Changes in genital anatomy and microbiology in girls between age 6 and age 12 years: a longitudinal study

To study changes in genital anatomy and occurrence of human papillomavirus and Gardnerella vaginalis in girls resulting from growth and development.

At age 11-12 years, an invitation was sent to 180 girls to attend a follow-up examination. All girls had previously participated in a study exploring anogenital anatomy and microbiology in children selected for non-abuse at age 5 and 6. The genital area was examined with a colposcope and microbiological samples for Gardnerella vaginalis (GV) and human papillomavirus (HPV) were collected. GV was identified by conventional criteria and HPV by a PCR method.

Thirty-one girls were examined twice, at mean age 5.7 and 12.0 years. At first examination all were pre-pubertal. At second examination 21 girls were B2/P2 or above. Significantly more girls had developed a structure called a fossa groove. A thick and redundant hymen with a tendency of folding outward was more common at the second examination. Two girls had GV and one girl had HPV-16 identified. Another girl was classified to have a deep notch and a probable transection in her hymen, and this girl reported a painful insertion of a tampon. All girls denied sexual activity.

The main genital finding in girls entering puberty is the hymen becoming thick and redundant with a tendency of folding out. In the study findings associated with sexual activity were discovered in two girls, and the possibility of alternative explanations is discussed.