A longitudinal study of hymenal morphology in the first 3 years of life

To document the effects of aging on hymenal morphology during the first 3 years of life in a cohort of nonabused girls.

Using a longitudinal design, we examined and photographed the external genitalia of 134 girls at 2 months or less and near 3 years of age; 42 of these girls were also examined near 1 year of age. The prevalence of each hymenal characteristic was calculated at each time, and differences were analyzed using the z statistic and McNemar change tests. Measurements of transhymenal diameters and the inferior rims were compared using a paired t-test.

Hymenal configuration in 65% (87 of 134) of the subjects changed between birth and 3 years, usually from annular or fimbriated to crescentic. External ridges observed at birth usually resolved by 3 years, whereas intravaginal ridges were observed more often in 3-year-olds (P = .00). Analysis by race showed that the prevalence of both superior and lateral notches decreased in whites, whereas the prevalence of intravaginal ridges changed only in blacks (P = .00). Sixty-eight percent (15 of 22) of the tags present at birth were not observed at 3 years, while nine tags formed during this period. Changes observed between 1 and 3 years included increases in the mean horizontal (P = .00) and vertical (P = .02) transhymenal diameters and in the prevalence of the crescentic configuration (P = .04).

Changes in hymenal morphology, which may vary by race, occur in the first 3 years of life. Alterations are more pronounced in the first year than in years 2 and 3. Physicians should understand the effects of aging on the hymen's appearance to differentiate normal development from post-traumatic or infectious changes.