The practice has several names in various historical and sociological literatures. It is sometimes called informal adoption, to distinguish it from the formal legal process overseen by courts and agencies. It is sometimes described as family absorption, reflecting the way a child is incorporated into an existing family structure rather than transferred to an external one. In some communities and periods, it was simply understood as what families did — not a special arrangement requiring a name, but a default response to a particular circumstance.
The scale of this practice in the mid-twentieth century United States is difficult to quantify precisely because, by its nature, it operated outside official documentation. The children involved were typically registered with amended or falsified birth certificates that listed the raising grandparents as the parents, and the biological mothers were listed as sisters or simply absent from the official family record. No central agency tracked these arrangements, and many were never revisited or revealed.
What can be documented is the social pressure that produced them. The unmarried pregnancy in a religious, working-class community in the 1930s was a specific kind of social crisis. It was visible: it could not be hidden indefinitely in the way that some private matters can be managed. And it carried consequences that extended across the family rather than attaching only to the woman who had become pregnant. The parents of an unmarried pregnant daughter faced questions about their moral oversight of their household. The siblings faced questions about their family’s values. The church community rendered judgments.