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.

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.

Inclusion Criteria:

• Age 18-44 years
• Patients whose written informed consent 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
• BMI between 18.5-35 kg/m2 (both included)
• Must be able to understand and read the informed consent form in English.

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 contraceptive pills in the past month
• Latex or silicone allergy (Diva Cup and Vaginal Disc)

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