Natural Killer Cells and Miscarriage ; The Immune factor behind unexplained Pregnancy loss

If you have had recurrent miscarriage and every standard test has come back normal this post may be the one that finally gives you an answer.

Because there is a category of immune dysfunction that is present in a significant proportion of women with unexplained recurrent miscarriage  one that is not tested in standard investigation, is not widely known outside specialist reproductive immunology, and yet has a growing body of evidence behind both its role in pregnancy loss and its treatment.

It involves a type of immune cell called natural killer cells.

And understanding them may change everything about how you approach your next pregnancy.

WHAT ARE NATURAL KILLER CELLS?

Natural killer cells commonly called  NK cells are a type of white blood cell that forms part of the innate immune system. They are so named because of their original characterisation as cells that could kill tumour cells and virus-infected cells without prior sensitisation  unlike T cells and B cells, which require prior exposure to an antigen before mounting a response.

NK cells are found throughout the body. But the NK cells that matter most in the context of miscarriage are a specialised population found in the uterus  called uterine natural killer cells, or uNK cells.

Uterine NK cells are not the same as peripheral blood NK cells  the ones circulating in your bloodstream. They are a distinct population, found specifically in the endometrium, with a unique profile of surface receptors and a very different function from their peripheral counterparts.

And their function in pregnancy is not to attack. It is to facilitate.

Homocysteine and Miscarriage.

If you have experienced miscarriage  one, two, or more you have probably been told one of two things.

Either a cause was found and treatment was offered.

Or no cause was found and you were told to try again.

If you were in the second group if you were handed the diagnosis of unexplained recurrent miscarriage and sent home to wait  I want to tell you about a marker that is almost never tested in this context.

It is called homocysteine.

And the research connecting elevated homocysteine to miscarriage, implantation failure, and early pregnancy loss is both extensive and largely ignored in mainstream fertility medicine.

This post is for every woman who has been told there is nothing to find.

WHAT IS HOMOCYSTEINE?

Homocysteine is an amino acid, a building block of protein  that is produced naturally in the body as a byproduct of metabolising methionine, an essential amino acid found in meat, eggs, and dairy.