PURPOSE: To compare the effects of empirical and modified hemostatic resuscitation for liver blast injury combined with seawater immersion. METHODS: Thirty rabbits were subjected to liver blast injury combined with seawater immersion, and were then divided into 3 groups randomly (n = 10 each): group A (no treatment after immersion), group B (empirical resuscitation with 20 mL hydroxyethyl starch, 50 mg tranexamic acid, 25 IU prothrombin complex concentrate and 50 mg/kg body weight fibrinogen concentrate), and group C (modified resuscitation with additional 10 IU prothrombin complex concentrate and 20 mg/kg body weight fibrinogen concentrate based on group B). Blood samples were gathered at specified moments for assessment of thromboelastography, routine coagulation test, and biochemistry. Mean arterial pressure, heart rate, and survival rate were also documented at each time point. The Kolmogorov-Smirnov test was used to examine the normality of data distribution. Multigroup comparisons were conducted with one-way ANOVA. RESULTS: Liver blast injury combined with seawater immersion resulted in severe coagulo-fibrinolytic derangement as indicated by prolonged prothrombin time (s) (11.53 ± 0.98 vs. 7.61 ± 0.28, p＜0.001), activated partial thromboplastin time (APTT) (s) (33.48 ± 6.66 vs. 18.23 ± 0.89, p＜0.001), reaction time (R) (min) (5.85 ± 0.96 vs. 2.47 ± 0.53, p＜0.001), decreased maximum amplitude (MA) (mm) (53.20 ± 5.99 vs. 74.92 ± 5.76, p＜0.001) and fibrinogen concentration (g/L) (1.19 ± 0.29 vs. 1.89 ± 0.32, p = 0.003), and increased D-dimer concentration (mg/L) (0.38 ± 0.32 vs. 0.05 ± 0.03, p = 0.005). Both empirical and modified hemostatic resuscitation could improve the coagulo-fibrinolytic states and organ function, as indicated by shortened APTT and R values, decreased D-dimer concentration, increased fibrinogen concentration and MA values, lower concentration of blood urea nitrogen and creatine kinase-MB in group B and group C rabbits in comparison to that observed in group A. Further analysis found that the R values (min) (4.67 ± 0.84 vs. 3.66 ± 0.98, p = 0.038), APTT (s) (23.16 ± 2.75 vs. 18.94 ± 1.05, p = 0.001), MA (mm) (60.10 ± 4.74 vs. 70.21 ± 3.01, p < 0.001), and fibrinogen concentration (g/L) (1.68 ± 0.21 vs. 1.94 ± 0.16, p = 0.013) were remarkably improved in group C than in group B at 2 h and 4 h after injury. In addition, the concentration of blood urea nitrogen (mmol/L) (24.11 ± 1.96 vs. 21.00 ± 3.78, p = 0.047) and creatine kinase-MB (U/L) (85.50 ± 13.60 vs. 69.74 ± 8.56, p = 0.013) were lower in group C than in group B at 6 h after injury. The survival rates in group B and group C were significantly higher than those in group A at 4 h and 6 h after injury (p < 0.001), however, there were no statistical differences in survival rates between group B and group C at each time point. CONCLUSIONS Modified hemostatic resuscitation could improve the coagulation parameters and organ function better than empirical hemostatic resuscitation.
Animals ; Rabbits ; Resuscitation/methods* ; Liver/injuries* ; Seawater ; Blast Injuries/therapy* ; Fibrinogen/administration & dosage* ; Male ; Tranexamic Acid/administration & dosage* ; Immersion ; Hydroxyethyl Starch Derivatives/administration & dosage*

PURPOSE: To construct a decision-making app for pre-hospital damage control resuscitation (PHDCR) for severely injured patients, and to make a preliminary trial test on the effectiveness and usability aspects of the constructed app. METHODS: Decision-making algorithms were first established by a thorough literature review, and were then used to be learned by computer with 3 kinds of text segmentation algorithms, i.e., dictionary-based segmentation, machine learning algorithms based on labeling, and deep learning algorithms based on understanding. B/S architecture mode and Spring Boot were used as a framework to construct the app. A total of 16 Grade-5 medical students were recruited to test the effectiveness and usability aspects of the app by using an animal model-based test on simulated PHDCR. Twelve adult Bama miniature pigs were subjected to penetrating abdominal injuries and were randomly assigned to the 16 students, who were randomly divided into 2 groups (n = 8 each): group A (decided on PHDCR by themselves) and group B (decided on PHDCR with the aid of the app). The students were asked to complete the PHDCR within 1 h, and then blood samples were taken and thromboelastography, routine coagulation test, blood cell count, and blood gas analysis were examined. The lab examination results along with the value of mean arterial pressure were used to compare the resuscitation effects between the 2 groups. Furthermore, a 4-statement-based post-test survey on a 5-point Likert scale was performed in group B students to test the usability aspects of the constructed app. RESULTS: With the above 3 kinds of text segmentation algorithm, B/S architecture mode, and Spring Boot as the development framework, the decision-making app for PHDCR was successfully constructed. The time to decide PHDCR was (28.8 ± 3.41) sec in group B, much shorter than that in group A (87.5 ± 8.53) sec (p < 0.001). The outcomes of animals treated by group B students were much better than that by group A students as indicated by higher mean arterial pressure, oxygen saturation and fibrinogen concentration and maximum amplitude, and lower R values in group B than those in group A. The post-test survey revealed that group B students gave a mean score of no less than 4 for all 4 statements. CONCLUSION A decision-making app for PHDCR was constructed in the present study and the preliminary trial test revealed that it could help to improve the resuscitation effect in animal models of penetrating abdominal injury.
Animals ; Swine ; Resuscitation/methods* ; Mobile Applications ; Humans ; Algorithms ; Emergency Medical Services/methods* ; Male ; Decision Making ; Female

Objective To evaluate the resuscitation efficacy of novel lyophilized platelets(LP,thrombin-stimulated platelets)combined with lactated Ringer's(LR)solution in rabbits with hemorrhagic shock and seawater immersion.Methods Fifty rabbits were randomly assigned to 5 groups(Groups A,B,C,D and E,n=10).After all rabbits were anesthetized with 3%pentobarbital sodium at a dose of 1 mL/kg,soft tissue injury was inflicted in the left lower limb.The blood loss from the soft tissue injury was quantified after gauze hemostasis.The right lower limb was subjected to femoral artery catheterization,followed by blood withdrawal equivalent to 26%of the total blood volume of the rabbit.The rabbits were then vertically immersed in 3%artificial seawater,with the water level reaching above the xiphoid process,and were retrieved in 15 min later.Resuscitation strategies were applied to the rabbits from different group:Group A(no resuscitation),Group B(resuscitation with LR solution),Group C(resuscitation with LR solution and fresh platelets),Group D(resuscitation with LR solution and LP),and Group E(resuscitation with LR solution and novel LP).Coagulation function test,routine blood test,blood gas analysis,and thromboelastography were conducted at baseline and at 1,2 and 4 h after injury.Results The LP and rabbit model of hemorrhagic shock and seawater immersion were successfully prepared.At 1 h after injury,the mean arterial pressure(MAP)of Groups C,D and E(infused with platelet preparations)was significantly higher than that of Group A(without resuscitation,P<0.05);the lactate(Lac)content of Group C was obviously lower than that of Groups A and B(P<0.05);the base excess(BE)and blood urea nitrogen(BUN)levels of Groups C,D and E were notably lower than those of Groups A and B(P<0.05);and the prothrombin time(PT)of Group A was significantly longer than that of before injury(P<0.05).At 2 h after injury,the MAP of Groups C and D was significantly higher than that of Groups A and B,and that of Group E was notably higher than that of Group A(P<0.05);the Lac content of Groups C and E was obviously lower than that of Groups A and B,while that of Group D was also lower than that of Group A(P<0.05);the BE and BUN levels of Groups C,D and E were remarkably lower than those of Groups A and B(P<0.05);the maximum amplitude(MA)value of Group C was higher than that of Group A,while the value of Groups A and D at this time was significantly lower than the corresponding value before injury(P<0.05);and the activated partial clotting time(APTT)of Groups A and D was statistically longer than the corresponding baseline time(P<0.05).At 4 h after injury,the MAP of Groups C,D,and E was higher than that of Groups A and B,and that of Group B was higher than that of Group A(P<0.05);the Lac and BUN levels of Groups C,D,and E were lower than those of Groups A and B(P<0.05);the BE level of Groups C and D were lower than those of Groups A and B(P<0.05);the MA value of Groups B,C,and E were higher than those of Group A(P<0.05),while the MA value and APTT value of Groups A and D were significantly lower than their corresponding baseline values(P<0.05).Conclusion For rabbits with hemorrhagic shock and seawater immersion,the novel LP combined with LR solution can significantly increase the MAP level,reduce Lac content,and sustainably maintain blood clot firmness and coagulation function.

With advancements in in vitro culture techniques, the morula has emerged as a promising candidate for selective embryo transfer due to its critical compaction phase. The compaction process involves not only structural reorganization but also complex intercellular signaling mechanisms that significantly influence embryonic developmental potential and cellular fate determination. Clinical data reveal comparable live birth rates between day 4 morula transfers and day 5 blastocyst transfers, coupled with reduced in vitro culture duration. However, challenges persist regarding standardized evaluation criteria and long-term safety confirmation. Current morphological assessment methods exhibit inherent subjectivity, while emerging technologies integrating genetic screening, metabolic analysis, and time-lapse imaging show potential for enhanced selection accuracy. Personalized synchronization assessments, including endometrial receptivity analysis, may further optimize transfer protocols. This study focuses on day 4 embryo transfer, systematically reviewing its embryonic development processes, evaluation protocols, comparative outcomes of transferred embryos, and research advances in frozen-thawed embryo transfer. The study aims to deepen scientific understanding of day 4 embryo transfer and promote its adoption as a critical option in personalized reproductive medicine, thereby enhancing clinical success rates and safety.

Objective:To establish a day 4 embryo evaluation protocol by analyzing embryonic characteristics affecting blastocyst formation, and validate its clinical effectiveness.Methods:This retrospective cohort study included clinical data from 1 037 patients who underwent fresh in vitro fertilization and embryo transfer (IVF-ET) on day 4 in Center for Reproductive Medicine of Xingtai Meihe Reproductive and Genetic Hospital between January 2018 and April 2024. Morphological assessments were performed at (92±2) h post-fertilization. After excluding 1 326 embryos selected for fresh transfer, 2 723 embryos underwent blastocyst culture. To address selection bias in transferred embryos, the scoring system was primarily based on high-quality blastocyst formation rates. Multivariate binary regression analysis evaluated how day 4 developmental stage, fragmentation rate, stage-specific cleavage patterns, multinucleation/vacuolization affected transferable blastocyst formation rate and high-quality blastocyst rate. Regression coefficients determined parameter weights for high-quality blastocyst formation, establishing a day 4 embryo scoring protocol that compared outcomes across different grades. The scoring system was validated by comparing transferable blastocyst formation rate, high-quality blastocyst rate, and implantation rate among different day 4 embryo grades. All embryos were further rescored according to three previously reported evaluation schemes [Feil 2008, Gemma 2015, and European Society of Human Reproduction and Embryology (ESHRE) 2011]. The predictive values of these three day 4 scoring systems and the day 4 scoring system established in this study were compared using the area under the curve (AUC) receiver operating characteristic (ROC) curve in predicting the formation rate of transferable blastocyst, the formation rate of high-quality blastocyst, and implantation rate. Results:In the prediction of high-quality blastocyst formation, early blastocyst showed the highest influence weight compared to embryos with the ratio of blastomere numbers on day 4 to those on day 3 (BNR) <1.2 ( B=3.398, OR=29.915, P<0.001), followed by fragmentation <10% versus ≥50% ( B=1.263, OR=3.535, P<0.001), a stage-specific cleavage pattern ( B=0.903, OR=2.467, P=0.005), and absence of multinucleation or vacuoles ( B=0.797, OR=2.218, P=0.007). Using the newly developed day 4 scoring system, embryos were graded A, B, C, D, E. Transferable blastocyst formation rates were 88.57% (279/315), 76.99% (241/313), 56.11% (280/499), 40.27% (238/591) and 14.22% (143/1 005), respectively; high-quality blastocyst rates were 51.42% (162/315), 35.46% (111/313), 20.04% (100/499), 9.47% (56/591) and 3.98% (40/1 005). All inter-group differences were statistically significant (all P<0.005). Implantation rates for transferred embryos of grades A-E declined sequentially: 63.18% (381/603), 56.19% (322/573), 38.29% (54/141), 26.53% (13/49) and 9.67% (3/31). The day 4 embryo scoring system proposed in this study demonstrated significantly higher predictive efficacy for transferable blastocyst formation rate (AUC=0.812), high-quality blastocyst formation rate (AUC=0.804), and implantation rate (AUC=0.603) compared with Feil 2008 (AUC=0.797, P<0.001; AUC=0.781, P<0.001; AUC=0.585, P<0.001), Gemma 2015 (AUC=0.773, P<0.001; AUC=0.771, P<0.001; AUC=0.542, P=0.006), and ESHRE 2011 (AUC=0.710, P<0.001; AUC=0.745, P<0.001; AUC=0.592, P<0.001). We also observed the presence of pseudo-compacted embryo, whose transferable blastocyst formation rate [38.28% (49/128)] and high-quality blastocyst formation rate [7.03% (9/128)] were similar to those of cleavage-stage embryos with a BNR≥1.2. Conclusion:The established day 4 morphological assessment system reliably predicts the potential to transferable blastocyst and high-quality blastocyst, and effectively forecasts implantation rates.

With advancements in in vitro culture techniques, the morula has emerged as a promising candidate for selective embryo transfer due to its critical compaction phase. The compaction process involves not only structural reorganization but also complex intercellular signaling mechanisms that significantly influence embryonic developmental potential and cellular fate determination. Clinical data reveal comparable live birth rates between day 4 morula transfers and day 5 blastocyst transfers, coupled with reduced in vitro culture duration. However, challenges persist regarding standardized evaluation criteria and long-term safety confirmation. Current morphological assessment methods exhibit inherent subjectivity, while emerging technologies integrating genetic screening, metabolic analysis, and time-lapse imaging show potential for enhanced selection accuracy. Personalized synchronization assessments, including endometrial receptivity analysis, may further optimize transfer protocols. This study focuses on day 4 embryo transfer, systematically reviewing its embryonic development processes, evaluation protocols, comparative outcomes of transferred embryos, and research advances in frozen-thawed embryo transfer. The study aims to deepen scientific understanding of day 4 embryo transfer and promote its adoption as a critical option in personalized reproductive medicine, thereby enhancing clinical success rates and safety.

Objective:To establish a day 4 embryo evaluation protocol by analyzing embryonic characteristics affecting blastocyst formation, and validate its clinical effectiveness.Methods:This retrospective cohort study included clinical data from 1 037 patients who underwent fresh in vitro fertilization and embryo transfer (IVF-ET) on day 4 in Center for Reproductive Medicine of Xingtai Meihe Reproductive and Genetic Hospital between January 2018 and April 2024. Morphological assessments were performed at (92±2) h post-fertilization. After excluding 1 326 embryos selected for fresh transfer, 2 723 embryos underwent blastocyst culture. To address selection bias in transferred embryos, the scoring system was primarily based on high-quality blastocyst formation rates. Multivariate binary regression analysis evaluated how day 4 developmental stage, fragmentation rate, stage-specific cleavage patterns, multinucleation/vacuolization affected transferable blastocyst formation rate and high-quality blastocyst rate. Regression coefficients determined parameter weights for high-quality blastocyst formation, establishing a day 4 embryo scoring protocol that compared outcomes across different grades. The scoring system was validated by comparing transferable blastocyst formation rate, high-quality blastocyst rate, and implantation rate among different day 4 embryo grades. All embryos were further rescored according to three previously reported evaluation schemes [Feil 2008, Gemma 2015, and European Society of Human Reproduction and Embryology (ESHRE) 2011]. The predictive values of these three day 4 scoring systems and the day 4 scoring system established in this study were compared using the area under the curve (AUC) receiver operating characteristic (ROC) curve in predicting the formation rate of transferable blastocyst, the formation rate of high-quality blastocyst, and implantation rate. Results:In the prediction of high-quality blastocyst formation, early blastocyst showed the highest influence weight compared to embryos with the ratio of blastomere numbers on day 4 to those on day 3 (BNR) <1.2 ( B=3.398, OR=29.915, P<0.001), followed by fragmentation <10% versus ≥50% ( B=1.263, OR=3.535, P<0.001), a stage-specific cleavage pattern ( B=0.903, OR=2.467, P=0.005), and absence of multinucleation or vacuoles ( B=0.797, OR=2.218, P=0.007). Using the newly developed day 4 scoring system, embryos were graded A, B, C, D, E. Transferable blastocyst formation rates were 88.57% (279/315), 76.99% (241/313), 56.11% (280/499), 40.27% (238/591) and 14.22% (143/1 005), respectively; high-quality blastocyst rates were 51.42% (162/315), 35.46% (111/313), 20.04% (100/499), 9.47% (56/591) and 3.98% (40/1 005). All inter-group differences were statistically significant (all P<0.005). Implantation rates for transferred embryos of grades A-E declined sequentially: 63.18% (381/603), 56.19% (322/573), 38.29% (54/141), 26.53% (13/49) and 9.67% (3/31). The day 4 embryo scoring system proposed in this study demonstrated significantly higher predictive efficacy for transferable blastocyst formation rate (AUC=0.812), high-quality blastocyst formation rate (AUC=0.804), and implantation rate (AUC=0.603) compared with Feil 2008 (AUC=0.797, P<0.001; AUC=0.781, P<0.001; AUC=0.585, P<0.001), Gemma 2015 (AUC=0.773, P<0.001; AUC=0.771, P<0.001; AUC=0.542, P=0.006), and ESHRE 2011 (AUC=0.710, P<0.001; AUC=0.745, P<0.001; AUC=0.592, P<0.001). We also observed the presence of pseudo-compacted embryo, whose transferable blastocyst formation rate [38.28% (49/128)] and high-quality blastocyst formation rate [7.03% (9/128)] were similar to those of cleavage-stage embryos with a BNR≥1.2. Conclusion:The established day 4 morphological assessment system reliably predicts the potential to transferable blastocyst and high-quality blastocyst, and effectively forecasts implantation rates.

Objective:To explore the effect of different transplantation schemes on the clinical outcomes and maternal and fetal outcomes of fresh cycle on day 4.Methods:The clinical data of 745 cycles of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in Reproductive Medicine Center of Xingtai Infertility Specialist Hospitals from January 2019 to December 2021 were analyzed retrospectively. In all cycles, 1-2 embryos were transferred on day 4 after fertilization. According to different embryo transfer schemes, they were divided into five groups: one partial compaction embryo group (group A, n=17), two partial compaction embryos group (group B, n=236), one full compaction above embryo group (group C, n=241), partial compaction+full compaction above group (group D, n=72), and two full compaction above embryos group (group E, n=179), the effects of different transfer schemes on clinical outcomes and maternal and fetal outcomes were compared. Results:There were no significant differences in two pronuclei (2PN) fertilization rate, 2PN cleavage rate, endometrial thickness, monozygotic twins rate, surgical reduction rate, abortion rate, stillbirth rate, cesarean section rate, male infant/female infant ratio among the five groups (all P>0.05). The clinical pregnancy rate in groups D and E [83.33% (60/72), 72.63% (130/179)] was significantly higher than that in group B [59.32% (140/236), P<0.001, P=0.005]. The live birth rate of group E [65.36% (117/179)] was significantly higher than that of group B [50.00% (118/236), P=0.002]. The implantation rate of groups C, D and E [64.73% (156/241),59.72% (86/144), 54.19% (194/358)] was significantly higher than that of group B [39.83% (188/472), all P<0.001]. The multiple birth rate [43.33% (26/60), 49.23% (64/130)] and the premature delivery rate [23.33% (14/60), 26.15% (34/130)] in groups D and E were significantly higher than those in group C [0%, all P<0.001; 7.69% (12/156), P=0.002, P<0.001]. The gestational weeks of delivery in group E [38.0 (36.0,39.0) weeks] was significantly lower than that in group C [39.0 (38.0,39.3) weeks, P<0.001]. Compared with the one embryo transfer group (group A, group C), the birth weight of the two embryos transfer group (group B, group D, group E) was significantly lower ( P<0.001). The low birth weight infants rate in group D [20.90% (14/67)] and group E [28.40% (48/169)] was significantly higher than that in group C [3.85% (5/130), P<0.001]. Logistic regression analysis showed that after adjusted, the pregnancy rate in group C was significantly higher than that in group A ( OR=0.353, 95% CI: 0.125-0.997, P=0.049). The live birth rate of group E was significantly higher than that of group C ( OR=1.842, 95% CI: 1.172-2.895, P=0.008), and the premature delivery rate of groups B, D and E was significantly higher than that of group C ( OR=2.546, 95% CI: 1.079-6.005, P=0.033; OR=6.737, 95% CI: 2.566-17.689, P<0.001; OR=5.863, 95% CI: 2.494-13.785, P<0.001). Conclusion:On day 4 of the fresh cycle, the pregnancy rate and the live birth rate of the full compaction or above embryos are significantly higher than those of the partial compaction embryos. In clinical work, it is recommended to select full compaction embryos or above, and then select partially compaction embryos for single embryo transfer to achieve optimal pregnancy outcomes while reducing the multiple pregnancy rate, premature delivery rate, and low birth weight infant rate.

Objective:To investigate the effects of day 4 (D4) embryo transfer on clinical outcomes and maternal and infant outcomes in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in fresh cycles. Methods:We retrospectively analyzed the clinical data of 361 IVF and ICSI cycles from January 2019 to December 2021 in the Reproductive Medicine Center of Xingtai Infertility Specialist Hospitals in a cohort study. In all cycles, one of the best quality embryo was transferred at D4 or D5 after fertilization. The clinical outcomes and maternal and fetal outcomes of D4 transfer group and D5 transfer group were compared.Results:Compared with D4 transfer group, the estradiol value on human chorionic gonadotropin (hCG) injection day significantly increased in D5 transfer group [3 516 (2 273, 4 116) ng/L vs. 2 940 (1 935, 3 877) ng/L, P=0.023], and the luteinizing hormone (LH) value on hCG injection day significantly decreased [0.82 (0.63, 1.11) μg/L vs. 0.94 (0.69, 1.20) μg/L, P=0.026], two pronuclei (2PN) fertilization rate [71.13% (929/1 306)] and the available embryo rate [51.73% (509/984)] in D5 transfer group were significantly higher than those in D4 transfer group [67.26% (2 539/3 775), P=0.010; 48.00% (1 306/2 721), P=0.045]. The clinical pregnancy rate [63.37% (173/273)] and the live birth rate [53.11% (145/273)] in D4 transfer group were significantly higher than those in D5 transfer group [46.59% (41/88), P=0.005; 36.36% (32/88), P=0.006]. There were no significant differences in ectopic pregnancy rate, monozygotic twins rate, abortion rate, preterm birth rate, stillbirth rate, caesarean section rate, delivery gestation, male/female ratio and birth weight (all P>0.05). The results of logistic regression analysis showed that the days of embryo transfer had a significant correlation with the pregnancy rate and the live birth rate ( OR=0.468, 95% CI: 0.266-0.824, P=0.009; OR=0.481, 95% CI: 0.273-0.847, P=0.011). Conclusion:In IVF/ICSI of fresh cycles, the clinical pregnancy rate and the live birth rate of D4 transplantation are better than that of D5 transplantation, and the maternal and fetal outcomes are similar. Therefore, D4 embryo transplantation can be preferred in clinical work.

Objective:To explore the effect of different transplantation schemes on the clinical outcomes and maternal and fetal outcomes of fresh cycle on day 4.Methods:The clinical data of 745 cycles of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in Reproductive Medicine Center of Xingtai Infertility Specialist Hospitals from January 2019 to December 2021 were analyzed retrospectively. In all cycles, 1-2 embryos were transferred on day 4 after fertilization. According to different embryo transfer schemes, they were divided into five groups: one partial compaction embryo group (group A, n=17), two partial compaction embryos group (group B, n=236), one full compaction above embryo group (group C, n=241), partial compaction+full compaction above group (group D, n=72), and two full compaction above embryos group (group E, n=179), the effects of different transfer schemes on clinical outcomes and maternal and fetal outcomes were compared. Results:There were no significant differences in two pronuclei (2PN) fertilization rate, 2PN cleavage rate, endometrial thickness, monozygotic twins rate, surgical reduction rate, abortion rate, stillbirth rate, cesarean section rate, male infant/female infant ratio among the five groups (all P>0.05). The clinical pregnancy rate in groups D and E [83.33% (60/72), 72.63% (130/179)] was significantly higher than that in group B [59.32% (140/236), P<0.001, P=0.005]. The live birth rate of group E [65.36% (117/179)] was significantly higher than that of group B [50.00% (118/236), P=0.002]. The implantation rate of groups C, D and E [64.73% (156/241),59.72% (86/144), 54.19% (194/358)] was significantly higher than that of group B [39.83% (188/472), all P<0.001]. The multiple birth rate [43.33% (26/60), 49.23% (64/130)] and the premature delivery rate [23.33% (14/60), 26.15% (34/130)] in groups D and E were significantly higher than those in group C [0%, all P<0.001; 7.69% (12/156), P=0.002, P<0.001]. The gestational weeks of delivery in group E [38.0 (36.0,39.0) weeks] was significantly lower than that in group C [39.0 (38.0,39.3) weeks, P<0.001]. Compared with the one embryo transfer group (group A, group C), the birth weight of the two embryos transfer group (group B, group D, group E) was significantly lower ( P<0.001). The low birth weight infants rate in group D [20.90% (14/67)] and group E [28.40% (48/169)] was significantly higher than that in group C [3.85% (5/130), P<0.001]. Logistic regression analysis showed that after adjusted, the pregnancy rate in group C was significantly higher than that in group A ( OR=0.353, 95% CI: 0.125-0.997, P=0.049). The live birth rate of group E was significantly higher than that of group C ( OR=1.842, 95% CI: 1.172-2.895, P=0.008), and the premature delivery rate of groups B, D and E was significantly higher than that of group C ( OR=2.546, 95% CI: 1.079-6.005, P=0.033; OR=6.737, 95% CI: 2.566-17.689, P<0.001; OR=5.863, 95% CI: 2.494-13.785, P<0.001). Conclusion:On day 4 of the fresh cycle, the pregnancy rate and the live birth rate of the full compaction or above embryos are significantly higher than those of the partial compaction embryos. In clinical work, it is recommended to select full compaction embryos or above, and then select partially compaction embryos for single embryo transfer to achieve optimal pregnancy outcomes while reducing the multiple pregnancy rate, premature delivery rate, and low birth weight infant rate.