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Reproductive immunology tests and treatment

Treatment add-on

Reproductive immunology tests and treatment is rated red

Reproductive immunology tests and treatment is rated red


What does this traffic light rating mean?

The traffic light rating system consists of three colours that indicate whether the evidence, in the form of high-quality randomised control trials (RCTs), shows that a treatment add-on can safely improve the live birth rate for someone undergoing fertility treatment.

We give a red symbol for an add-on where there is no evidence to show that it can improve live birth rates. We also give a red symbol for an add-on where there is evidence to show that the add-on is unsafe.

The January 2019 consensus statement between the HFEA and 10 other professional and patient bodies agreed that treatments that have no robust evidence of their safety and/or effectiveness should only be offered in a research setting. Patients should not be charged extra to take part in research, including clinical trials, and should not be charged to use red-rated treatment add-ons if the reason for its use is to improve live birth rates.

For specific patient groups there may be reasons for the use of a treatment add-on other than to increase live birth rate, for example to reduce your chances of having a miscarriage. In these situations it may be appropriate for you to be offered a treatment add-on as part of your treatment and not in a research setting.

What is reproductive immunology tests and treatment?

Reproductive immunology is a field of study that looks at how a patient’s immune system reacts when they become pregnant.

Usually, your immune system works by fighting off any invading cells that it doesn't recognise because they don't share your genetic code. In the case of an embryo, the immune system learns to tolerate it even though it has a different genetic code from the mother.

Some scientists believe that in some cases of miscarriage or infertility, the mother’s immune system may fail to accept the embryo due to differences in their genetic codes.

Are there any risks?

There are various treatments associated with reproductive immunology which are used to suppress the body’s natural immunity, and all of which have risks:

  • Steroids (e.g. prednisolone): Risks include high blood pressure, diabetes and premature birth.
  • Intravenous immunoglobulin (IVIg): Side effects can include headache, muscle pain, fever, chills, low back pain, and rarely thrombosis (blood clots), kidney failure and anaphylaxis (a bad allergic reaction to the drug).
  • TNF-a blocking agents (eg adalimumab, infliximab): Remicade is not recommended for use during pregnancy. Side effects can include infections including septicaemia, chronic infections such as tuberculosis, and severe allergic reactions to the drug.
  • Intralipid infusions: Side effects include headache, dizziness, flushing, nausea and the possibility of clotting or infection.

What’s the evidence for reproductive immunology tests and treatment?

At the June 2018 Scientific and Clinical Advances Advisory Committee (SCAAC) meeting the Committee evaluated the evidence base for reproductive immunology.  Minutes of the June 2018 discussion and the evidence used to inform this discussion are available here.

There is no convincing evidence that a woman’s immune system will fail to accept an embryo due to differences in their genetic codes. In fact, scientists now know that during pregnancy the mother’s immune system works with the embryo to support its development.

Not only will reproductive immunology treatments not improve your chances of getting pregnant, there are risks attached to these treatments, some of which are very serious.

What are treatment add-ons?

Treatment add-ons are optional additional treatments that you may be offered on top of your routine fertility treatment, often at an additional cost. Some clinics may refer to treatments add-ons as ‘supplementary’ or ‘embryology treatments’. There are a wide range of treatment add-ons on offer including tests, drugs, equipment, holistic or alternative therapies, and surgical interventions.

However, all treatment add-ons share one common characteristic: they claim to improve the chances of having a baby (live birth rate). Evidence on whether some treatment add-ons are safe or effective is often missing or absent. These claims can attract a lot of attention with many patients opting for a treatment add-on thinking that it may be the best option for them despite there being little or no evidence to prove it is.

Treatment add-ons have varying levels of scientific evidence to support their effectiveness and safety and, at times, this evidence can be contradictory. It is important to keep in mind that for most patients, routine fertility treatment is an effective option on its own.

We aim to publish clear and reliable information about some of the treatment add-ons that lack sufficient evidence to show that they are effective and/or safe. This allows patients to make an informed decision about whether using a treatment add-on as part of their treatment is the best option for them.

To make it easier to understand the scientific evidence for each treatment add-on we have developed the HFEA’s traffic-light rated list of add-ons.


Review date: 25 August 2022

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