Surrogacy is an arrangement in which a woman carries and delivers a child for another couple or person. This woman, the surrogate mother, may be the child’s genetic mother (called traditional surrogacy), or she may be genetically unrelated to the child (called gestational surrogacy).
If the surrogate receives compensation beyond the reimbursement of medical and other reasonable expenses, the arrangement is called commercial surrogacy; otherwise, it is often referred to as altruistic surrogacy.
In a traditional surrogacy, the child may be conceived via home artificial insemination using fresh or frozen sperm or impregnated via IUI (intrauterine insemination), or ICI (intracervical insemination) performed at a health clinic.
A gestational surrogacy requires the transfer of a previously created embryo, and for this reason the process always takes place in a clinical setting.
The intended parent or parents, sometimes called the social parents, may arrange a surrogate pregnancy because of female infertility, other medical issues which make pregnancy or delivery impossible, risky or otherwise undesirable, or because the intended parent or parents are male. The sperm or eggs may be provided by the ‘commissioning’ parents, but donor sperm, eggs and embryos may also be used.
Although the idea of vanity surrogacy is a common trope in popular culture and anti-surrogacy arguments, there is little or no data showing that women choose surrogacy for reasons of aesthetics or convenience.
The legality and costs of surrogacy vary widely between jurisdictions, with the result that there is a high rate of international and interstate surrogacy activity.
Definition from: http://en.wikipedia.org