Objective To investigate the effect of surgical intervention on IVF/ICSI assisted conception outcomes in patients with ovarian endometriosis(OEM).Methods OEM patients who underwent IVF/ICSI treat-ment at the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University between January 1,2019 and February 1,2024 were selected,including 228 cases in the non-operated group before assisted conception(Group A)and 426 cases in the operated group before assisted conception(Group B),and the assisted concep-tion outcomes of the two groups were analysed.Results There were no statistically significant differences in female age,BMI,infertility years,infertility type,and basal FSH level between the two groups(P＞0.05).AMH level and basal AFC were higher in group A than in group B(P=0.003).There was no statistical difference in the application of ovulation induction programme,total number of Gn days and total amount of Gn between the two groups(P＞0.05),but the amount of Gn initiation in Group A was lower than that in Group B(P=0.011).Applying multiple linear regression to adjust for confounding factors,there was a statistical difference in the 2PN fertilization rate between Groups A and B(P=0.007),whereas there was no statistical difference in the number of eggs obtained,the rate of available embryos,the rate of high-quality embryos and the rate of blastocyst formation between the two groups(P＞0.05).After applying binary logistic regression to adjust for the influencing factors related to clinical pregnancy rate and live birth rate,the clinical pregnancy rate(aOR=-0.896,95％CI:0.540～1.488),live birth rate in the two groups(aOR=0.976,95％CI:0.589～1.620)remained statistically indistin-guishable.Conclusions Surgical intervention may further impair ovarian reserve function in patients with OEM,but does not appear to affect embryo quality or pregnancy outcome.Surgical treatment prior to assisted conception may improve fertilization rates in patients with OEM.

Objective To exploring the effect of inflammatory indicators on the outcome of assisted conception of in vitro fertilization/intracytoplasmic sperm injection(IVF/ICSI)in patients with ovarian endometriosis(OEM).Methods The study subjects were selected as the patients with OEM who received IVF/ICSI treatment at the Third Affiliated Hospital of Zhengzhou University from January 2019 to February 2024.Based on whether previous surgery for uterine endometriosis cyst removal had been performed,they were divided into non-surgery group(n=73)and surgery group(n=112).To explore the differences in inflammatory markers between two groups and to determine whether they have an impact on the outcome of assisted reproduction.Results The lymphocytes(L)and blastocyst formation rates of patients in surgery group were significantly higher than those in non-surgery group,platelet to lymphocyte ratio(PLR)and carbohydrate antigen 125(CA125)were significantly lower than those in non-surgery group(P＜0.05).There were no statistically significant differences in the clinical pregnancy rate and live birth rate between two groups of patients(P＞0.05).After adjusting for confounding factors,the results of multivariate Logistic regression analysis showed that L,PLR,and CA125 had no statistically significant impact on the clinical pregnancy rate and live birth rate(P＞0.05).Both maternal age and the number of embryos transferred exerted a certain influence on clinical pregnancy rates and live birth rates(P＜0.05),furthermore,the type of embryo transferred had a significant effect on clinical pregnancy rates(P＜0.05).Conclusion Compared with non-surgery group,surgery group had higher L level and lower PRL and CA125 levels,but these changes did not significantly affect clinical pregnancy or live birth outcomes in OEM patients undergoing IVF/ICSI assisted reproduction.

OBJECTIVE: To explore clinical effective and safety of subarachnoid block (SA), adductor canal block (ACB), and femoral nerve block (FNB) for early analgesia in anterior cruciate ligament (ACL) reconstruction. METHODS: From September 2022 to October 2023, 90 patients with ACL rupture who received unilateral knee arthroscopic ACL reconstruction were selected and divided into ACB group, FNB group and SA group according to different anesthesia methods, with 30 patients in each group. There were 12 males and 18 females in ACB group, aged from 18 to 60 years old with an average of (33.3±13.8) years old;14 patients with gradeⅠand 16 patients with gradeⅡaccording to American Society of Aneshesiologists (ASA);13 patients on the left side and 17 patients on the right side. There were 15 males and 15 females in FNB group, aged from 18 to 60 years old with an average of (33.5±12.9) years old;15 patients with gradeⅠand 15 patients with gradeⅡ;16 patients on the left side and 14 patients on the right side. There were 16 males and 14 females in SA group, aged from 18 to 60 years old with an average of (31.0±12.6) years old;18 patients with grade I and 12 patients with gradeⅡ;17 patients on the left side and 13 patients on the right side. In ACB and FNB groups, the nerve block of ACB and FNB were performed under ultrasound guidance before SA anesthesia with 15 ml of 0.3% ropivacaine. Visual analogue scale (VAS) and quadriceps muscle strength at rest and passive movement were recorded and compared among 3 groups at 4, 8, 12, 16, 24 and 48 h after operation, as well as the dosage of tramadol injection analgesics, incidence of nausea and vomiting, nerve block time and other complications within 48 h after operation were compared. RESULTS: All patients were followed up for 11 to 20 (15.8±2.4) months. VAS at 4, 8, 12, 16, 24 and 48 h after operation of SA group was significantly higher than that of ACB and FNB groups, with statistical significance (P<0.05). There were no significant difference in VAS of rest and passive movement at 4, 8, 12, 16, 24 and 48 h after operation between ACB group and FNB group(P>0.05). At 4, 8, 12 and 16 h after operation, the quadriceps muscle strength in SA and ACB groups was higher than that in FNB group, with statistical significance (P<0.05);but there was no statistical significance in quadriceps muscle strength among three groups at 24 and 48 h after operation(P>0.05). One patient occurred nausea and vomiting in ACB group, 2 patients in FNB group and 5 patients in SA group, and no significant difference among three groups (χ²=0.352, P=0.171). The dosage of tramadol in SA group was (300.00±136.50) mg, which was higher than that in FNB group (168.33±73.70) mg and ACB(163.33±70.70) mg, and the difference was statistically significant (P<0.05). There was no significant difference in nerve block time between ACB group and FNB group (t=1.964, P=0.054). There was no puncture site bleeding, local anesthesia drug poisoning and hematoma formation among three groups. CONCLUSION Both FNB and ACB could provide good early analgesia after ACL reconstruction, but ACB group has little effect on quadriceps muscle strength. Patients could have early postoperative functional training without pain, which is more beneficial to the recovery of knee joint function, and could reduce the use of analgesic drugs, without serious complications, which is safe and reliable method.
Humans ; Male ; Female ; Nerve Block/methods* ; Adult ; Anterior Cruciate Ligament Reconstruction ; Adolescent ; Middle Aged ; Young Adult ; Analgesia/methods* ; Pain, Postoperative/drug therapy* ; Femoral Nerve

OBJECTIVES: Transcervical resection of adhesions (TCRA) under hysteroscopy is the mainstay treatment for intrauterine adhesions (IUA), but its effectiveness varies depending on the surgical approach. This study aims to investigate the impact of different surgical techniques on endometrial repair and pregnancy outcomes in patients with secondary infertility and moderate-to-severe IUA. METHODS: A retrospective analysis was conducted on 225 patients who underwent TCRA followed by in vitro fertilization and embryo transfer between January 2021 and December 2022. Patients were grouped based on the surgical method: A cold knife group (n=127) and an electrosurgical group (n=98). Adhesions were separated using either cold knife or electrosurgical instruments. Postoperative visualization of uterine angle and tubal ostia, endometrial restoration, vascular endothelial growth factor (VEGF) expression in adhesion tissues, and clinical pregnancy outcomes were compared. Univariate and multivariate Logistic regression analyses were performed to identify factors influencing pregnancy outcomes. A LightGBM model was constructed to predict pregnancy outcomes. RESULTS: Compared with the electrosurgical group, patients in the cold knife group had significantly greater postoperative endometrial thickness [(8.86±0.53) mm vs (8.10±0.87) mm, P<0.05], higher live birth rates (64.57% vs 30.61%, P<0.05), and lower VEGF expression (1.31±0.09 vs 1.53±0.16, P<0.05). Logistic regression analyses identified age, number of visible tubal ostia postoperatively, and surgical method as significant factors affecting pregnancy outcomes (P<0.05). The LightGBM model based on surgical method had an area under the curve (AUC) of 0.882 (0.838-0.926), with internal validation AUC of 0.817 (0.790-0.840). CONCLUSIONS Cold knife surgery promotes faster recovery of the endometrial microenvironment and earlier improvement of fertility in patients with secondary infertility and IUA Surgical method is a key factor influencing pregnancy outcomes, and the LightGBM model based on surgical approach shows good predictive performance for pregnancy outcomes in patients with moderate-to-severe IUA.
Humans ; Female ; Pregnancy ; Tissue Adhesions/surgery* ; Retrospective Studies ; Adult ; Pregnancy Outcome ; Uterine Diseases/surgery* ; Hysteroscopy/methods* ; Infertility, Female/etiology* ; Electrosurgery/methods* ; Fertilization in Vitro ; Endometrium/surgery* ; Embryo Transfer ; Vascular Endothelial Growth Factor A/metabolism*

Objective:To explore the clinical efficacy of super-selective ophthalmic artery thrombolysis in the treatment of central retinal artery occlusion (CRAO).Methods:This is a retrospective case series study,based on the analysis of clinical data of 50 non-arteritic CRAO patients. The patients were advised to be treated with super-selective intra-ocular arterial thrombolysis at the Neurosurgery Department, Shenyang No. 4 People′s Hospital from May to December 2024, and treated with intra-arterial thrombolysis and postoperative management guidance by the Department of Neurosurgery, General Hospital of the Northern Theater Command. There were 36 males and 14 females, aged (59.5±10.2)years (range: 41 to 75 years). There were 5 cases of complete obstruction of the central retinal artery and 45 cases of subtotal obstruction.Before the operation, all patients underwent optical coherence tomography angiography (OCTA)+ocular vascular ultrasonography, and their visual acuity was measured using a standard visual acuity logarithmic scale, visual field was measured using the contrast visual field examination method;One week after the operation, all patients were rechecked for OCTA, visual acuity and visual field. The patients′ preoperative and postoperative visual field recovery status were compared. Significant effect was defined as an improvement of more than 3 lines of visual acuity or a complete improvement of visual field defects after treatment compared with pretreatment visual acuity; effectiveness was defined as an improvement of 1 to 2 lines of visual acuity or an improvement of visual field defects after treatment compared with pretreatment visual acuity.Results:The overall effective rate of 50 patients with CRAO treated with super-selective ophthalmic artery urokinase thrombolysis was 94.0% (47/50), with 29 very effective, 18 effective and 3 ineffective. The time from onset to surgery was 0 to 6 hours in 5 patients, with an effective rate of 5/5; >6 to 24 hours in 11 patients, with an effective rate of 10/11; >1 to 7 days in 21 patients, with an effective rate of 90.5%(19/21); >7 to 14 days in 9 patients, with an effective rate of 9/9; and >14 to 21 days in 4 patients, with an effective rate of 4/4, and the difference in effective rate between the different time windows of thrombolytic therapy was not statistically significant ( P=0.961). There were 3 cases of intraoperative and postoperative complications, including 1 case of ophthalmic artery entrapment, 1 case of femoral artery pseudoaneurysm and 1 case of fundus hemorrhage, but all of them were cured after symptomatic treatment. Conclusions:Intra-arterial thrombolysis for CRAO patients has a high effective rate and a low complication rate. The surgical time window can be extended to 21 days after the onset, which is of positive significance for the recovery and improvement of the patient′s final visual acuity.

Objective:To explore the effectiveness, safety, and cost among urinary follicle-stimulating hormone (u-FSH), recombinant FSH (r-FSH)α, and r-FSHβ in the early follicular phase prolonged protocol for patients under 35 years old with normal ovarian function.Methods:It was a retrospective cohort study. Patients under 35 years old with normal ovarian function who underwent early follicular phase prolonged protocol for ovulation stimulation and using in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) for fertilization in Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University from January 2018 to December 2023 were recruited, including the fresh and frozen-thawed embryo transfer (FET) cycles. Patients were divided into u-FSH group, r-FSHα group, and r-FSHβ group. A total of 1 048 ovarian stimulation cycles were included, with 150 cycles, 490 cycles and 408 cycles in the three groups respectively. A total of 710 FET cycles with fresh cycle cancellation were included, with 95 cycles, 320 cycles and 295 cycles in the three groups respectively. The baseline data, pregnancy outcomes, safety, and cost were compared among the three groups. The main observation indicators were cumulative pregnancy rate and cumulative live birth rate (CLBR). A binary logistic regression model was used to control confounding factors, and to analyze the relationship between three ovulation inducing medicine and CLBR. Results:The difference in the number of oocytes retrieved among the u-FSH group, r-FSHα group, and r-FSHβ group was statistically significant [13.0 (10.0, 16.0), 14.0 (11.0, 18.0), 15.0 (11.0, 19.0), respectively, P=0.012], and the difference in the number of 2PN embryos was statistically significant [9.0 (6.0, 12.0), 10.0 (7.0, 13.0), 10.0 (7.0, 13.0), respectively, P=0.046]. There were no statistically significant differences in the number of available embryos, available embryo rate, the number of high-quality embryos, high-quality embryo rate, available blastocyst formation rate, fresh cycle clinical pregnancy rate, live birth rate in fresh cycle, cumulative pregnancy rate of frozen embryos with fresh cycle cancellation, CLBR of frozen embryos with fresh cycle cancellation, cumulative clinical pregnancy rate, CLBR, moderate to severe ovarian hyperstimulation syndrome incidence, ectopic pregnancy rate, multiple pregnancy rate and neonatal malformation rate among the three groups (all P>0.05). In terms of economy, the u-FSH group had the lowest total gonadotropin cost for each patient, while the r-FSHα group had the highest. The differences among the three groups were statistically significant [u-FSH group 4 429.08 (3 198.78, 5 044.23) yuan, r-FSHα group 6 023.72 (5 433.75, 7 529.65) yuan, r-FSHβ group 5 480.00 (4 550.90, 6 437.86) yuan, P<0.001]. Binary logistic regression analysis was conducted, using u-FSH as a control. The CLBR of the r-FSHα group and r-FSHβ group showed no statistically significant difference compared with the u-FSH group (a OR=0.95, 95% CI: 0.57-1.58, P=0.838; a OR=0.89, 95% CI: 0.54-1.48, P=0.654). Conclusion:For patients under 35 years old with normal ovarian function undergoing long protocol ovarian stimulation, the effectiveness and safety of the three ovarian-stimulating medicine are similar, but u-FSH has economic advantages.

Objective:To investigate whether malignant tumors affect the laboratory outcomes of patients in their first controlled ovarian hyperstimulation (COH) cycle.Methods:This study was a retrospective case-control study that analyzed the clinical and laboratory data of patients who underwent fertility preservation before chemotherapy and radiotherapy due to malignant tumors, as well as patients with infertility caused by tubal factors who first underwent in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) at the Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University from January 2020 to May 2024. Patients who underwent fertility preservation were designated as the research group, while patients who underwent assisted reproduction due to tubal factors during the same period were designated as control group. After 1∶3 propensity score matching (PSM), 40 patients were included in the research group and 118 patients were included in control group. The ovarian response, oocyte retrieval outcomes, and embryonic development after fertilization in the first COH cycle were compared between the two groups. Results:After PSM, the research group and control group showed statistically significant differences in the gonadotropin (Gn) starting dosage [225.00 (162.50, 300.00) U vs. 193.75 (150.00, 225.00) U, P=0.002], duration of Gn used [10.00 (8.00, 11.00) d vs. 12.00 (10.00, 13.00) d, P<0.001], and average estradiol levels on human chorionic gonadotropin trigger day [2 487.00 (1 461.25, 4 090.25) pmol/L vs. 10 738.50 (8 400.00, 16 507.25) pmol/L, P<0.001]. However, no statistically significant difference was found in the total dosages of Gn used between the two groups ( P>0.05). There were no significant differences between the groups in terms of the number of oocytes retrieved, the number of metaphase Ⅱ oocytes, two pronuclei (2PN) rate, 2PN cleavage rate, available embryo rate, high-quality embryo rate, blastocyst formation rate, and available blastocyst formation rate (all P>0.05). Conclusion:Compared with infertility patients with tubal factors, there is no significant difference in the laboratory outcomes of malignant tumor patients undergoing COH for fertility preservation prior to chemotherapy and radiation.

Objective:To investigate the effects of male body mass index (BMI) on semen parameters and perinatal outcomes following artificial insemination by husband (AIH) treatment.Methods:A retrospective cohort study was conducted to analyze the clinical data of 5 053 patients underwent AIH treatment at the Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University, from January 2017 to February 2024. The study focused on factors such as male semen parameter abnormalities, male sexual dysfunction, female cervical factors, reproductive tract malformations, and unexplained infertility. Patients were classified into three groups based on male BMI: normal weight group (18.5-23.9 kg/m2, n=1 673), overweight group (24.0-27.9 kg/m2, n=2 078), and obese group (BMI≥28.0 kg/m2, n=1 302). The primary objective was to assess the differences in semen parameters and perinatal outcomes among the three groups. Multivariable logistic regression and linear regression analyses were applied to adjust for potential confounders that could influence semen parameters and perinatal outcomes. Results:Semen volume in the normal weight group and overweight group [4.00 (3.00, 5.50) mL, 4.00 (3.00, 5.50) mL] was higher than that in the obese group [4.00 (3.00, 5.00) mL], with a significant difference among the three groups ( P<0.001, a P<0.001). The total sperm count in the normal group and overweight group [207.60 (121.90, 341.75)×10 6, 211.80 (119.88, 334.83)×10 6] was higher than that in the obese group [188.40 (110.96, 323.41)×10 6], with a significant difference among the three groups ( P=0.007, a P<0.001). The total progressive sperm motility count in the normal group [88.18 (43.63, 163.80)×10 6] was higher than that in the obese group [75.30 (40.29, 147.86)×10 6], with a significant difference among the three groups ( P=0.001, a P<0.001). The percentage of forward motile sperm in the normal group [(45.37±17.16)%] was higher than that in the overweight group [(44.03±17.36)%] and the obese group [(43.80±17.21)%], with a significant difference compared among the three groups ( P=0.020, a P=0.016]. In terms of perinatal outcomes, after multivariate logistic regression analysis, only the overweight and obese groups had higher newborn birth weights [(3 389.53±472.65) g, (3 408.57±507.90) g] compared with the normal group [(3 271.32±532.02) g], with a significant difference among the three groups ( P=0.010, a P=0.009). Conclusion:Higher male BMI is associated with decreased semen quality and may increase newborn birth weight following AIH treatment.

Objective:To investigate the association between homocysteine (Hcy) and recurrent pregnancy loss (RPL), as well as its impact on clinical pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET). Methods:This retrospective cohort study collected clinical data from patients undergoing IVF/ICSI-ET at the Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University between December 2020 and March 2024. Patients were divided into no history of pregnancy loss group (named control group, n=1 027) and RPL group ( n=743) based on history of pregnancy loss. Peripheral blood Hcy levels were compared between the two groups. Multivariate logistic regression was performed to adjust for confounding factors and determine whether Hcy is an independent risk factor for RPL. RPL patients were divided into four subgroups based on Hcy quartiles, named Q1 subgroup (Hcy<7.03 μmol/L), Q2 subgroup (7.03 μmol/L≤Hcy<8.63 μmol/L), Q3 subgroup (8.63 μmol/L≤Hcy<10.44 μmol/L), and Q4 subgroup (Hcy≥10.44 μmol/L), to further analyze the impact of Hcy level on pregnancy outcomes after IVF/ICSI-ET in these patients. Results:1) Baseline characteristics between control and RPL groups: statistically significant differences were observed in female age, male age, female body mass index (BMI), duration of infertility, cause of infertility, and peripheral blood Hcy levels (all P<0.05). 2) After adjusting for female age, male age, female BMI, duration of infertility, and cause of infertility via multivariate logistic regression, elevated Hcy levels was identified as an independent risk factor for RPL (a OR=1.366, 95% CI: 1.298-1.438, P<0.001). 3) Baseline characteristics of the four RPL subgroups: antral follicle count (AFC) differed significantly among Q1, Q2, Q3 and Q4 subgroups [17.00 (11.00, 24.00), 15.00 (10.00, 24.00), 14.00 (7.00, 22.25), 15.50 (8.00, 22.00), P=0.043]. No statistically significant differences were observed in other baseline characteristics (all P>0.05). 4) Pregnancy outcomes across the four RPL subgroups: miscarriage rates in the Q1, Q2, Q3 and Q4 subgroups were 18.18% (18/99), 30.61% (30/98), 33.70% (31/92), and 35.96% (32/89), respectively, live birth rates were 44.26% (81/183), 36.17% (68/188), 32.80% (61/186), and 30.65% (57/186), respectively. Intergroup differences in miscarriage rate and live birth rate were statistically significant ( P=0.033, P=0.036). Specifically, miscarriage rate in the Q3 and Q4 subgroups, and live birth rate in the Q4 subgroup were significantly higher than those in the Q1 subgroup (all q<0.05). However, no significant differences were observed in clinical pregnancy rate or early miscarriage rate among the four groups (all P>0.05). After adjusting for confounding factors using multivariate logistic regression, taking the Q1 subgroup as the control, there were no statistically significant differences in the clinical pregnancy rate between the remaining groups and the Q1 subgroup (all P>0.05). The early miscarriage rate in the Q3 subgroup (a OR=2.184, 95% CI: 1.077-4.426, P=0.030) and the early miscarriage rate in the Q4 subgroup (a OR=2.290, 95% CI: 1.116-4.697, P=0.024) were significantly higher than those in the Q1 subgroup; the miscarriage rate in the Q3 subgroup (a OR=2.207, 95% CI: 1.125-4.330, P=0.021) and the miscarriage rate in the Q4 subgroup (a OR=2.377, 95% CI: 1.209-4.674, P=0.012) were significantly higher than those in the Q1 subgroup; the live birth rate in the Q3 subgroup (a OR=0.615, 95% CI: 0.401-0.944, P=0.026) and the live birth rate in the Q4 subgroup (a OR=0.560, 95% CI: 0.364-0.863, P=0.009) were significantly lower than those in the Q1 subgroup. Conclusion:Elevated Hcy is a high-risk factor for RPL in IVF/ICSI-ET patients and may adversely affect pregnancy outcomes.

Objective:To investigate the impact of day 3 embryo quality on pregnancy outcomes in frozen-thawed single blastocyst transfer cycles and analyze its value in embryo selection.Methods:A retrospective cohort study was conducted on clinical data from patients undergoing frozen-thawed single blastocyst transfer at the Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University from January 2020 to December 2023. A total of 4 691 cycles of high-quality day 3 embryo (H-D3) group and 2 598 cycles of low-quality day 3 embryo (L-D3) group in the same period were included. Multivariate logistic regression was used to analyze the effects of day 3 embryo quality on clinical pregnancy rate (CPR) and live birth rate (LBR). All the cycles were stratified according to developmental day and quality of blastocyst: 3 920 cycles of high-quality day 5 blastocysts (H-D5), 1 271 cycles of low-quality day 5 blastocysts (L-D5), 834 cycles of H-D6 group and 1 264 cycles of L-D6, the influence of day 3 embryo quality was subsequently analyzed under different conditions.Results:1) Significant differences were observed between H-D3 and L-D3 groups in female age [(31.79±4.42) years vs. (32.28±4.43) years, P<0.001], basal follicle-stimulating hormone levels [6.24 (5.32,7.35) U/L vs. 6.48 (5.42,7.62) U/L, P<0.001], proportion of primary infertility [35.86% (1 682/4 691) vs. 31.99% (831/2 598), P<0.001], proportion of ≥2 prior failed embryo transfer cycles [3.77% (177/4 691) vs. 5.93% (154/2 598), P<0.001], proportion of gonadotropin-releasing hormone agonist/antagonist controlled ovarian hyperstimulation protocol in fresh cycles [93.33% (4 378/4 691) vs. 89.80%(2 333/2 598), P<0.001], embryo cryopreservation duration [3.10 (2.23,7.27) months vs. 3.60 (2.30,15.40) months, P<0.001], proportion of day 5 blastocyst transfers [74.82% (3 510/4 691) vs. 64.70% (1 681/2 598), P<0.001] and proportion of high-quality blastocyst transfers [72.59% (3 405/4 691) vs. 51.92% (1 349/2 598), P<0.001]. No significant differences were found in body mass index, infertility duration, endometrial preparation program or endometrial thickness on transfer day (all P>0.05). 2) Multivariable logistic regression analysis demonstrated that the L-D3 group had significantly lower CPR ( OR=0.837, 95% CI: 0.754-0.929, P<0.001) and LBR ( OR=0.880, 95% CI: 0.794-0.974, P=0.014) compared with the H-D3 group. 3) In H-D5 and L-D5 cycles, L-D3 did not significantly affect CPR ( aOR=0.941, 95% CI: 0.805-1.101, P=0.449; aOR=0.910, 95% CI: 0.724-1.142, P=0.415) or LBR ( aOR=1.034, 95% CI: 0.893-1.196, P=0.657; aOR=0.917, 95% CI: 0.729-1.153, P=0.457). However, in D6-H and D6-L cycles, L-D3 significantly reduced CPR ( aOR=0.732, 95% CI: 0.542-0.987, P=0.041; aOR=0.648, 95% CI: 0.515-0.815, P<0.001) and LBR ( aOR=0.645, 95% CI: 0.479-0.869, P=0.004; aOR=0.670, 95% CI: 0.526-0.854, P=0.001). Conclusion:Day 3 embryo quality significantly impacts both CPR and LBR in frozen-thawed day 6 single blastocyst transfer cycles. This suggests that day 3 embryo quality retains clinical relevance as a selection criterion when prioritizing day 6 blastocysts for transfer.