What is Endometrial NK testing?

Everyone wishes to improve their chances of IVF or ICSI success and it is known that the lining of the women (endometrium) is important in helping the embryo implant. The way the endometrium supports implantation is poorly understood. However, research suggests the immune cells such as Natural Killer Cells (NK cells) may have and impact on the ability to conceive as well as the ability to maintain a pregnancy. As such, testing for NK cells may help identify women at high risk of reproductive failure such as infertility or miscarriage who may benefit from treatment.

Furthermore, new research suggests that the presence of infection or inflammation within the lining of the womb can reduce implantation and increase the risk of miscarriage. This can be tested for looking for plasma cell CD138 within the lining of the womb

Who should consider have Endometrial biopsy testing?

Immune testing and treatment is not required nor appropriate for most patients, therefore is currently undertaken on an experimental basis. However, those with recurrent IVF failure or recurrent miscarriage where no other cause is found, it may help improve your chances of success.

It is important to stress at this stage that whilst research evidence points to a link between reproductive failure and increased NK cells, there is yet more research to do to prove a definite link as well as confirm what treatment would be of benefit.

If inflammation or an infection is found, there is reasonable evidence that treatment with anitbiotics could be beneficial. https://pubmed.ncbi.nlm.nih.gov/29908776/

How is the Endometrial biopsy test performed?

This is similar to a cervical smear test, however because a fine tube is placed into the womb some women experience discomfort.

A speculum is gently inserted into the vagina to allow the clinician to see the cervix. The cervix is cleaned before inserting the plastic Pipelle tube through the cervix. The endometrial lining is sampled by moving the catheter up and down, this can cause period type pain. As no anaesthesia is required you will be able to go straight home/ work after the procedure.

When is Endometrial sampling or biopsy performed?

NK levels vary depending on the time a sample is taken, it is important to get the timing right. We recommend you do daily urine dipstick tests beginning a few days before you expect ovulation to occur. Once you have a positive ovulation test please email: nurses@bcrm.org.uk and we will arrange for the test to occur 6-9 days later.

What happens to the sample?

The sample will be sent to the laboratory for special testing where the NK cells CD56 as well as plasma cells CD138 are measured. A result is usually available within 2-3 weeks

Preparing for your Endometrial sampling procedure:

Please make sure you do a home pregnancy test before attending for your appointment, as doing the procedure may interfere with the embryo if you are pregnant. It is advisable to avoid conceiving the cycle your are having the test done

You may wish to bring a sanitary towel with you for after the procedure as it is common to experience some light spotting afterwards. It would be a good idea to take paracetamol and ibuprofen 1-2 hours before the procedure to help prevent discomfort.

Are there any risks associated with taking the womb lining biopsy?

The procedure in some case can be uncomfortable particularly if the opening to your womb is tightly closed (stenosed) or if the entry to your womb lies at an awkward angle.

Occasionally one may feel faint after the procedure and very rarely there is a risk of infection.

After the procedure:

After the procedure, we recommend you wear sanitary protection; you should be able to drive and resume normal daily activities as well as eat & drink normally. If you experience any problems please get in touch with us.