Relationship between menstrual cup use and vaginal microbiota

• Grant number: 19/21696-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2019
• End date: January 31, 2021
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Márcia Guimarães da Silva
• Grantee: Beatriz Cassolatti Graciolli
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Introduction: Menstrual cups are reusable flexible collectors made of hypoallergenic silicone and adjustable to the body. They were created in the 1940s, but only recently this method of menstrual management has started to gain more users. Besides the economic and environmental advantages, it is possible that the use of menstrual cup influences modifications in vaginal microbiota and its adverse consequences compared to the use of sanitary pads. Patients and Methods: This is a prospective longitudinal study with women in reproductive age, with regular menstrual cycles, whose method of menstrual management is sanitary pad. In the first three menstrual cycles, participants will be instructed to use their usual method of menstrual management (sanitary pad). In the three consecutive cycles, they will be oriented to use the menstrual cup that will be offered by the research group. At recruitment (M1) and at the subsequent visits (M2 to M6), immediately after the interview to obtain information of gynecological background and sexual behavior, all women will undergo a gynecological examination, with insertion of a not lubricated Collins speculum. During the physical examination, the vaginal pH will be measured by allowing 1 min of direct contact between pH strips (4.0-7.0; Merck, Darmstadt, Germany) and the vaginal wall. For vaginal microbiota evaluation, vaginal smears will be collected with a swab and the microbiota pattern will be classified according to Nugent et al. (1991), Cybley & Cybley (1991) and Donders et al. (2002) criteria and to detect the presence of Candida spp. morphotypes. Whiff test will be performed by placing a drop of 10 % KOH (v/v) on a swab with vaginal content. Results will be then expressed as negative, doubtful and positive (whiff test). Endocervical samples will be collected with cytobrush for molecular analysis of infection by Human Papillomavirus, Chlamydia trachomatis and Neisseria gonorrhoeae. Additional sample with representation of squamous and glandular epithelium will be collected for oncotic cytology. Finally, a sample from the bottom of the posterior vaginal sac will be collected with Ayre's spatula for research of Trichomonas vaginalis in Diamond's Medium. At each longitudinal follow-up visit, vaginal samples will be collected for the microbiota pattern. In first and third longitudinal follow-up visit, endocervical and posterior vaginal sac samples will be collected for sexually transmitted infections diagnoses. The data obtained in the study will be analyzed by appropriate statistical tests respecting the assumptions determined by the results. The significance level adopted for the tests will be 5%.