Surrogacy is an arrangement in which a woman carries and delivers a child for another couple or person. This woman may be the child's genetic mother (called traditional surrogacy), or she may carry the pregnancy to delivery after having an embryo, to which she has no genetic relationship, transferred to her uterus (called gestational surrogacy). If the pregnant woman received compensation for carrying and delivering the child (besides medical and other reasonable expenses) the arrangement is called a commercial surrogacy, otherwise the arrangement is sometimes referred to as an 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.

The social parents (that is, those that intend to raise the child) may arrange a surrogate pregnancy because of female infertility, or other medical issues which may make the pregnancy or delivery impossible, risky or otherwise undesirable. The social mother could also be fertile and healthy, and prefer the convenience of someone else undergoing pregnancy, labor, and delivery for her. The intended parent could also be a single man or woman wishing to have his/her own biological child. Some same-sex couples turn to surrogacy as an option to becoming parents.

The legality of surrogacy arrangements vary widely between jurisdictions.