Reproductive immunology looks at how the immune system reacts when a woman becomes pregnant. Your immune system keeps you healthy by identifying and fighting off any foreign cells it doesn't recognise because they don't share the same genetic code as the rest of the cells in the body. Although an embryo is genetically different to the mother, a unique immunological adaptation takes place to allow the embryo to implant and the immune system learns to tolerate it. If this adaptation is impaired, it may lead to difficulty conceiving or cause miscarriage.
When might we suggest reproductive immunology?
- If you have experienced recurrent miscarriage
- If you have had previous unsuccessful cycles of IVF
- If you have a history of immune disorders (e.g. rheumatoid arthritis, lupus, Crohn’s disease, or psoriasis)
- If you have had previous pregnancies with placenta related complications such as pre-eclampsia, premature delivery or fetal growth restriction
- Screening for auto-immune antibodies
- Natural Killer (NK) cell assay – NK cells are a type of white blood cell that protect us from bacteria and viruses and other invaders. Some research has suggested that raised NK levels in the blood and the endometrium may be associated with IVF failure and recurrent miscarriage
- TH1/TH2 intracellular cytokine ratios. Cytokines are chemical messengers produced by your immune cells. Cytokines produced by TH2 immune cells are thought to support pregnancy whereas the cytokines produced by TH1 immune cells may inhibit pregnancy. For successful pregnancy, TH2 cytokines should be dominant.
- treatment with heparin to moderate blood clotting and the immune response
- steroid treatment to dampen the inflammatory response.
- low dose aspirin
- intravenous intralipid infusion
The independent regulator of fertility treatment, the Human Fertilisation and Embryology Authority (HFEA), has developed a ‘red-amber-green’ rating system for treatments that are optional extras in fertility treatment. They consider that the only way to be confident that a treatment is effective enough to be used routinely is to carry out a randomised controlled trial (RCT). In an RCT, patients are assigned randomly to two groups: a treatment group, given the new treatment and a control group, given either a well-tried treatment or a placebo.
The HFEA has given reproductive immunology tests and treatments (the name given to treatment using intralipid and steroids) because it considers that there is no evidence these tests or treatment increase the overall chances of having a baby. We recommend that you read the information on the HFEA website before making a decision about having the tests and treatment outlined here.