Surrogacy is an arrangement in which a woman carries and delivers a child for another couple or person. Most commonly, the surrogate is impregnated with an embryo created with the egg of another woman. This is termed "gestational surrogacy." In "traditional surrogacy," the surrogate is also the child's genetic mother.

Surrogacy is often used to allow women who are unable to carry a child, but whose eggs are viable, to have a child genetically related to both her and her partner. In other cases, "intended parents" including gay couples use surrogates and third-party eggs to create a child genetically related to one member of the couple.

Some surrogacy arrangements involve no financial considerations between the parties involved, or compensate the surrogate only for expenses and, perhaps, lost wages involved with carrying the child. Increasingly, however, surrogacy is a commercial arrangement.

A number of countries and U.S. states prohibit commercial surrogacy arrangements, or limit compensation to expenses and lost wages. Others have no regulations and market-like conditions prevail.

In the U.S., costs for surrogacy are upwards of $100,000. This has led to the practice known as "reproductive tourism," in which prospective parents travel to avoid regulations or to save money. Some people seeking surrogates, especially Europeans, come to the U.S., but even more go to less developed regions where fertility practices are loosely regulated, if at all. India, perhaps the world's number one hub for cross-border medical treatment, has a reproductive tourism market with revenues estimated to be over half a billion dollars.

Industry supporters often defend this practice saying that women in developing countries can earn many times a normal salary by being a surrogate. However, women's health and human rights advocates and scholars raise serious concerns about how these arrangements take advantage of socially marginalized women, compromising their health and reproductive autonomy to make a profit. Some surrogate brokers, for example, routinely perform C-sections on all of their surrogates so that hiring parents can schedule to be present for the delivery. There have been several scandals involving the exploitation of surrogate mothers or fraud committed by brokers on would-be parents.

There may be legal issues after the birth of a child to a foreign surrogate. Questions of citizenship remain unresolved in several jurisdictions.