Bronchopulmonary dysplasia (BPD) is a disease that affects preterm newborn patients, preventing their lungs from developing properly. Allogeneic fetal stem mesenchymal cells from umbilical cord could reduce the prevalence of BPD in this patients.

Bronchopulmonary dysplasia (BPD) is a disease that affects preterm newborn patients, preventing their lungs from developing properly, and it is a disease that is nowadays increasing due to the improvement in the survival of this patients (affecting 15-50% of them).

In the Fase I Clinical Trial, the use of allogeneic fetal stem mesenchymal cells from umbilical cord proved to be safe, with no mortality or Adverse Events reported. The Fase II Clinical Trial is based in the hypothesis that the administation of mesenchymal stem cells is not only safe but feasible and can help reducing the chance of a preterm newborn patient developing BPD.

Inclusion Criteria:

• Alive newborns weighing ≤ 1250 grams and GA ≤ 28 weeks, who are on mechanical ventilation with a FiO2 ≥0.3 between days 5 and 14 of life, with no immediate extubation foreseeable.

Exclusion Criteria:

• Presence of another concomitant congenital pathology at the time of inclusion: pulmonary malformations with compromised pulmonary function, active pulmonary haemorrhage, severe pulmonary hypoplasia, renal malformations with systemic compromise, congenital heart disease, polymalformative syndromes, chromosomopathies.
• Presence of refractory haemodynamic instability of any cause at the time of inclusion.
• Presence of severe neurological damage at the time of inclusion (HIV grade III or higher).
• Patients who have required major surgery in the 72 hours prior to inclusion.
• Patients who have necrotising enterocolitis (NEC) grades ≥II at the time of inclusion, according to the Bell classification.
• Patients who are children of a mother with HIV