Reproductive Immunology

Reproductive Immunology

Intralipid therapy at Sims IVF



In some cases, pregnancy may be hampered by the inability of the embryo to become implanted in the womb and this problem can be recurrent.  Very often implantation failure is missed or misunderstood by fertility clinics.  At Sims IVF, we have developed considerable expertise in the area of recurrent implantation failure.

We investigate a number of elements that could have a negative impact on implantation including blood clotting, endometrial receptivity and, in particular, the immune system.  All three of these elements, individually or collectively, could result in failure of the embryo to implant even if the embryo is viable.

There has been increased focus in recent years on the immune system and there are now a number of ways to manage it, in order to facilitate successful implantation.  There is evidence to suggest that these strategies are showing positive results.

Sims IVF carries out a number of tests to identify immune system problems.  One to test whether you have antibodies in your system that might hamper the conception and pregnancy process.  The second test checks for Natural Killer (NK) cells, NK T-cells and general maternal cytokine profiles which are mediated by CD4 positive T-cells - all of which might have been overstimulated at some point.

In vitro investigations employed at Sims IVF over the past 8 years reveal that intralipids have the ability to suppress NK cytotoxicity above and beyond that of IVIG, the previous agent employed. How this actually happens, is still unclear.

Published evidence from both animal and human studies, as well as our own investigations, suggest that intralipid administered intravenously may enhance implantation and help maintain a healthy pregnancy when the patient has an abnormal NK cell level or function.  We therefore recommend Intralipid Therapy for patients that have high NK cytotoxicity.



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Roussev RG, Ng SC, Coulam CB. Natural killer cell functional activity suppression by intravenous immunoglobulin, intralipid and soluble human leukocyte antigen-G. Am J Reprod Immunol. 2007 Apr;57(4):262-9.

Kurzer M, Tice D, Meguid MM, Reinitz ER. Natural killer cell activity in rats infused with Intralipid. J Clin Lab Immunol. 1989 May;29(1):33-5.