Association of Intralipid Infusions With Birth Outcomes and First-Trimester Placental Biomarkers in Frozen Embryo Transfer Cycles: A Retrospective Cohort Study.

BACKGROUND

Intralipid is used as an adjunctive therapy in assisted reproductive technology (ART), but data regarding pregnancy outcomes and early placental biomarkers are limited.

AIMS: To evaluate the association between Intralipid exposure during frozen embryo transfer (FET) cycles and pregnancy outcomes, birthweight and first-trimester placental biomarkers.

MATERIALS AND

METHODS

This retrospective cohort study included 729 women undergoing FET cycles resulting in delivery beyond 20 weeks at a private assisted reproduction clinic between 2017 and 2023. Outcomes were compared between women receiving intravenous Intralipid (n = 136) and those not receiving Intralipid (n = 593). Multivariable analyses adjusted for maternal age, body mass index, parity, plurality, foetal sex, cycle type, intracytoplasmic sperm injection (ICSI) use and preimplantation genetic testing for aneuploidy (PGT-A) status.

RESULTS

Individual pregnancy outcomes, including preterm birth, hypertensive disorders of pregnancy, gestational diabetes, foetal growth restriction, congenital anomalies and stillbirth, did not differ significantly between groups. Intralipid exposure was not independently associated with the composite adverse pregnancy outcome after adjustment (adjusted OR 2.08, 95% CI 0.73-5.96; p = 0.171). Intralipid-exposed pregnancies had lower first-trimester PAPP-A MoM values after adjustment (adjusted geometric mean ratio 0.86, 95% CI 0.76-0.98; p = 0.021), whereas PlGF and free β-hCG concentrations did not differ significantly. Lower PAPP-A concentrations were not associated with birthweight z-scores.

CONCLUSIONS

Intralipid exposure was not independently associated with adverse pregnancy outcomes after adjustment. Pregnancies exposed to Intralipid had lower first-trimester PAPP-A measures without corresponding differences in other placental biomarkers or birthweight z-scores. Linkage of the Australia and New Zealand Assisted Reproduction Database with perinatal outcome registries, with routine capture of adjunctive ART therapies, would support more comprehensive maternal and neonatal safety evaluation.