MADRID, Jan. 19 (Xinhua) -- The Gregorio Maranon Hospital here on Friday said it successfully carried out a heart transplant on a five-month-old baby despite the donor and the receiver having incompatible blood types.

The operation means Spain is the third European country to carry out this kind of operation behind Britain and Germany, while similar treatment has also been successful in Australia and the United States.

Speaking on Spanish TV, hospital spokesperson Dr Manuela Camino said the operation took four hours and the baby, named Carla, is progressing well and could be allowed to leave hospital in a matter of days.

Carla had been diagnosed as having a heart defect while her mother was pregnant, but the operation could not be carried out until she had gained sufficient weight.

Camino explained that in order for this kind of transplant to take place it is necessary to use blood free from antibodies. In order for this to happen, the hospital uses a technique of exchange transfusion after the patient is included in the transplant program and during the operation.

"From now on, babies less than a year old will only have to have sufficient weight in order to have a transplant operation," she added.

The Gregorio Maranon Hospital hopes that the adoption of this technique will allow it to increase the number of heart transplant operations for babies under the age of one by 50 percent and that the chance of a baby needing a new heart having a transplant will rise from 60 percent to 90 percent.