"gestational mother" is a correct and usable phrase in written English.
It is used to refer to a woman who carries and gives birth to a child that is not genetically related to her. This term is commonly used in situations involving surrogacy or assisted reproduction. Example: The couple chose to use a gestational mother to carry their child, as the wife was unable to carry a pregnancy herself.
Likewise, in the case of gestation, since the gestational mother is guaranteed to be identifiable at birth, it is in the best interests of the child that she be regarded as the mother (Annas 1984).
"The sole position is that the religious status of the child follows that of the gestational mother in cases involving surrogacy and in all other cases," said Rabbi Joel Meyers, executive vice president of the Rabbinical Assembly.
In reproductive contexts in which a child's gestational mother differs from its genetic mother as in egg (or embryo) donation and gestational surrogacy it is therefore the gestational mother who has the primary claim to parental rights and responsibilities.
Third, genetic parents do not provide the material from which the child is constituted in utero; that derives from the gestational mother, not the genetic parents (Silver 2001).
This line of argument can be expanded to include people besides the gestational mother who have taken a parental role in rearing a child (Millum 2010).
Surrogacy arrangements can take many forms, but the most widely discussed involves two parties, a contracting couple and a "surrogate" or gestational mother.
Gestational mothers typically invest a substantial amount of effort into the child.
The implication of this view is that at birth, gestational mothers deserve full parental rights regardless of any prior contractual arrangements.
(Biological parents need not be social parents, as biological parents give up children for adoption, donate gametes, or work as gestational mothers).
While this account appears to give a special role to gestational mothers, it can include parenting partners who help bear the costs or contribute to establishing a relationship (for example, by viewing an ultrasound image together).
