in neonates was the primary study outcome, and several secondary outcomes were also assessed. Results were also evaluated in combination with data from 2 previously published case series.

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In 60 fetuses with ATM in the UCSF registry, among 49 with a prenatal ATM diagnosis, there were 30 medical abortions at a mean gestational age of 21 weeks. Other patients were categorized into 3 groups: group 1 included 14 patients who were prenatally diagnosed and were alive at hospital discharge; group 2 included 5 patients who were prenatally diagnosed but who had died in the perinatal period; and group 3 included 11 patients who were postnatally diagnosed and who were alive at discharge.

In group 1, all fetuses had been given 2 or more IUTs. Fetuses in group 2 had been given 0 to 1 IUTs. Patients in group 3 had been diagnosed postnatally and thus had not received IUTs. Among 19 patients who had received IUTs, there were 16 with continued pregnancies. Deliveries occurred preterm in 3 of these pregnancies.

Earlier use of IUT appeared correlated with improved Vineland-3 scores (r, -0.72; P =.02). This served as an indicator of improved neurodevelopment.

Combining data from the patients in the UCSF registry with the 2 previously published case series resulted in a total of 48 patients. Among these there were 27 patients who had been given 2 or more IUTs and 21 who had received 0 to 1 IUTs.

Overall, the researchers found that the use of 2 or more IUTs was associated with better outcomes than seen with 0 to 1 IUTs. These included resolution of hydrops (P =.01), delivery occurring at 34 or more gestational weeks (P =.003), and 5-minute appearance, pulse, grimace, activity, and respiration scores of 7 or higher (P =.01). This combined analysis also suggested better neurodevelopmental outcomes for those given 2 or more IUTs, compared with 0 to 1 (P =.01).

“The dramatically improved perinatal and neurodevelopmental outcomes of fetuses with ATM who received 2 or more IUTs demonstrates a clear rationale for fetal therapy for this historically fatal disease,” the investigators concluded in their report.

Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.


Schwab ME, Lianoglou BR, Gano D, et al. The impact of in utero transfusions on perinatal outcomes in patients with alpha thalassemia major: the UCSF registry. Blood Adv. 2023;7(2):269-279. doi:10.1182/bloodadvances.2022007823