Sitting in the doctor’s office for the second time this year, you and your husband have been met with the devastating news that you have had another miscarriage. Although you’re finding it hard to take in any new information at this moment, you keep hearing the doctor referring to potential “immunological causes”.

Immunological causes? How could that be related to your miscarriage? You and your husband are young, fit, and healthy. You’ve both always taken the necessary steps to keep your immune systems functioning well.

How could this be?

If you have been informed that your recurrent miscarriages could be related to immunological causes, it’s understandable to feel confused and bewildered. However, the immune factors that can affect pregnancy are very complex, and there is still much medical research to be carried out to further our understanding of this topic.

So, if you’re feeling in the dark about the immunological causes that could have affected your pregnancies, we are here to help you feel better informed.

Here are some of the known immunological causes of recurrent miscarriage and the treatments used to counteract them.

Alloimmune miscarriage

‘Alloimmunity’ is the immune reaction that occurs between the tissues of different humans.

Some studies have suggested that abnormality in the immune relationship between the mother and the fetus is a cause of miscarriage. This means that if a mother shares too many genetic similarities with the father of her child, then miscarriage might occur as a result. This is because, in order for a mother’s body to form the appropriate protective response towards the baby, her immune system would need to recognise the ‘foreign’ nature of her baby. If the fetus was made up of genes that were too similar, this would theoretically not be able to happen.

Immune therapies for alloimmune miscarriage:

Although there is an apparent lack of data to support the hypothesis of alloimmune miscarriage, some couples are still advised to undergo forms of immune therapy to reduce their risk of further recurrent miscarriages. An example of this is white cell transfusion. It is important to mention that the results from immunotherapies have been varied, and some experts even say they are very much against them. Overall, while some trials say the treatments are beneficial, others say they have no benefit at all.

White cell transfusions

A white cell transfusion is an immune treatment that works by immunising or vaccinating the pregnant woman with the white blood cells taken from her partner. This is in turn supposed to prime her immune system to create a protective response for a pregnancy she will have in the future. When the woman becomes pregnant in the future, her body will then recognise the same foreign genetic material from the father of her baby, the correct immune response will be therefore recognised, and the baby won’t be rejected via miscarriage. However, bear in mind that there have been reports of various issues with this type of therapy.

Measuring peripheral blood natural killer cells

When a woman experiences recurrent miscarriage, the natural killer cells or NK cells in her blood are often measured to understand whether she would benefit from immune therapies that would help protect their next pregnancy from attack. This is because NK cells play a huge role in the innate immune response. They recognise any foreign material (antigens) that could be harmful, which means that they could have an adverse effect on a developing baby.

Intravenous immunoglobulin (IVIG)

Intravenous immunoglobulin (IVIG) is made out of antibodies extracted from the plasma component of blood for various donors. Typically, it is used as a treatment for a variety of auto-immune diseases and immune deficiencies. The way that it works is that immunoglobulin infusions can help a mother’s immune system to clear up any foreign antigen material in her body that has been produced as a reaction to her baby which is still developing. Because of this, an immune rejection of her baby due to genetic differences would be prevented, and women with a history of unexplained recurrent miscarriages could benefit. However, IVIG treatment has been linked to certain side effects and unpredictable risks, such as muscle pains, fevers, chills, low back pain, headaches, blood clots, kidney failure, anaphylaxis, and HIV and Hepatitis transmission.

In part two of this article, we will be exploring other immunological causes of recurrent miscarriage and other various treatments, such as autoimmune miscarriage, blood group incompatibilities, and inherited immune deficiencies.

What are the immunological causes behind recurrent miscarriage? (Part 1)

Unii looks at a heartbreaking question for any parent.