Embryo Toxic Factor (ETF)
Some of the common causes of miscarriage are due to pregnancy complications such as blighted ovum, ectopic pregnancy or molar pregnancy. However, women who experience multiple miscarriages will likely require further assessment in order to determine whether or not an underlying condition may be affecting fertility. Among the various fertility testing procedures that may be performed is the embryo toxic factor (ETF) test.
What is Embryo Toxic Factor?
Embryo toxic factor is a cytokine that is secreted by the immune system’s white blood cells in response to pregnancy tissue. If excess amounts of ETF are produced by white blood cells during pregnancy, the immune system may recognize the embryo as a foreign substance and may attack the embryo in order to maintain the body’s health. This in turn will lead to a miscarriage.
Diagnosing Embryo Toxic Factor
Diagnosing embryo toxic factor requires a complicated procedure involving laboratory analysis. For this reason, unless a woman suffers from recurrent miscarriages and requires testing for infertility, this type of diagnostic procedure will not be performed. In fact ETF testing is not a routine procedure, and is considered an experimental testing method.
ETF testing involves two stages to determine whether or not the body is producing an immune system response to pregnancy. The test aims to assess whether or not the body’s lymphocytes (white blood cells) are producing any type of substance that would be harmful to a developing embryo.
A blood sample will first be taken in order to isolate certain lymphocytes. These lymphocytes will be treated with a solution and left to culture for several days. These lymphocytes will then be combined with cultured mouse embryos and allowed to sit for several days. A fertility specialist will then assess the embryo development as it is affected by these lymphocytes. If the embryos have stopped developing or have died, the presence of ETF will be determined. If the embryos are developing normally, no ETF is secreted.
ETF Treatment and Miscarriage Prevention
In order to prevent the recurrence of miscarriage, certain treatment options are available for women with embryo toxic factor. Treatment of ETF to avoid further pregnancy complications typically involves immune system suppression in order to allow embryo development and implantation to occur. Treatment may involve the following:
- progesterone in vaginal suppositories or gel caps taken until the sixteenth week of pregnancy
- IVIg infusions from donor blood
- progesterone oil injections in cases when the women is undergoing IVF treatment
Progesterone is commonly used to increase hormone levels and strengthen the uterus, and in higher doses works to suppress the immune system. Dosage is typically 200mg to 400mg, and is taken twice daily. Speak to your health care provider for more information regarding your particular health concerns.