What is the purpose of this study?

During pregnancy the foetus develops in the womb attached to the mother’s blood supply. This is a unique situation when a tissue, which is substantially different from that of the mother, survives for a long period without rejection. The mechanisms that allow this process to happen are far from understood.

Recently a specific type of cell in the human immune system, so called Natural Killer (NK) cell, have received attention both in the scientific community and in the media. Small studies claim that increased numbers or increased activity of NK cells in the mother’s blood may result in the failure of a fertilised egg being implanted in the lining of the uterus, potentially causing infertility or poor outcome in vitro fertilisation (IVF).

The potential role of paternal sperm derived white blood cells and soluble factors in activating non-pregnant endometrial NK cells

What is the purpose of this study?

The successful outcome of a pregnancy requires, amongst other things, that the placenta grows well so that it can supply the developing foetus. If placental growth is insufficient this can lead to a number of problems, for example babies that are small when born (intrauterine growth retardation) or high blood pressure and kidney problems in the mother (pre-eclampsia). The reason(s) why the placenta fails to develop in some pregnant women are poorly understood. However, recently it has been shown that certain cells in the pregnant womb, so called uterine NK cells, produce chemicals that help the development of blood vessels in the placenta. These uterine NK cells are present in very large numbers in the womb during a healthy pregnancy. However, we don’t know where these cells come from.