Diagnostics · Tests we don't routinely offer
NK Cell Testing
Natural killer (NK) cell testing is offered by some clinics after recurrent miscarriage or unsuccessful IVF. Here's what it claims to measure, what the evidence says, and what we'd suggest looking at instead.
At a glance
Not recommended outside researchNot offered by
Truth Fertility
Had this test elsewhere? We can look at your results.
What is NK cell testing?
NK cells are part of the immune system. They're found in the blood and in the lining of the womb, where they play a normal role in early pregnancy.
NK cell tests measure the number or activity of these cells, either in a blood sample or a biopsy of the womb lining. The idea is that too many, or overactive, NK cells might interfere with implantation or early pregnancy. Some clinics then offer immune treatments, such as steroids or intralipid infusions, based on the results.
What the evidence says
Why guidelines don't recommend it
NK cells in the blood don't reliably reflect what's happening in the womb, and there's no agreed normal range. Guidelines from ESHRE and the RCOG don't recommend NK cell testing outside research, and the treatments offered on the back of results haven't been shown to improve live birth rates in good-quality trials.
In short
- 1No agreed normal range
- 2Blood levels don't reflect the womb lining
- 3Treatments not shown to improve live birth rates
- 4Some treatments have side effects
What we'd suggest looking at instead
After recurrent miscarriage or unsuccessful IVF, these investigations are more likely to be useful. You may not need all of them.
- In guidelines
- Situational
- Antiphospholipid antibodiesVia consultationIn guidelines
One of the few well-established, treatable causes of recurrent miscarriage.
Via consultationBlood test - Thyroid function and antibodiesVia consultationIn guidelinesAbout this test →
Thyroid problems are common, simple to test for and usually treatable.
- Sperm DNA fragmentationfrom £545SituationalAbout this test →
Sperm DNA damage isn't seen on a standard semen analysis, and some studies link it with miscarriage and failed implantation.
- Karyotype (chromosome) testing£399 per personSituationalAbout this test →
Checks both partners for chromosomal rearrangements that can affect pregnancies.
Common questions
I've already had NK cell testing. What now?
You're welcome to bring your results to a consultation or a Check with Verity First review. We'll look at them alongside everything else you've had done, and help you work out which next steps are most likely to be useful.
Should I have immune treatment?
That's a decision to make with a specialist. The evidence for immune treatments such as steroids and intralipid infusions is weak, and they can have side effects, so it's worth understanding the pros and cons before starting any.
Talk it through with us
If you're weighing up NK cell testing or immune treatment, a case review can help you decide what's worth investigating.
Advanced Fertility Case Review
£24090 mins. A detailed review of your history and investigations, including any tests you've had elsewhere.
Not sure where to start?
Check with Verity First
£35Send a short account of your journey and your existing results, and Verity will suggest the most useful next step. It's a brief review rather than a full treatment plan, and the £35 can be credited towards a later consultation or acupuncture appointment.