Appearance of the hymen at birth and one year of age: a longitudinal study.

The increase in the number of prepubertal girls who require evaluation of possible sexual abuse creates a need for detailed information, not previously available from cross-sectional studies, on the influence of aging on the hymen's appearance. This study was undertaken to evaluate and document, using a longitudinal design, changes in the hymen's morphology in 62 girls without a history of sexual abuse between birth and their first birthday. Labial agglutination extensive enough to obscure the inferior half of the hymen was observed in 5 girls (8%) at 1 year of age. Thirty-three (58%) of the remaining 57 infants experienced a marked decrease in the amount of their hymenal tissue between birth and 1 year. Significantly more infants at 1 year of age had a crescentic configuration (0% vs 28%), and significantly fewer had an external ridge (82% vs 14%) as compared to the newborn period. An annular hymen with a central or ventrally displaced opening progressed to a crescentic hymen in 13 children by 1 year, 77% (10/13) of whom were observed to have a notch (cleft) at the 12 o'clock position on the earlier study. A superior notch appeared for the first time in 9 girls. Lateral notches resolved in 5 cases and persisted in 2. Inferior notches between the 4 and 8 o'clock positions were not observed at birth or 1 year. Hymenal tags resolved in 2 instances, persisted in the same location in 2, and appeared for the first time in 4 cases.(ABSTRACT TRUNCATED AT 250 WORDS)