The Growth and Development of the Pelvis of Individual Girls Before, During, and After Puberty *

In 1937, as a part of the research program of the Adolescence Study Unit of the Yale University School of Medicine, we undertook a study of the changes in the size and shape of the bony pelvis of girls during puberty and early adolescence. When that study was begun, the senior author was a member of Dr. Edgar Allen's staff in the Department of Anatomy and the program was planned in consultation with him. We are happy to contribute to Dr. Allen's memorial number of the YALE JOURNAL OF BIOLOGY AND MEDICINE this report of an investigation which owes so much to his counsel and guidance. Through the generous cooperation of the officials of a New Haven orphanage, we were able to recruit for this study 107 girls, who ranged in age from 5 years to 15 years and 2 months at the time the investigation was started. They were examined at intervals of approximately one year; the majority of the girls received four successive annual examinations and the remainder, five. In addition, ten of them were re-examined six years after their first examination. As is usually the case in longitudinal studies of human growth and development, some children were lost, for one reason or another, during the course of the study. Only 90 of the original number were available at the time of the fourth examination. At each examination the girls were weighed, measured, and certain observations regarding the status of their various secondary sexual characters were recorded. In addition, an x-ray film was made of the hand and wrist, in order to determine their skeletal age, and antero-posterior and lateral films of the pelvis were made according to the technic of Thoms' and of Thoms and Wilson.7