Improving Menstrual and VAginal Health for All

NCT06646185 | Recruiting

• 1 other identifier: 2023-30
• Study Type: interventional
• Target: 100
• Locations: 3 countries
• Sites: 3

Brief Summary

A three-period crossover trial will study the effects of short-term use of 3 menstrual products (menstrual pad, tampon, menstrual cup) on the bacterial composition of the vaginal microbiome in three countries (Peru, Cameroon, and Switzerland). Each crossover period consists of two menstrual cycles, thus resulting in a 6-month trial. Participants will be randomly assigned to one of 6 exposure sequences (different order of products per sequence); in each sequence, participants will adopt each menstrual product for 2 menstrual cycles. Participants will provide vaginal microbiome samples via self-sample swabs at 3 points during each menstrual cycle. Given the crossover design of the study, there is not a dedicated control group.

Conditions

Effects of Menstrual Products on the Vaginal Microbiome

Keywords

vaginal microbiome; menstruation; crossover study; menstrual products

Outcome Measures

Primary Outcomes (1)

• Log-ratio of Dialister to Lactobacillus crispatus relative abundances in vaginal swabs (continuous variable)

  The abundances of each bacterial taxa are estimated from the DNA amplification and sequencing of amplicons from the 16S rRNA gene.

  Monthly, after menstruation ends, through study completion, an average of 6 months.

Secondary Outcomes (11)

• Log-ratio of Bifidobacterium vaginalis to Lactobacillus relative abundances in vaginal swabs (continuous variable)

  Monthly, after menstruation ends, through study completion, an average of 6 months.

• Log-ratio of Prevotella to Lactobacillus relative abundances in vaginal swabs (continuous variable)

  Monthly, after menstruation ends, through study completion, an average of 6 months.

• Dominant taxon in vaginal swabs (categorical variable)

  Monthly, after menstruation ends, through study completion, an average of 6 months.

• Community state type in vaginal swabs (categorical variable)

  Monthly, after menstruation ends, through study completion, an average of 6 months.

• Total bacterial load in vaginal swabs (continuous variable)

  Monthly, after menstruation ends, through study completion, an average of 6 months.

Study Arms (6)

TamponCupPad

OTHER

Participants will adopt tampons during the first two menstrual cycles (first period of the trial), followed by adoption of cups during the next two menstrual cycles (second period), and lastly menstrual pads for the next two menstrual cycles (third crossover period).

Other: Menstrual Pads; Other: Menstrual Cups; Other: Tampons

TamponPadCup

OTHER

Participants will adopt tampons during the first two menstrual cycles (first period of the trial), followed by adoption of pads during the next two menstrual cycles (second period), and lastly menstrual cups for the next two menstrual cycles (third crossover period).

Other: Menstrual Pads; Other: Menstrual Cups; Other: Tampons

CupTamponPad

OTHER

Participants will adopt menstrual cups during the first two menstrual cycles (first period of the trial), followed by adoption of tampons during the next two menstrual cycles (second period), and lastly menstrual pads for the next two menstrual cycles (third crossover period).

Other: Menstrual Pads; Other: Menstrual Cups; Other: Tampons

CupPadTampon

OTHER

Participants will adopt menstrual cups during the first two menstrual cycles (first period of the trial), followed by adoption of menstrual pads during the next two menstrual cycles (second period), and lastly tampons for the next two menstrual cycles (third crossover period).

Other: Menstrual Pads; Other: Menstrual Cups; Other: Tampons

PadTamponCup

OTHER

Participants will adopt menstrual pads during the first two menstrual cycles (first period of the trial), followed by adoption of tampons during the next two menstrual cycles (second period), and lastly menstrual cups for the next two menstrual cycles (third crossover period).

Other: Menstrual Pads; Other: Menstrual Cups; Other: Tampons

PadCupTampon

OTHER

Participants will adopt menstrual pads during the first two menstrual cycles (first period of the trial), followed by adoption of menstrual cups during the next two menstrual cycles (second period), and lastly tampons for the next two menstrual cycles (third crossover period).

Other: Menstrual Pads; Other: Menstrual Cups; Other: Tampons

Interventions

Menstrual Pads OTHER

Participants adopt menstrual pads to manage their menstruation during 2 menstrual cycles. For each menstrual cycle, participants will provide vaginal microbiome samples via self-sampled swabs at 3 points.

CupPadTampon; CupTamponPad; PadCupTampon; PadTamponCup; TamponCupPad; TamponPadCup

Menstrual Cups OTHER

Participants adopt menstrual cups to manage their menstruation during 2 menstrual cycles. For each menstrual cycle, participants will provide vaginal microbiome samples via self-sampled swabs at 3 points.

CupPadTampon; CupTamponPad; PadCupTampon; PadTamponCup; TamponCupPad; TamponPadCup

Tampons OTHER

Participants adopt tampons to manage their menstruation during 2 menstrual cycles. For each menstrual cycle, participants will provide vaginal microbiome samples via self-sampled swabs at 3 points.

CupPadTampon; CupTamponPad; PadCupTampon; PadTamponCup; TamponCupPad; TamponPadCup

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• able to provide informed consent;
• aged 18-35;
• residing in the recruitment region and expecting to reside in the same region for at least six months following recruitment (Yaoundé/ Gounougou, Cameroon; Loreto/Lima/Maynas provinces, Peru; or Basel-Landschaft and Basel-Stadt cantons, Switzerland);
• are native speakers or are able to read and understand one of the following languages in each respective country (German, French, Italian, English or Spanish in Switzerland; French or English in Cameroon; Spanish in Peru);
• had menstrual cycles of 21-35 days for at least the last 4 months;
• had menses which lasted at least 3 days for at least the last 4 months.

You may not qualify if:

• experienced a menstrual abnormality with any of the menstrual cycles in the last 4 months (such as oligomenorrhea or amenorrhea, or bleed more than 7 days a month);
• are pregnant or actively trying to become pregnant;
• are breastfeeding;
• used antibiotics and/or vaginal antifungals in the last 30 days prior to recruitment;
• had a vaginal birth in the last 6 months;
• vaginal surgery, perineal surgery, uterine surgery, miscarriage or abortion in the last 6 months;
• history of Toxic Shock Syndrome ;
• positive to detection of the toxic shock syndrome toxin-1 gen (tst) using Polymerase Chain Reaction (PCR);
• Intrauterine device in situ;
• under medication (treatment against infectious or chronic disease) at the time of recruitment or during the 3 weeks prior to recruitment;
• clinical symptoms of vaginal infection;
• smoker.

Sponsors & Collaborators

• Swiss Tropical & Public Health Institute: lead
• Universidad Nacional de la Amazonia Peruana: collaborator
• Universidad Peruana Cayetano Heredia: collaborator
• Centre de Recherche sur les Maladies Emergentes et Re-Emergentes: collaborator
• Universiteit Antwerpen: collaborator

Study Sites (3)

Centre de Recherche sur les Maladies Emergentes et Re-Emergentes

Yaoundé, Yaoundé, 3, Cameroon

RECRUITING

Universidad Nacional de la Amazonia Peruana

Iquitos, Iquitos, 16007, Peru

RECRUITING

Swiss Tropical and Public Health Institute

Allschwil, Allschwil, 4123, Switzerland

RECRUITING

Related Publications (1)

• Ticlla MR, Dumbaugh M, Condori-Catachura S, Kenfack J, Hattendorf J, Van Der Donck L, Arista KM, Arora N, Gebert S, Ackermann L, Ahannach S, Riveros M, Blas MM, Kenmoe S, Barriere FY, Shea AA, Pinedo-Cancino V, Rivas-Ruiz R, Di Cecco V, Esemu L, Ochoa TJ, Lebeer S, Martin Hilber A, Merten S. Improving menstrual and vaginal health for all (IMVAHA): protocol for a randomised cross-over trial assessing the impact of menstrual products on the vaginal microbiome of women aged 18-35 years in Cameroon, Peru and Switzerland. BMJ Open. 2026 Apr 22;16(4):e108568. doi: 10.1136/bmjopen-2025-108568.

  PMID: 42020126 DERIVED

MeSH Terms

Interventions

Menstrual Hygiene Products

Intervention Hierarchy (Ancestors)

Feminine Hygiene Products; Equipment and Supplies

Study Officials

• Sonja Merten, PhD

  Swiss Tropical & Public Health Institute

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Sonja Merten, MD MPH PhD

CONTACT

0041-61-284-8387; sonja.merten@swisstph.ch

Monica Ticlla, PhD

CONTACT

0041-61-284-8387; monicaroxana.ticllaccenhua@swisstph.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Head of Unit Society, Gender and Health

Model Details: A three-period crossover trial will study the effects of short-term use of 3 menstrual products (menstrual pad, tampon, menstrual cup) on the bacterial composition of the vaginal microbiome in three countries (Peru, Cameroon, and Switzerland). Each crossover period consists of two menstrual cycles, thus resulting in a 6-month trial. Participants will be randomly assigned to one of 6 exposure sequences (different order of products per sequence); in each sequence, participants will adopt each menstrual product for 2 menstrual cycles. Participants will provide vaginal microbiome samples via self-sample swabs at 3 points during each menstrual cycle. Given the crossover design of the study, there is not a dedicated control group. No wash-out period is included because participants can not stop the use of menstrual products to manage their menstruation.

Study Record Dates

• First Submitted: September 24, 2024
• First Posted: October 17, 2024
• Study Start: April 15, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: April 23, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CH (1); CA (1); PE (1)