Dealing with natural killer cells while trying to get pregnant?  As you know this can be controversial…

About 3 years ago I wrote about an autoimmune issue that could explain some “unexplained” fertility issues and when addressed could help some couples become pregnant.

This is also coming to the forefront when dealing with not only unexplained fertility issues, but recurrent miscarriage and in IVF why some good embryos just don’t seem to implant.

Scientists at a New York Medical centre have found, though only on a small scale and larger studies need to be performed, is if you think you are fertilizing and not holding you may be experiencing an autoimmune issue.

How Do Natural Killer Cells Relate to Fertility and Miscarriage?

Natural Killer cells are cells in our bodies that we need to get rid of structures that could otherwise cause problems in the body, i.e. tumors, cancers, etc. However when these NKC are at increased levels in the uterine lining or endometrium,(and there is controversy over what increased is because they numbers differ significantly in different parts of the cycle) they might be actually mistaking the embryo for a foreign body and attacking it, not allowing it to implant. However more needs to be learned about the NKC in the uterine lining because it does appear to be different than the NKC in other parts of the body, and therefore what actually happens is unknown and maybe much more complex or simplified than what researchers now surmise.

If however elevated levels of NKC do create issues for fertility it may still be hard to understand why your own body may be attacking its own tissue, i.e. the fertilized egg.

Remember, the immune system’s response is meant to get rid of foreign invaders in your system to keep you healthy. If your body looks at the fertilized egg as a foreign invader then it may try to get rid of it. In some cases because the fetus wouldn’t have survived or it has a chromosomal defect the body will get rid of the pregnancy for this reason.

Elevated Natural Killer Cells in the endometrial lining may be an issue for you if you have had recurrent miscarriages or many missed conceptions (fertilizations that just don’t seem to take), or several IVF attempts where you seem to produce good quality embryos but they just don’t attach.

To test this theory some physicians are doing biopsies of the endometrial lining to assess NKC activity. If elevated then medicine can be administered either with an artificial cycle or right when a natural pregnancy is detected to suppress the activity of the NKC long enough for the embryo to implant.

I have found that not all doctors know about this and many that do know about it are skeptical that it is even an issue and are resistant to look into it. 

I would still talk to your fertility specialist about this issue to see what their thoughts are if you have had several IVF cycles with good embryos but no implantation, recurrent miscarriages or long cycles where your temps are elevated past the normal 14 day luteal phase but then drop out and you begin menstruating 16, 17, 18 days post ovulation.

If they do the testing and it turn out to show elevated levels or Natural Killer Cells in the uterine lining, as I referred to earlier medically they can do some things to address the issue, but naturally you may be able to assist as well.

Keep in mind though if NKC are tested from the uterine lining that research has shown that at certain times of the cycle, the NKCs are normally elevated.  So if you have a positive test or a test that says the Natural Killer Cells are elevated, make sure you discuss this with your doctor to confirm that at when you had the test done, this wasn’t at the time that NKCs are normally increased in the uterus OR that if done at that time, your results are higher than what they should be for that time in the cycle.  Because if they are looking at levels typically normal for the first half of the cycle but you were tested in the second half this can create some confusion as to whether or not your test results were truly elevated.

Can Progesterone Help With NKC Activity?

Progesterone has been considered nature’s own immunosuppressant for years. Meaning if there is enough progesterone available there ‘the NKC activity may not be an issue.  (See a research article here)

If this is the case, that would then bring us back to the thyroid and adrenals since T3 a thyroid hormone and cortisol, your stress hormone, directly impact progesterone production.

Studies have shown that fish oil is beneficial to help address autoimmune issues. We recommend fish oil that has gone thru the procedure to remove as much mercury as possible. 

Vitamin E is also an excellent choice but should always be taken in synergy with other supplements to create the best effect for the body.

Probiotics For Uterine Health

Recent research has shown that despite what researchers used to think, the uterus is not a sterile environment, meaning there are microbes present that make up a uterine microbiome.   You often hear about this related to the gut but many areas of the body has its own microbiome.  The gut, the skin, the vagina, the uterus, etc.  

So there is potential that if the uterine microbiome has an imbalance between good and bad bacteria there may be a reaction from the bodies Natural Killer Cells making them respond to the imbalance and therefore increasing NKC’s activity.  More research needs to be done in this area.  But a multi-strain probiotic taken orally has many other benefits if it is accompanied by a healthy eating plan, that it would be a great addition to your supplementation regime.  

Probiotics inserted vaginally may also be a benefit however the research there does support utilizing certain strains of probiotics vaginally for bacterial vaginosis  (study here) so there is certainly promise to their use for uterine health as well.