Outcomes Among Women Using Low-dose Aspirin and Undergoing Euploid, Autologous, Programmed Frozen Embryo Transfer Cycles: A Retrospective Cohort Study

Background: Low-dose aspirin (LDA) has been used during assisted reproduction; however, the evidence supporting its use remains conflicting. Aim: To assess whether LDA improves the clinical pregnancy rate (CPR) in a patient’s first autologous, programmed, single frozen embryo transfer (FET) cycle with an euploid embryo. Settings and Design: Retrospective cohort study at an academic center. Materials and Methods: A retrospective cohort study of all first autologous, programmed, single FETs of a single euploid embryo performed at our academic center between 2020 and 2022 assessed the association between LDA and CPR and live birth rate (LBR). A subgroup analysis assessed the prevalence of hypertensive disorders of pregnancy (HDP). Statistical Analysis Used: Chi-square tests of association and fixed-effects multivariable logistic regression were performed. Among patients with a live birth, Chi-square tests of association were utilised. Binary logistic regression was performed, adjusting for age and body mass index. Data were analysed using SAS software, version 3.8, Enterprise Edition (SAS Institute Inc., Cary, NC, USA). Statistical significance was set at P < 0.05. Results: Two hundred seventy FETs resulted in 189 clinical pregnancies, and 153 live births. LDA was not associated with CPR or LBR. LDA was also not associated with HDP, although this outcome was only able to be assessed among one hundred twenty patients (78% of all live births). Conclusion: LDA use was associated with neither clinical pregnancy nor live birth among autologous, euploid, programmed, single FET cycles.