Intralipid therapy and adverse reproductive outcome: is there any evidence?

Controversy exists regarding the benefits of intravenous intralipid therapy in patients with a poor reproductive history. It is frequently reported that there is no evidence to support the effectiveness, utility or safety for this treatment. While individual studies may be perceived as weak, a systematic review and meta-analysis were performed to determine if there is any advantage to patients. PubMed, Embase and Scopus searches were performed with the target populations being either recurrent pregnancy loss (RPL), or recurrent implantation failure (RIF) undergoing assisted reproductive technology (ART) and receiving intralipid infusions. These cohorts were compared with either placebo, no intervention or alternative treatments. The most relevant outcome measures were considered to be clinical pregnancy rate (CPR), live birth rate (LBR), implantation rate (IR) and miscarriage rate (MR). Twelve studies encompassing 2676 participants met the criteria for selection and were included and reviewed. Treatment of the target population with intralipid led to an improvement in IR (Odds Ratio (OR): 2.97, 2.05-4.29), pregnancy rate (OR: 1.64, 1.31-2.04), and LBR (OR: 2.36, 1.75-3.17), with a reduction in MR (OR: 0.2, 0.14-0.30). Although intravenous intralipid is not recommended as a routine treatment for recurrent miscarriage or implantation failure, there is enough data to suggest consideration in selected patients where routine testing is unremarkable, standard treatments have failed and immunological risk factors are present. The presence of abnormal uterine natural killer (uNK) cells needs more study as a target marker to determine those who could benefit. LAY SUMMARY: There is controversy regarding the benefits and efficacy of intravenous intralipid therapy in patients with a poor reproductive history. It is frequently reported that there is no credible evidence to support their use. A situation we frequently face as medical professionals is patients asking us to consider immune therapy (such as intralipid) for reproductive failure where good quality embryos have been used. Intralipid infusions have been reported to improve pregnancy rates with IVF, and reduce the miscarriage risk in selected patient groups, but study results are not universally accepted. We have performed a detailed review and analysis of the literature to determine if there is any benefit to this immune treatment in specific patient groups. Our paper identified and analyzed 12 studies, finding that treatment with intravenous intralipid leads to an improvement in implantation, pregnancy and live birth rates, with a decrease in miscarriage rate. This study shows that there is evidence to suggest consideration of intralipid in certain patients where standard treatments have failed.