Quantitative observations of hymens in prepubescent females selected for non-abuse

The maximum hymenal opening was evaluated quantitatively in 111 prepubescent females during routine physical examinations in a pediatric subspecialty office. For comparison, an additional 53 females referred by child protective agencies were also examined. Analysis of data show "non-abused" groups may be separated statistically from "abused" groups on the basis of area of hymenal opening. The mean area for the "non-abused, non-masturbate" group was 6.4 mm2. The upper limit of area (mean + 3 S.D.) of hymenal opening in this group was 24.1 mm2. A child having a hymenal opening diameter of 6.94 mm or less has a 99% chance of being in the "non-abused" group. The area of hymenal opening for "non-abused" groups did not change with increasing age, height or weight. A skilled pediatrician knowledgeable in the area of sexual abuse may obtain clinically relevant information with ordinary office equipment and trained personnel. Regular and repeated observations of genitalia during routine health maintenance examinations are vital baseline measurements for the physical and mental health of young female patients.