In spite of there is no biological relationship between the child and the surrogate mother if you wish, she plays the most important role in the whole process, gestating and giving birth to the baby previously created by the biological mother eggs o an egg donor and the father’s sperm o a donor.
The Unites States are pioneers when coming to surrogate mothers, for a candidate to opt to subrogate, she needs to pass though a lot of tests and evaluations such as: physiological examination, controls of police reports, obstetrics examination, reviews of medical insurance policy, all type of medical examination and approve a selection process not only by the agency that hire them, also under the supervise of the doctors that will proceed to embryonic transfer o artificial insemination.
All of this contributes to have a very high level success in the gestating by substitution and in many cases we get excellent results in the first transfers.
The best way to choose a surrogate mother out of all the candidates, not only depends of these types of evolution, but yet the affinity that come out of both parts (surrogate mother and future parents), once they are introduced or put in contact.
When the time comes to make any decision we have to bear in mind the country where we are hiring the surrogate mother and the possible variants.