Intralipid infusion for IVF

What is an intralipid infusion?

• Intralipid infusion involves having a liquid containing lipids (fats) given through an intravenous (IV) line (into a vein in the arm).
• Intralipid is a liquid containing lipids (fats). It is mostly made up of soybean oil, egg yolk and glycerine.
• Intralipid infusion is commonly used as food or nutrition for people who can’t eat normally, such as after surgery.
• It has also been suggested that intralipid infusion may also play a role in suppressing the immune system.

Why might intralipid infusion improve IVF outcomes?

• The immune system plays an important role in embryo implantation and pregnancy.
• There are many different immune cells in the endometrium (lining of the uterus), including natural killer cells.
• It has been suggested that IVF patients who experience repeated implantation failure or repeated miscarriage have higher levels of immune cells, such as natural killer cells, than average. However, this has not been proven as the results of scientific studies have been mixed.
• Intralipid infusion is suggested to reduce the activity of the natural killer cells and other immune cells in the endometrium. In people with high levels of natural killer cells, it may help bring them back to a normal range.

Why might intralipid infusion not improve IVF outcomes?

• Most patients probably have a normal level of immune cells or immune activity in their endometrium.
• Natural killer cells and other immune cells help with embryo implantation, so having enough of them is important. If levels are normal or low, using intralipid could actually make things worse. While some patients might benefit from intralipid infusion, others might have a lower chance of getting pregnant after using it (i.e. intralipid infusion might reduce their IVF success rate).
• It’s unclear whether higher or lower levels of immune cells actually impact pregnancy success. Some research suggests that people with an "overactive" or "underactive" immune system in the uterus have the same chance of getting pregnant as those with normal immune activity.
• Immune tests, like those measuring natural killer cells, have not been proven to reliably detect an overactive or underactive immune response. These tests haven’t been validated, and there is no definition for what is considered a “normal,” “high,” or “low” natural killer cell level.
• It is important to remember that implantation failure and miscarriage are common. Most of the time when embryos fail to implant or are miscarried it is due to genetic or chromosomal problems in the embryo itself, rather than issues with the endometrial lining. Therefore, intralipid infusion may not be expected to make much difference to the chance of IVF success.

Who might consider intralipid infusion for IVF?

People who have experienced:

• Recurrent implantation failure
• Recurrent pregnancy loss (recurrent miscarriage)
• High levels of Natural Killer Cells

Does intralipid infusion in IVF work? What the evidence says

It is unclear whether intralipid infusion has any effect on the chance of pregnancy, miscarriage, or live birth from IVF. Many of the trials identified had to be excluded for trustworthiness concerns (see excluded studies below). Therefore, only one small trial was included which has serious flaws, so the results are not reliable or trustworthy.

Side effects of intralipid infusion

Side effects that may be expected after an intralipid infusion include:

• Hypersensitivity reaction – signs of allergy such as rash, itching, hives, swelling (a serious side effect that needs urgent medical attention)
• Headache
• Rise in body temperature
• Nausea and vomiting
• Shivering and chills
• Flushing (sensation of warmth and redness of the skin)
• Skin rash and hives
• Rapid breathing and shortness of breath
• Effects on blood pressure
• Slight pressure over the eyes
• Abdominal pain
• Dizziness.

All medicines can have side effects.

For more information:

• Patient information leaflet for intralipid
• For information about safety of medicines in pregnancy, search for the name of any medicine on the ‘Best use of medicines in pregnancy (Bumps)' website

Risks of intralipid infusion and long-term outcomes

It is unknown whether there are any risks or long-term harms from intralipid infusion during IVF.

• This is based on data from randomised controlled trials and input from IVF specialists. Possible risks of harm and long-term outcomes are often not reported in randomised trials and therefore it is unknown whether intralipid poses any risk of harm to the IVF patient or the embryo/baby.

Intralipid has been used in Australia since 2015, and approximately 5,000 IVF cycles have used intralipid infusion.

Cost of intralipid infusions for IVF

Intralipid infusions for IVF usually costs between $300-500 AUD per infusion. Multiple infusions may be recommended.

Cost information is indicative only, costs can vary from clinic to clinic and depending on different circumstances.

Practical considerations about intralipid infusions for IVF

Intralipid infusion should not be given to someone with an allergy to soy, eggs, peanuts or any of the ingredients in intralipid.

Intralipid infusions must be administered by a healthcare professional. First, a needle is inserted into a vein in the arm. Then the intralipid is administered slowly over a period of approximately two hours. Often, more than one infusion may be recommended. It is usually undertaken within a few days before a planned embryo transfer, and in the days or weeks following an embryo transfer.

Unsure about some of the terms we have used? Use our glossary to understand scientific or unfamiliar terms.