This dolphin is “desensitized” to accept human presence. It is the result of many hours of training based on trust of the animal with his coaches. In wildlife it would be almost impossible to capture it, due to the natural fear of dolphins, especially when a female is about to give birth, because they will instinctively try to avoid anyone who might be a threat to breeding.
Video of giving birth
(total 4:32min | from Delphinus & Grupo Via Delphi)
More videos about delfines etc.: http://en.nauticwebnews.com/tag/animals/