Surrogacy is a process or arrangement in which a woman carries and delivers a child for another couple or person. The woman who readily agrees for the same is often referred to as surrogate mother. If a surrogate mother is genetically related to the child it's called traditional surrogacy and if the mother is not related to the child genetically it is termed as gestational surrogacy. In a traditional surrogacy, the child may be conceived through artificial insemination using fresh or frozen sperm or impregnated through intrauterine insemination or intracervical insemination performed at a health clinic. A gestational surrogacy would require instilling a clinically created embryo previously to be instilled in the womb of the surrogate mother.
A couple would generally opt for surrogacy if the mother is unable to conceive due to some medical condition or if it is diagnosed that a pregnancy could put her on high risk or make it life threatening for the mother.
While opting for surrogacy it is important to choose the surrogate mother wisely. Ideally after a medical check up to see if the surrogate mother is capable of taking the strains of pregnancy in her stride. Also surrogacy doesn't always promise results. So one should be prepared for the outcome. The success of surrogacy depends on a lot of factors - the health of the surrogate mother, the procedures involved, age of the egg donor, the quality of the embryo produced by the couple before instilling it on the womb of the surrogate mother.
Surrogacy also involves complicated legal issues too. Always sought for legal opinion before you opt for surrogacy.