In another study that compared mothers who released their children to those who raised them, mothers who released their children were more likely to delay their next pregnancy, to delay marriage, and to complete job training. However, both groups reached lower levels of education than their peers who were never pregnant.[124] Another study found similar consequences for choosing to release a child for adoption. Adolescent mothers who released their children were more likely to reach a higher level of education and to be employed than those who kept their children. They also waited longer before having their next child.[122] Most of the research that exists on adoption effects on the birth parents was conducted with samples of adolescents, or with women who were adolescents when carrying their babies—little data exists for birth parents from other populations. Furthermore, there is a lack of longitudinal data that may elucidate long-term social and psychological consequences for birth parents who choose to place their children for adoption.
Social workers and other professionals in the field of adoption began changing terms of use to reflect what was being expressed by the parties involved. In 1979, Marietta Spencer wrote "The Terminology of Adoption" for The Child Welfare League of America (CWLA),[184] which was the basis for her later work "Constructive Adoption Terminology".[185] This influenced Pat Johnston's "Positive Adoption Language" (PAL) and "Respectful Adoption Language" (RAL).[186] The terms contained in "Positive Adoption Language" include the terms "birth mother" (to replace the terms "natural mother" and "real mother"), and "placing" (to replace the term "surrender"). These kinds of recommendations encouraged people to be more aware of their use of adoption terminology.
Although adoption is today practiced globally, the United States has the largest number of children adopted per 100 live births. The table below provides a snapshot of Western adoption rates. Adoption in the United States still occurs at nearly three times those of its peers although the number of children awaiting adoption has held steady in recent years, hovering between 133,000 and 129,000 during the period 2002 to 2006.[52]
During the same period, the Progressive movement swept the United States with a critical goal of ending the prevailing orphanage system. The culmination of such efforts came with the First White House Conference on the Care of Dependent Children called by President Theodore Roosevelt in 1909,[33] where it was declared that the nuclear family represented "the highest and finest product of civilization" and was best able to serve as primary caretaker for the abandoned and orphaned.[34][35] Anti-institutional forces gathered momentum. As late as 1923, only two percent of children without parental care were in adoptive homes, with the balance in foster arrangements and orphanages. Less than forty years later, nearly one-third were in an adoptive home.[36]
Markedly different from the modern period, ancient adoption practices put emphasis on the political and economic interests of the adopter,[4] providing a legal tool that strengthened political ties between wealthy families and created male heirs to manage estates.[5][6] The use of adoption by the aristocracy is well documented; many of Rome's emperors were adopted sons.[6] Adrogation was a kind of Roman adoption which required the adrogator to be at least 60 years old.

In the 1970s, as adoption search and support organizations developed, there were challenges to the language in common use at the time. As books like Adoption Triangle by Sorosky, Pannor and Baran were published, and support groups formed like CUB (Concerned United Birthparents), a major shift from "natural parent" to "birthparent"[182][183] occurred. Along with the change in times and social attitudes came additional examination of the language used in adoption.