Q: What is the PRELI test?
Xambika’s PRELI test examines the health of your womb lining (endometrium) by measuring how well it prepares for pregnancy each cycle. It looks at the key biological process (decidual reaction) that helps an embryo implant and develop the endometrium to support a full-term pregnancy. In addition, the test also looks at molecular timing, immune readiness, and progesterone responsiveness of the womb lining.
Q: Why is the womb lining so important?
A healthy womb lining is essential for allowing the embryo to implant, helping the placenta grow and supporting the pregnancy. Recent research shows that problems in this process can cause miscarriage or failed implantation, even when the embryo is healthy.
Q: What can the PRELI test tell me?
PRELI test results may indicate that your womb lining is:
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Well-balanced and appropriately timed, or not.
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Preparing too quickly (resistant to embryo implantation) or too slowly (prone to breaking down in early pregnancy).
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Showing signs of immune imbalance.
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Adequately responsive to progesterone or not
Your doctor will discuss what the findings mean for you and whether treatment adjustments may help.
Q: Who is the PRELI test for?
PRELI is intended for women of reproductive age who have experienced miscarriage, implantation failure (e.g., IVF not working despite good-quality embryos), or unexplained infertility.
Q: What happens during the PRELI test?
The PRELI test involves a small biopsy of the womb lining, taken by your healthcare professional at a specific time in your cycle. The sample is analysed in a specialised laboratory using advanced molecular techniques. The results are shared with your clinician, who will discuss what they may mean for your care and possible next steps. Your clinic will guide you through the timing, procedure, and any questions you may have.
Q: Is it painful?
Most people tolerate the procedure well, but you may experience:
- Period-like cramping during the procedure
- Light spotting or mild bleeding for 1–2 days afterwards
The biopsy takes around 10–20 seconds.
Q: When in my cycle is the sample taken?
6-10 days after a positive ovulation test (peak day) in a natural cycle or a modified natural cycle with progesterone support, or 6-10 days after starting progesterone in an artificial/medicated cycle.
Q: Will I get treatment after the PRELI test?
Based on the test results, your doctor might suggest a treatment or intervention, such as medication to strengthen the lining, adjust inflammation or personalised progesterone support.
The goal is to help you enter your next attempt at pregnancy under the best possible conditions for success.
Q: Will the PRELI test delay my fertility treatment?
No. It is usually completed in one cycle and helps avoid repeated unsuccessful attempts.
Q: Is this the same as other tests I may have heard of?
No. While most existing fertility tests each look at a single component of the endometrium (timing, microbiome, or immune activity), none of them measures the process that matters most. PRELI is the only test that accurately measures the dynamic decidual reaction, the critical inflammatory transformation that allows embryos to implant and pregnancies to progress. Combined with insights on molecular timing, immune readiness and progesterone responsiveness of the womb lining, the test delivers a uniquely comprehensive view that supports precise, personalised intervention.
Q: Can the PRELI test explain my miscarriages?
Yes. Research shows that many miscarriages are linked to a womb lining that does not prepare properly—even when embryos are healthy. The PRELI test helps identify whether this applies to you.
Q: How accurate is the PRELI test?
Xambika’s PRELI test is based on over 20 years of research and one of the world’s largest studies on miscarriage and womb lining health by Professor Brosens and his team.
Q: Does the PRELI test guarantee a successful pregnancy?
No test can guarantee success, but the PRELI test gives you and your doctor detailed insights into the endometrium, which can help inform a personalised treatment plan for the next steps in your fertility journey if the endometrium played a role in your miscarriage or implantation failure.
Q: How long will results take?
Results are usually available for your doctor within ten working days after your biopsy reaches our laboratory. Your doctor will review the results with you and discuss next steps.
Q: Can I use the PRELI test if I’m not doing IVF?
Yes. You can also use it before natural conception attempts.
Q: Where can I get the PRELI test?
The PRELI® test is expected to launch in the UK (excluding Northern Ireland) around July 2026 through selected fertility clinics and specialists. On our website, you can find partner clinics that offer the test.
If your clinic is not yet listed, you can simply discuss it with your healthcare provider. Most clinics can order the test directly from Xambika. You may also choose to contact one of our existing partner clinics.
