ClinicalTrials.gg
CompletedNCT05150639Updated Mar 2, 2026

Vaginal Microbiome and IVF Pregnancy Outcome

An observational study in Vaginal Flora Imbalance, sponsored by Freya Biosciences ApS. Completed at 1 site in United States. Open to female participants aged 18 Years to 44 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-03-02.

Sponsored by Freya Biosciences ApS · Observational

Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
301
Ages
18 Years to 44 Years
Sex
Female
01

Study summary

The aim of this prospective, observational study is to investigate the prevalence of vaginal dysbiosis among women undergoing IVF procedures in the US. And to investigate the associations between the vaginal microbiome and the pregnancy outcome following IVF.

Read the detailed description

The present study will evaluate differences in vaginal microbiome composition in pregnant and non pregnant women who have undergone IVF treatment with frozen embryo transfer. Concurrently we aim to identify whether menstrual tissue and Cervicovaginal secretion possess complimentary biomarker information reflecting the immune/inflammatory status of the reproductive tract to determine its impact on pregnancy success following frozen embryo transfer IVF procedure.

02

Conditions studied

  • Vaginal Flora Imbalance
03

In context

Lead sponsor

Freya Biosciences ApS is the lead sponsor of 5 studies on the registry; 2 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 44 Years
Sexes eligible
Female
Accepts healthy volunteers
Yes
Sampling method
Probability sample

Study population

Women planning to undergo frozen embryo transfer IVF treatment at Boston IVF fertility clinic in Boston, US.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Age 18-44 years
  • Patients whose written approved by the Institutional Review Board (IRB) has been obtained, after having been duly informed of the nature of the study and voluntarily accepted to participate after being fully aware of the potential risks, benefits and any discomfort involved.
  • Women undergoing a planned frozen embryo transfer
  • between 18.5-35 kg/m2 (both included)
  • Must be able to understand and read the informed consent form in English.

Exclusion criteria

Exclusion Criteria:

  • Current diagnosis of pathologies or malformations that affect the uterine cavity such as polyps, intramural myoma, adhesions, fibroids or hydrosalpinx.
  • Any illness or medical condition that is unstable or which, according to medical criteria and Investigator's discretion may put at risk the patient's safety and her compliance in the study.
  • Participants currently taking antibiotics or with any known condition requiring regular use of antibiotics, that would suggest the participant is likely to need antibiotic treatment during the observational period of this study.
  • Systemic and/or vaginally applied antibiotic use within the last month prior to screening (except for prophylactic antibiotics related to egg retrieval).
  • Patients utilizing oral pills in the past month
  • Latex or silicone allergy (Diva Cup and Vaginal Disc)
Terms in these criteria, in plain language(3)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
301 participants (actual)
Patient registry
No
Biospecimen retention
Samples without dna

Interventions

  • OtherIVF

    Women planning to undergo frozen embryo transfer IVF procedure will be included. Samples will be obtained, but no study intervention will be applied. Pregnancy outcome data will be obtained, following frozen embryo transfer, to correlate against other data from samples (vaginal microbiome etc).

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What researchers measure

Primary outcomes

  1. Prevalence of vaginal dysbiosis

    The prevalence (evaluated as % of included population) of vaginal dysbiosis in women undergoing frozen embryo transfer IVF treatment in the US

    Time frame: Evaluated from sample collected 1 week prior to frozen embryo transfer

Secondary outcomes

  1. Associations of microbiome

    The difference in pregnancy success rates (biochemical pregnancy, clinical pregnancy and live birth) following frozen embryo transfer in women with versus without vaginal dysbiosis

    Time frame: Evaluated from sample collected 1 week prior to frozen embryo transfer and correlated with pregnancy outcomes obtained up until birth

07

Study locations

1 site
  • Boston IVF The Waltham Center
    Waltham, Massachusetts 02451, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Ran from Mar 2022 to primary completion in May 2023, 14 months.

How these figures are worked out, and which studies are left out of them.

Registered
Nov 26, 2021
First posted
Dec 9, 2021
StartActual
Mar 18, 2022
Primary completionActual
May 26, 2023
CompletionActual
May 26, 2023
Last update
Mar 2, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Mar 2, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05150639
Lead sponsor
Freya Biosciences ApS
Collaborators
Boston IVF
Responsible party
Sponsor
First posted
Dec 9, 2021
Start date
Mar 18, 2022
Primary completion
May 26, 2023
Completion
May 26, 2023
Last update
Mar 2, 2026

Study contacts

Denis Vaughan, PhD
principal investigator · Boston IVF
Denny Sakkas, PhD
principal investigator · Boston IVF

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.

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