Historically, there are two types of surrogacy. The original type was called classical surrogacy, and involved inseminating the surrogate with the sperm of the father-to-be. The surrogate therefore contributed a genetic egg and was therefore the genetic and biological mother of the child – who was then given to the intended parents after delivery. This type of surrogacy now rarely occurs. Since the introduction of in vitro fertilization technology it is now possible to perform a more acceptable type of surrogacy – called gestational surrogacy. In this particular process the gestational carrier is not the genetic parent of the child.
For this to take place, the genetic mother undergoes in vitro fertilization. The eggs are harvested, and fertilized in the laboratory with her partner's sperm. At the same time that this process is taking place, the gestational surrogate has her uterus prepared artificially with hormones. The fertilized egg develops into an embryo, which is usually cultured in the laboratory for between 3 and 5 days. The embryo/embryos are then selected and inserted into the uterus of the gestational carrier. After birth, the surrogate then gives the child back to the intended parents.
Surrogacy can be an extremely rewarding process for both the surrogate and the intended parents. The success of their relationship is very dependent on the process. Adequate psychological assessment, careful discussion and explanation about expectations are paramount to a good result.