Uterine Natural Killer (uNK) cell testing in IVF: unnecessary, unproven and misleading
Dr. Malpani Exposes the Uselessness of uNK Cell Testing in IVF
Patient: Dr. Malpani, my IVF doctor, recommended a test for uterine natural killer (uNK) cells. He said it could explain my failed embryo transfers. Should I get it done?
Dr. Malpani: I wouldn’t waste your time or money on it. uNK cell testing is one of those expensive but scientifically questionable tests that IVF clinics push to make patients feel like they’re getting personalised treatment. The reality? It’s useless for improving IVF outcomes.
Patient: But aren’t uNK cells important for implantation and pregnancy?
Dr. Malpani: uNK cells do play a role in early pregnancy, but here’s the catch—having a higher or lower count doesn’t necessarily mean anything is wrong. These cells fluctuate naturally throughout the menstrual cycle, and no one even knows what an "ideal" number should be.
Patient: My doctor said that elevated uNK cells might be why my embryos aren’t implanting. Could that be true?
Dr. Malpani: That’s just speculation, not proven science. Some studies suggest a possible link between high uNK cell levels and implantation failure, but there’s no clear evidence that these cells cause IVF failure. Many fertile women have high uNK cells and conceive without any issues.
Patient: Then why do some doctors still push this test?
Dr. Malpani: Because it’s an easy way to make money off anxious IVF patients. When doctors tell you that a test might “explain” your failure, you feel like you’re finally getting an answer. But in reality, the test does nothing to fix the problem. It just creates unnecessary anxiety and opens the door to more expensive, unproven treatments.
Patient: My report says my uNK cell count is 12%, which is “within normal range.” Does that mean everything is fine?
Dr. Malpani: That’s the irony! Even if your results are normal, they don’t tell you anything useful. The reference ranges vary from lab to lab; there’s no consensus on what’s “too high” or “too low,” and even if your levels were different, there’s no agreed-upon treatment to “fix” them.
Patient: What about treatments like steroids or intralipid infusions for high uNK cell levels?
Dr. Malpani: That’s another scam. Some clinics prescribe immunosuppressive treatments to “calm down” uNK cells, but there’s no solid evidence that these drugs improve IVF success rates. In fact, a 2018 Cochrane review found that immune-modulating treatments don’t have enough scientific backing to be recommended.
Patient: If uNK testing is so unreliable, why isn’t this widely known?
Dr. Malpani: Because the IVF industry thrives on hope marketing. When patients keep failing cycles, they desperately look for explanations, and clinics are happy to sell them expensive, unproven tests that make them feel like they’re getting closer to an answer—even when they aren’t.
Patient: So, should I just ignore this test and focus on my IVF treatment?
Dr. Malpani: Absolutely. Instead of wasting time on junk science, focus on the real factors that affect IVF success—high-quality embryos, a good lab, and a competent doctor who doesn’t push unnecessary tests. IVF is already expensive; don’t let them scam you into paying for tests that won’t help.
Patient: That makes me feel a lot more empowered. Thank you, Dr. Malpani.
Summary
Many IVF clinics recommend uNK cell testing as a way to explain recurrent implantation failure, but Dr. Malpani debunks this as a useless and misleading test. While uNK cells play a role in pregnancy, testing them provides no actionable insights because
- uNK levels fluctuate naturally, and there’s no universally agreed-upon normal range.
- Studies linking high uNK cells to implantation failure are correlational, not causal—many fertile women also have elevated levels.
- Even if a patient has high uNK cells, there’s no proven treatment to correct it. Steroids and intralipid infusions are often prescribed despite weak scientific backing.
- Major fertility organisations like ASRM and ESHRE do not recommend this test because of its lack of clinical utility.