Natural killer cells (NK cells) form part of the body’s immune system. They help the body fight infection and cancer. Every organ has NK cells to protect it, including the uterus (womb).
NK cells in the uterus are known as uNK cells. They play an important role in helping the body become pregnant.
In order to become pregnant, the womb lining needs to inflame slightly so the embryo can attach (or implant) to the uterine wall. uNK cells contribute to this process of inflammation. If there are too many or too few uNK cells, this can cause too much or not enough inflammation, which are both associated with infertility and miscarriage.
uNK cells also help blood vessels to develop, which make sure that the baby gets a good supply of oxygen and nutrients during pregnancy.
It is possible to have tests to measure your level of NK cells. If you do decide to go ahead with tests or treatment, please be aware that the treatment is still considered experimental. Although there is a series of scientific studies that find that NK cells are important for normal pregnancy, it’s still not clear what the optimal level of uNK cells is and what is the best way to correct any imbalance. This is still yet to be tested in large scale studies.