Surrogacy is only required after failure of attempts to conceive or carry a child. A patient with congenital and acquired uterine abnormalities or in case pregnancy poses a risk for the mother, may  need a gestational carrier.  

Babies born with this method will have the genetic codes of their mother and father. In other words, the biological mother and father are the ones who give the egg and the sperm. The baby won’t have e genetic relation with the gestational carrier. 

Same sex couples, single woman and single men may have surrogacy treatment. What makes it such an essential and valuable part of the fertility process is that it can become the final solution.