Objective To explore the relationship between vaginal intraepithelial neoplasia (VaIN) and vaginal microecology in postmenopausal women.

Methods Postmenopausal women admitted to the Medical Center for Diagnosis and Treatment of Cervical Disease of Obstetrics and Gynecology Hospital, Fudan University from May 2020 to August 2020 were included. For patient who carried human papillomavirus (HPV) or with abnormal liquid-based cytologic test (LCT) result, further colposcopy was performed (biopsy when necessary). Totally, 160 patients with VaIN were assigned to the lesion group, 50 healthy postmenopausal women were assigned to the normal group. The results of vaginal microecology examination were compared between the two groups.

Results The vaginal microecology of postmenopausal women was generally out of balance: diversity increased, density reduced, positive rate of hydrogen peroxide increased significantly, and G⁺ brevibacterium increased (P < 0.05). Compared with normal group, the mall amounts of lactobacillus reduced and diversity increased, positive leucocyte esterase increased, positive acetylglucosaminidase decreased, and abnormal Nugent scores increased in the lesion group (P < 0.05). The results of multiple-factor analysis showed that VaIN was related to the increased positive leucocyte esterase, small amounts of lactobacillus, and reduced diversity. For positive leucocyte esterase and small amounts of lactobacillus, the odds ratio (OR) value was 1.251 (95%CI 1.101 4-1.421 1) and 1.242 (95%CI 1.031 3-1.496 7), respectively, while reduced diversity had the OR value of 0.791 (95%CI 0.672 5-0.931 1).

Conclusions The changes in vaginal microecological environment, especially the positive leucocyte esterase increases, lactobacillus decreases, and diversity increases, are associated with the incidence of VaIN.