birth parent
noun [ C ] uk/ˈbɜːθ ˌpeə.rənt/ us/ˈbɝːθ ˌper.ənt/
生身父母;生父;生母
the woman who gave birth to a child or the man who helped to conceive a child (= cause a baby to begin to form), although she or he may not now be the child's legal parent