Evaluation of intralipid effect on pregnancy outcomes in women with recurrent implantation failure: A retrospective cohort study.

BACKGROUND

Recurrent implantation failure remains a challenge in assisted reproduction. Intralipid has been proposed as an immunomodulatory intervention to improve outcomes, although evidence remains inconsistent.

OBJECTIVE

This study aimed to evaluate the effect of intralipid on pregnancy outcomes in women with a history of at least 2 failed embryo transfer cycles.

MATERIALS AND

METHODS

In this retrospective cohort study, data of 270 women with ≥ 2 failed embryo transfer cycles, who underwent a subsequent frozen embryo transfer (FET) at Avicenna Fertility Center, Tehran, Iran, from March 2021-2022 were extracted from medical records. Participants were allocated to the intralipid group (n = 132), receiving 100 mL intravenous intralipid 20% 1 wk before FET, if beta-human chorionic gonadotropin was positive, the same dose was given every 4 wk until the end of the first trimester, or to the control group (n = 138), undergoing routine FET treatments. Outcomes included biochemical, clinical, and ongoing pregnancy, abortion, and live birth.

RESULTS

Biochemical pregnancy rate was significantly higher in the intralipid group compared with controls (51.5% vs. 37.7%, p = 0.022). Clinical pregnancy (43.2% vs. 36.2%), ongoing pregnancy (28.8% vs. 18.8%), and live birth (25.8% vs. 17.4%) also favored the intralipid group, although these differences did not reach statistical significance (p > 0.05). Abortion rates were comparable between groups (25.8% vs. 21.0%, p = 0.357).

CONCLUSION

Intralipid may improve biochemical pregnancy rates and shows a non-significant positive trend in other pregnancy outcomes in recurrent implantation failure cases, warranting confirmation in larger randomized controlled trials.