Adoptions can occur either between related family members, or unrelated individuals. Historically, most adoptions occurred within a family. The most recent data from the U.S. indicates about half of adoptions are currently between related individuals. A common example of this is a "stepparent adoption", where the new partner of a parent may legally adopt a child from the parent's previous relationship. Intra-family adoption can also occur through surrender, as a result of parental death, or when the child cannot otherwise be cared for and a family member agrees to take over.
Europe's cultural makeover marked a period of significant innovation for adoption. Without support from the nobility, the practice gradually shifted toward abandoned children. Abandonment levels rose with the fall of the empire and many of the foundlings were left on the doorstep of the Church. Initially, the clergy reacted by drafting rules to govern the exposing, selling, and rearing of abandoned children. The Church's innovation, however, was the practice of oblation, whereby children were dedicated to lay life within monastic institutions and reared within a monastery. This created the first system in European history in which abandoned children did not have legal, social, or moral disadvantages. As a result, many of Europe's abandoned and orphaned children became alumni of the Church, which in turn took the role of adopter. Oblation marks the beginning of a shift toward institutionalization, eventually bringing about the establishment of the foundling hospital and orphanage.
More recent research found that in a sample of mothers who had released their children for adoption four to 12 years prior, every participant had frequent thoughts of their lost child. For most, thoughts were both negative and positive in that they produced both feelings of sadness and joy. Those who experienced the greatest portion of positive thoughts were those who had open, rather than closed or time-limited mediated adoptions.
Foster care adoption: this is a type of domestic adoption where a child is initially placed in public care. Many times the foster parents take on the adoption when the children become legally free. Its importance as an avenue for adoption varies by country. Of the 127,500 adoptions in the U.S. in 2000 about 51,000 or 40% were through the foster care system.