Umbilical cord blood (UCB) is used for leukemia patients and other serious blood disorders worldwide. (3) It has also been recently used for other therapeutic applications such as wound treatment, red blood cell transfusion, or cellular or regenerative therapy. Until now, cord blood banks have worked to have many units in reserve to offer maximum compatibility with patients.

The priority is to increase the quality of cord blood by collecting units that have more stem cells with less contamination so that more patients can benefit, that is, improving the efficiency of the process.

The conventional in utero technique allowed for a more rapid diffusion of cord blood donation programs as it does not require accessories or additional personnel to carry it out. The UCB donation program was initiated in Catalonia in 1995, and since then, this has been the technique used (www.bancsang.net/info-corporativa/qui-som). Some comparisons have been made in the scientific literature with the results found . Currently, there are some new applications of UCB that require its use in fresh form, and it would be beneficial to minimize the risk of bacterial contamination that seems to be reduced with ex utero collection. Therefore, the proposition for this study is to confirm equivalence in quality characteristics and create opportunities for its extensive application.

Currently, cord blood donation is offered to all expectant mothers, provided that the donor does not have any medical exclusion. A very small number of the collected units are suitable for clinical use once processed, making donation programs truly inefficient. This inefficiency generates a workload and waste of public resources that are limited and can also cause ethical dilemmas. Therefore, new strategies are needed to increase the efficiency of donation programs. The Blood and Tissue Bank (BST) has an efficiency improvement study underway using the ex-utero collection technique. The development of this methodology will allow later to propose expanded collection methods, such as the simultaneous collection of cord blood and placenta.

The update of new protocols in childbirth care encourages to explore new systematic umbilical cord blood collection methods with the following objectives: to intervene less in the delivery room obtaining products of equal quality and less contamination and to facilitate the simultaneous donation of UCB and placenta in the future. To ensure that the units have maximum quality, both cellular and free of bacteriology, and can be used safely, the investigators propose the implementation of ex utero cord blood collection. The ex-utero UCB collection involves minimal manipulation, allowing for better cord asepsis. After the birth of the baby and cord clamping at one minute, the investigators wait for the delivery of the placenta and proceed to obtain the ex-utero UCB sample. Thanks to this technique, residual cord blood can be obtained, and the placenta can be collected simultaneously, maintaining the same volume as in in utero collection and reducing contamination and hemolysis of the samples.

This technique poses no risk to either the mother or the baby. The ex-utero cord blood collection technique is a validated technique used in different studies.

To verify these data in our environment and propose a change in the cord blood collection strategy in public banks, this study has been designed.

If the investigators demonstrate that this methodology meets quality objectives, similar to the in-utero technique but significantly reducing associated contamination from the delivery field and the presence of hemolysis, the cord blood bank can implement this new systematic method in centers with highly trained collection personnel, releasing obstetric professionals from their intervention in the delivery room and favoring better quality of the products obtained.

Inclusion Criteria:

• 18 years old
• Geographical origin and history of known travels
• Absence of potentially transmissible diseases (infectious, hematological, and autoimmune)
• Absence of diseases that can alter prenatal obstetric variables: multiple pregnancy, pregestational diabetes mellitus, intrauterine growth restriction, hypertensive states of pregnancy or chronic arterial hypertension, and fetal pathology.
• Any type of delivery: vaginal delivery and cesarean section.
• Deliveries from week 37 or higher.
• Standardization of the timing of clamping in all cases to one minute.

Exclusion Criteria:

• Pregnant women who meet the exclusion criteria to be cord blood donors.