HHV-6A uterine screening for complex infertility

• HHV-6A is a herpesvirus that can infect endometrial tissue.
• Detected in endometrium from some women with recurrent implantation failure or primary unexplained infertility, and not in endometrium from fertile controls.
• Associated with altered local immune signalling and reduced endometrial receptivity in some patients.
• Small series suggest HHV-6A-positive women treated with antivirals may show higher implantation and pregnancy rates than untreated HHV-6A-positive patients.

Screening focus

• Adjunctive screen for HHV-6A DNA in material from the uterine environment.
• Used in complex cases: unexplained infertility, recurrent loss, repeated IVF failure.

Sample & assay

• Sample: 1–2 mL menstrual fluid collected at home during normal flow days.
• Source: menstrual fluid contains endometrial cells and secretions from across the uterine lining.
• Method: quantitative PCR (qPCR) targeting HHV-6A DNA.
• Typing: distinguishes HHV-6A from HHV-6B.
• Output: positive/negative plus quantitative viral load for follow-up after treatment.

Which patients

• Unexplained infertility after basic work-up.
• Recurrent pregnancy loss without a clear cause.
• Repeated embryo implantation failure with good-quality embryos and lining.
• Patients at the stage of testing to understand why they are not conceiving or carrying.

How to use the result

• Positive: HHV-6A DNA detected. In the right context, may support considering antiviral or related management as part of your broader plan. Quantitative results can follow change in viral load after treatment.
• Negative: HHV-6A DNA not detected at the time of sampling. HHV-6A is less likely to be a major driver of this patient’s implantation failure now, allowing focus on other causes.

1) What is the chance of a false positive or false negative?

The assay is a qPCR designed to detect HHV-6A DNA and to differentiate HHV-6A from HHV-6B. Menstrual fluid provides a broad sample of endometrial cells and secretions, which helps reduce sampling error compared with a focal biopsy. Analytical false positives are expected to be rare; false negatives are also expected to be uncommon, though timing and sample quality still matter as with any PCR.

2) How accurate is menstrual-fluid–based testing?

Menstrual fluid reflects the whole uterine lining, not one biopsy site. The coVee™ assay uses high-sensitivity qPCR for HHV-6A with typing for HHV-6A vs HHV-6B. Internal validation has shown high analytical sensitivity and specificity.

3) How many times should a patient be tested?

A negative result during an active struggle to conceive makes HHV-6A less likely to be active at that time. As a herpesvirus, HHV-6A can remain latent and reactivate; retesting can be considered if new, unexplained difficulty conceiving appears (for example, secondary infertility). For HHV-6A–positive patients who undergo treatment, a follow-up coVee™ test can assess change in viral load and support timing of subsequent cycles.

4) What type of testing is performed?

Molecular testing via quantitative PCR (qPCR) on menstrual-fluid–derived uterine material. The assay is designed to detect HHV-6A DNA at low copy number and to differentiate HHV-6A from HHV-6B.

5) Why coVee™ vs endometrial biopsy?

coVee™ is non-invasive and uses a broad sample of the uterine lining. It can distinguish HHV-6A from HHV-6B and provides quantitative viral load for monitoring. For patients, it avoids a procedure room, anesthesia, and recovery, and is typically less expensive than a hospital-based biopsy. Biopsy remains important when broader histology or other pathology is suspected; coVee™ is a focused HHV-6A screen.

If you would like to discuss HHV-6A screening or a de-identified case in more detail, you can request a brief call with our clinical liaison team.

Please contact us via the form on our contact page or email info@fertilityphoenix.com and let us know you are a clinician with an HHV-6A question.