Intralipid is a fat emulsion that was developed for use as a caloric source for patients who were unable to achieve adequate nourishment through an oral diet. Intralipid is also used as a solution to deliver drugs that are poorly soluble in water such as the commonly used anesthetic drug propofol. Whereas side effects are uncommon, they include high triglyceride levels, acute pancreatitis, cholestasis and increased risk of infection. Intralipid is made of purified soybean oil, egg phospholipids, glycerol and water. It provides essential fatty acids, linoleic acid, omega- 3 and 6 fatty acids and alpha-linolenic acid.
The effects of Intralipid in suppressing natural killer cell activity (NKa) were found to be comparable to intravenous immunoglobulin (IVIG) by laboratory experiments. Additionally, it’s been shown that Intralipid suppresses NKa similar to IVIG in women with immune and reproductive problems. Some of these issues may be related to immune implantation problems or genetic mismatch situations and in others due to recurrent miscarriages or repeated in vitro fertilization (IVF) failures.
Typically, Intralipid and IVIG treatment is administered at least one week prior to the expected date of embryo transfer, repeated post-transfer and continued throughout the first trimester based on the degree of NKa suppression. Treatment can be continued during the second trimester depending on elevated NKa and the severity of the immunological problem. Large scale studies are still needed to document the clinical benefits of Intralipid and IVIG treatments in patients with infertility and recurrent pregnancy loss.