A pregnancy where a woman other than the mother carries the fetus. This usually occurs in cases where the mother has had a hysterectomy and has no uterus, but may also occur when the mother has an illness that would make labor and delivery too dangerous for her.
A form of collaborative reproduction in which the woman who is the surrogate for the intended pregnancy receives embryos from the commissioning infertile couple, who have undergone in vitro fertilisation, then, by becoming pregnant, carries (or 'gestates') the pregnancy, gives birth, and then gives up the baby to the baby's genetic parents. In principle the practice can be done for altruistic or commercial reasons.