Parents today proudly announce the weight of each new child, along with the baby's height, name, and sex. When did the practice of weighing newborns begin? And why?
Ezra Stiles, a Yale-educated minister in colonial Rhode Island, weighed and measured each of his children at birth and at regular intervals thereafter. Once he weighed the children before breakfast and again after dinner to see how much they had gained that day. But Stiles, who was a friend of Benjamin Franklin, was hardly typical in this regard. In her study of early American diaries, Laurel Thatcher Ulrich found that childbirths and baby weights were mentioned casually, if at all. For example, my wife was "delivered of a son" and I "sold a Cow," wrote a New Hampshire farmer in 1755. A midwife in Maine noted in passing that George Thomas's son was "more than the lite side of Mr. Densmore's stilyards would weigh." (A stilyard, or steelyard, is an unequal-arm weighing instrument, while a balance has two arms of equal length. Both forms are of ancient origin, and both are still used today.)
The practice of baby weighing picked up somewhat in the early 19th century. The Boston Medical Intelligencer advised physicians to record the birth of each infant, with weight and peculiarities of structure or condition, and to update this record annually. Like Stiles before him, the author of this 1826 article had no theory to test, but trusted that patterns would emerge from masses of data. Advertisements for bibles with pages designed for registering vital statistics first appeared about the same time.
Popular attention to the subject increased markedly after the Civil War. Readers of Godey's Lady's Book learned about a "wee morsel of a baby" trussed up in papa's new bandanna handkerchief and "swung from the hook of a pair of steelyards, as if it had been born into cannibal country, and were to be disposed of in the shambles, at so much per pound." "Weighing the Baby"—a poem by Ethel Lynn (aka Ethel Lynn Beers)—celebrated the emotional weight of parental love as well as the physical weight of the child. John Rogers's "Weighing the Baby"—a whimsical plaster statuette introduced in the U S. centennial year of 1876—was a big hit, with thousands of example sold. The Family Record, Biographic and Photographic (1868) was designed to hold photographic portraits, as well as data on heights and weights at different ages.
Florence Nightingale did not mention weighing in her Notes on Nursing for the Labouring Classes (1861). Nor did most other medical texts of the period. By the 1890s, however, the medical community had become interested in the subject. Dr. Mary Putnam Jacobi explained that "abnormal irregularities" of weight can indicate malnutrition, and thus a good balance used for weighing a child should be found in every well-appointed nursery. Dr. Edward Reynolds agreed, stating in his Practical Midwifery (1892) that "Nothing is more important in the routine care of infancy than the daily weighing of the child." Similar advice was given by the visiting nurses who cared for many Americans who could not afford a physician. It also appeared in Infant Care, an inexpensive and enormously influential book that the federal Children's Bureau published in 1914; by 1987, there were 60 million copies in print.
At this same time, the business community began offering scales for weighing babies, and books in which to record developmental milestones.
It is easy to show that weighing babies became increasingly widespread during the 19th century, but harder to understand why. The rise of pediatrics as a medical specialty was clearly important, as was the recognition that rapid fluctuations in weight might indicate the need for medical intervention. While statistical studies may not be as extensive as we might wish, many Americans knew that infant mortality was high, especially in urban areas with tainted water, poor sanitation, and crowded living conditions. Commercial baby foods may have been a boon for mothers who could not nurse or obtain the services of a wet nurse, but advertisements such as those promising "Thin babies become plump babies when fed with Mellin's Food" suggest concerns with products of this sort. The increasing importance of science in many facets of American life also contributed to this story. So too did the several European studies that determined the weights of "average" and "abnormal" children. But why some people thought that others might be interested in the weight of their babies remains a puzzlement.
Deborah Warner is a curator of the Division of Medicine and Science who blogs about relations between science and culture.