The Hospital Clínic Barcelona and the Blood Bank, pioneers in Spain in the transfusion of umbilical cord blood to extremely preterm infants with anaemia

Extremely preterm neonates, those born before 28 weeks of gestation, often need blood transfusions because they are especially vulnerable to anaemia. This is a common complication for these extremely preterm infants, weighing less than 1.5 kg, which is treated with transfusions of packed red blood cells from adult donors. Currently, in Catalonia, nearly 500 preterm infants are transfused each year with blood from adult donors.

A study published in 2025 in Italy showed that cord blood reduces the risk of complications associated with prematurity, such as retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), or necrotizing enterocolitis (NEC), and alleviates the side effects associated with adult transfusions In order to validate the technique and the feasibility of performing this type of transfusion in Catalonia, the Clínic and the Blood and Tissue Bank (BST) launched a clinical trial that was pioneering in Spain and in which 41 extremely preterm infants with anaemia participated.

The results of this trial, conducted between 2023 and 2025 and presented at the Congress of the Joint European Neonatal Societies, confirm that the health infrastructure available at the Clínic and the BST is viable for performing cord blood transfusions in our setting. “This is a more physiological alternative for the young recipients and improves the blood profile of these infants, which remains similar to that of preemies who do not require a transfusion", explains Dr Miquel Alsina, consultant in the Neonatology Department, within the Clínic Institute of Gynaecology, Obstetrics and Neonatology at the Hospital Clínic Barcelona, the initiator of the study.

Once Phase I of the clinical trial is completed, the next step will be a multicentre study with several maternity hospitals in Barcelona and with many more patients, which will begin in 2026 and is pending funding. According to Alsina, “the future goal is to be able to treat as many children as possible who need it.”

Blood with a ‘special’ haemoglobin 

Umbilical cord blood “contains a type of haemoglobin called foetal haemoglobin (HbF), which can be beneficial for preterm infants as it prevents damage from the overexposure to oxygen that adult haemoglobin causes in these infants. The red blood cells from umbilical cord blood would be a more physiological substitute and therefore a better alternative than conventional transfusion", adds Alsina. The good results of the previous study in Italy confirm that higher levels of HbF could protect against the excess oxygenation of vulnerable tissues such as the retina, helping to prevent retinopathy of prematurity and other complications.

Having a preterm infant is a significant maternal and child health issue, especially because of the complications associated with being born early, as these infants have immature organs and functions. The research carried out at the Clínic’s Maternitat Site and the Blood and Tissue Bank, which began in 2019, adds to the knowledge that has also recently been corroborated by some international studies that support the feasibility, security, and potential beneficial effects of transfusing cord blood to preterm infants. 

A new therapeutic use of umbilical cord blood

"This is a new use of umbilical cord blood in Catalonia, which reinforces the role of the umbilical cord being more than just a source of stem cells; for transplants in leukaemia patients, or for research, but also as an immediate and safe resource to improve the clinical care of the most vulnerable newborns,” explains Jesús Fernández, director of the BTS Cord Blood Bank. Both Fernández and Alsina are convinced that cord blood transfusion “can revolutionize transfusion in preterm neonates.” In this regard, Alsina does not rule out that “these results can be extrapolated to other populations of critically ill newborns who require red blood cell transfusions, such as infants with heart defects who require surgery,” but this is an option tied to the complicated availability of this type of blood. One of the objectives of the study was to demonstrate that cord blood was available, a “scarce product,” insists the head of the Cord Blood Bank, Jesús Fernández, who reiterates the collective call to increase donation, which has seen a sharp decline in recent times.

 “The decline in births and a lack of awareness of this need among mothers” are some of the factors “working against us,” indicates Fernández. In this regard, the Cord Blood Bank has launched a special appeal this year to meet the 2025 challenge of 1,500 cord blood donations and to maintain the multiple therapeutic possibilities of this blood, which is so rich in stem cells. “The effort and awareness must be collective because it is an altruistic donation that is currently scarce. It is necessary to spread awareness of this need among mothers, midwives, the healthcare system itself through its entire process of caring for pregnancy and childbirth, the Blood and Tissue Bank, and maternity hospitals", agree Alsina and Fernández.

One of the families participating in this study is that of Eira’s mothers, Elisabet and Sílvia, from Barcelona. Eira was born in 2024 at just 25 weeks due to an amniotic sac infection.  Eira was born weighing 700 grams and, like many preterm infants born with such low weight, she had to be intubated for her first few days for respiratory support, and she needed a blood transfusion. She responded well to all the initial treatment and made very good progress afterwards, considering her extreme prematurity at birth. At one and a half years old, and with the appropriate check-ups, she has progressed very satisfactorily.