The fertilization of the egg may take place in a number of ways, each of which has implications for the genetic relationship of the resulting child with the surrogate and the future parents. There are two main types of surrogacy: gestational surrogacy and traditional surrogacy. In the United States, gestational surrogacy is more common than traditional surrogacy and is considered less legally complex.
Traditional surrogacy (also known as partial, genetic, or straight surrogacy) involves natural or artificial insemination of a surrogate. If the intended father’s sperm is used in the insemination, then the resulting child is genetically related to the intended father and genetically related to the surrogate. If donor sperm is used, the resulting child is not genetically related to either intended parent but is genetically related to the surrogate.
In some cases, an insemination may be performed privately by the parties without the intervention of a doctor or physician. In some jurisdictions, the ‘commissioning parents’ using donor sperms need to go through an adoption process in order to have legal rights in respect to the resulting child. Many fertility centers which provide for surrogacy assist the parties through the process.
Gestational surrogacy (also known as host or full surrogacy) was first achieved in April 1986. It takes place when an embryo created by in vitro fertilization (IVF) technology is implanted in a surrogate, sometimes called a gestational carrier. Gestational surrogacy may take a number of forms, but in each form the resulting child is genetically unrelated to the surrogate:
- the embryo is created using the intended father’s sperm and the intended mother’s eggs. The resulting child is genetically related to both intended parents.
- the embryo is created using the intended father’s sperm and a donor egg where the donor is not the surrogate. The resulting child is genetically related to the intended father.
- the embryo is created using the intended mother’s egg and donor sperm. The resulting child is genetically related to the intended mother.
- a donor embryo is implanted in a surrogate. Such an embryo may be available when others undergoing IVF have embryos left over, which they donate to others. The resulting child is genetically unrelated to the intended parent(s).