Abstract Study question Which factors effect the likelihood of live birth after euploid frozen embryo transfer (FET) in recurrent pregnancy loss (RPL)? Summary answer Female age and number of previous pregnancy loss do not effect the live birth rates after euploid blastocyst FET. What is known already PGT-A is helpful to discard the aneuploid embryos and has been proven to improve pregnancy outcomes and reduce miscarriage rate per embryo transfer. As approximately 50% of clinical miscarriages have chromosomal abnormalities, PGT-A has been suggested as a treatment option for RPL. However it is questionable on the cost effectiveness, effect on prognosis and labor-intensive. In addition, currently PGT-A use is not recommended by any society guidelines in RPL patients. ESHRE guideline on RPL stated ‘All couples with results of an abnormal fetal or parental karyotype may be informed about the possible treatment options available including their advantages and disadvantages.’ Study design, size, duration This retrospective cohort study from January 2018 to January 2023 was conducted at Bahçeci Health Group included patients underwent PGT-A/ICSI cycles. Patients with RPL (2 or more clinical pregnancy loss) had a complete RPL workup recommended by ASRM and reported no etiology for RPL was included in the study. Patients with uterine synechia, hydrosalpinx, endocrinological disorders and thin endometrium (endometrial thickness <6mm) were excluded Participants/materials, setting, methods A total of 366 single euploid blastocyst FETs employing hormone replacement therapy for endometrial preparation were evaluated. Patients were categorized into 2 group regarding female age (female age< 35 years and female age≥35 years. Demographic, embryological and endocrinological parameters were analyzed. Live birth rate (LBR) was the primary outcome. Clinical pregnancy rate (CPR) and miscarriage rate (MR) were the secondary outcome. Main results and the role of chance The mean female age of the study population was 33.9±4.6 years, the number of previous pregnancy loss was 3.2±1.6 and BMI was 23.8 ±7.9 kg/m2. Overall CPR, MR and LBR were 61.7% (226/366), 24.8% (56/226) and 46.5% (170/366) respectively. Comparison of clinical characteristics of the 195 women <35 years and 171 women ≥35 years revealed no significant deference in BMI, number of previous live birth, and number of previous pregnancy loss. CPR, MR and LBR were similar among two groups [ 63.6% (124/195) vs 59.6% (102/171), p = 0.44; 27.4% (34/124) vs 21.6% (22/102), p = 0.31; 46.2% (90/195) vs 46.8% (80/171), p = 0.9; respectively]. Binary logistic regression evaluating the independent factors that effect live birth revealed that female age and number of previous pregnancy loss were not found to be statistically significant factors. The only independent factor for live birth was day of embryo biopsy, transferring the day 6 biopsied embriyo significantly decreased the live birth [p = 0.003, OR: 0.47, 95% CI (0.29-0.77)]. Limitations, reasons for caution The maim limitation of the study is its retrospective nature. Wider implications of the findings PGT-A has been suggested to be a treatment for RPL. However there is insufficient data to call PGT-A as an efficient treatment for RPL. Investigating the factors that effect live birth after PGT-A may be the first step for selecting the most favorable group Trial registration number Not applicable