NK cells (Natural Killer cells) are specialized immune cells within the uterus. The purpose of these cells is to detect and destroy foreign cells in the uterus, like infections or cancer cells. Women with a higher level of these natural killer cells are more prone to miscarriages and failed IVF procedures due to the natural killer cells destroying the natural or implanted egg.
For decades women have experienced failed implant procedures with no known reason or cause of the failure. Everything seemed perfect and looked like success was imminent but then she would have a miscarriage. A miscarriage is more than “just a failed pregnancy”, especially to the couple who so terribly wish to have a child of their own. A miscarriage is a devastating blow to the potential parents to be.
Not your fault
You must keep in mind however that just because the procedure was not a success, you are not at fault. It happens, a lot. The greatest success rate for any demographic of women undergoing IVF is only about 40%. The average success rate is only about 27%. So when you are going into this be sure to keep an open mind and be extremely patient for the results.
What happens in the cells
What happens in a failed IVF treatment is that when the fertilized egg is implanted into the uterine wall these natural killer cells treat that egg as an unwanted foreign body. Because of this the natural killer cells destroy the fertilized egg, which then, of course, results in a failed IV FR treatment, and no pregnancy.
A new procedure to suppress the natural killer cells looks promising. By taking steroids like orally two weeks prior to the IVF treatment the immune system should become suppressed enough to allow the egg to successfully become an embryo.