Embryo implantation
The embryo generated from the egg and sperm during IVF needs to embed (implant) into the lining of a woman’s womb for pregnancy to take place. The chance of an embryo successfully implanting is only approximately 30%, meaning the chance of an embryo failing to implant is approximately 70%. The chance of pregnancy increases slightly with increasing numbers of transferred embryos such that the chance of two embryos failing to implant is 49%.

Definition of recurrent implantation failure
From the foregoing, we have calculated that in the absence of underlying problems, most women would have successfully achieved a pregnancy by their third cycle of IVF. Should this not be the case, the question arises if there is an underlying problem causing the lack of pregnancy. Recurrent implantation failure (RIF) is therefore generally defined as the absence of pregnancy (implantation) following 3 transfers of good quality embryos in IVF cycles.

Factors contributing to RIF
Many factors determine whether pregnancy occurs in an IVF cycle including:

Embryo factors:
Quality of the embryo: one important variable is clearly the quality of the embryo as a poor quality embryo is less likely to implant and lead to pregnancy. A good-quality embryo is one that has the correct number of normal cells corresponding to the day of its development.
Number of embryos transferred: there is no widespread agreement on the number of embryos transferred that qualify for the definition of RIF but most Specialists would agree to apply the definition after 3 unsuccessful embryo transfer procedures.
Stage of embryo development: blastocyst embryos are more likely to implant and lead to pregnancy than Day 2/3 embryos.

Maternal age:
The age of the woman is probably the most important determinant of the chance of pregnancy following an IVF cycle. Embryo quality is closely related to maternal age.

Uterine factors:
Inherited or acquired abnormalities of the womb can contribute to RIF including:


Endometrial factors:


Investigation Options available include:

Treatment Options available include:


Information on  Aspirin & Steroids

What is Aspirin?  Aspirin is commonly known as a pain killer when taken in its standard dose (300-600mg) but not widely known for its anti-blood clotting functions. Aspirin prevents excessive blood clotting when taken in small doses (75mg) and so is useful in this dose in situations where we wish to prevent excessive blood clotting and/or encourage adequate blood flow through small blood vessels. We recommend that Aspirin is taken as a daily tablet on a full stomach.
What is Prednisolone?  Prednisolone is a steroid; this is a substance found widely in many hormones and immune mediators in the body. Steroids are therefore a class of drugs that mediate many body reactions and generally boost the functioning of body systems. They are commonly used to mediate immune functions to prevent excessive body reactions to immune stimulus and so reduce inflammation, pain and disease. We recommend that Prednisolone is taken as a daily tablet on a full stomach.
Why do we sometimes recommend Aspirin and/or Prednisolone for women undergoing IVF? 

We may recommend the use of Aspirin and/or Prednisolone to improve the chances of pregnancy and live birth during IVF treatment in women with the following conditions: 

How do we administer Aspirin?  We normally provide Aspirin as 75mg tablets as part of your IVF drug package whenever we prescribe it. We recommend you take one (1) tablet daily starting on the day you commence ovarian stimulation with Menopur, Gonal-F or both. Please take your Aspirin on a full stomach and continue taking one tablet daily until advised to stop by a member of the CFC team. If you become pregnant, we generally recommend continuing with Aspirin until 36 weeks of pregnancy unless advised otherwise by your Obstetrician. If you do not become pregnant, please stop taking Aspirin when you stop your other IVF medication (Cyclogest).
How do we administer Prednisolone?  We normally provide Prednisolone as 5mg tablets as part of your IVF drug package whenever we prescribe it. We prescribe Prednisolone either in 10mg or 20mg doses and so recommend that you take two (2) tablets together if on 10mg or four (4) tablets together if on 20mg doses. Start taking Prednisolone from the morning following your egg collection or as otherwise advised by the CFC team. Please take Prednisolone on a full stomach preferably in the morning and continue the medication until advised to stop by a member of the CFC team. We normally continue with Prednisolone whilst you remain on Cyclogest (Progesterone) and wean you off Prednisolone when we stop the Cyclogest.
Are Aspirin and Prednisolone safe to use in pregnancy?  Aspirin and Prednisolone are relatively safe drugs to use in pregnancy and there is robust data on their use in this situation. As always, we would prefer you do not take any medication that is not necessary in a pregnancy situation and so would only prescribe these drugs if we believe their benefits in your situation outweigh the risks of their use.
What side effects could you experience with Aspirin and Prednisolone?  Aspirin is a very well-tolerated drug with few side effects but has been known to cause gastric disturbance (especially if taken on an empty stomach), nausea and vomiting. It’s rare for Aspirin in the low doses (75mg) we use for IVF to cause bleeding problems but we recommend you advise your healthcare providers that you’re taking Aspirin if you develop any bleeding whilst using it. Prednisolone is a well-tolerated drug with few side effects but has been known to cause nervousness, mood changes, irritability, headaches, bowel dysfunction and insomnia. More severe side effects of Prednisolone are unusual but always discuss with a member of the CFC team if you have any concerns.
Any further questions? We hope you have found this information helpful but please speak to your CFC Fertility Nurse on 01625 264 110 if you have any further questions.


Information on Intralipids

What is intralipid therapy? Intralipid infusion therapy is a sterile fat emulsion containing soy oil, chicken egg yolk, glycerine and water.  The infusion is in liquid form and administered intravenously.  It is a non- invasive procedure carried out in clinic as part of a treatment cycle.

Why is it used? Research has found that raised natural killer cell activity (toxic white blood cells) can act against an embryo and prevent its implantation into the endometrium.  This is known as implantation failure.

In addition, some auto immune disorders can also have a detrimental impact upon the healthy implantation and early progress of an embryo which can also cause implantation failure and early miscarriage. Intralipid therapy is designed to combat these factors.

Who may benefit from intralipid therapy? Intralipid infusions can help women who have had implantation failure or early miscarriage/s.  Treatment is available for women as part of a treatment cycle at Cheshire Fertility or women having treatment elsewhere in the UK or overseas.

When is the best time to have the infusions? A patient will have up to two or three intralipid infusions before a pregnancy test is due and up to three after a positive pregnancy test.  The infusions are given as prescribed by your specialist.

How are the infusions carried out?  As the intralipid is in liquid form it is administered by inserting a cannula (a fine plastic tube) into a vein in the arm or hand.  Each infusion takes around an hour during which the patient will be seated comfortably and in private.  The patient may eat and drink normally whilst the infusion is taking place and a clinical team member will monitor the patient throughout the appointment.

Are there any noticeable effects of the infusion?  There are no serious adverse effects with the infusion although some patients may experience a headache, nausea or flu-like symptoms.  The infusion is not given to anyone with a known allergy to soy oil, eggs, peanut, peanut based products or any active ingredients in the infusion.  After treatment the patient can resume normal activities such as driving.