This paper systematically elaborates on the key points of diagnosis and differential diagnosis of salivary gland tumors characterized by a substantial amount of extracellular mucus as a main or prominent feature, and clarifies the core differential features. The term "mucus-rich" specifically denotes that mucus is a major component of the tumor, rather than a focal or minor one. This phenomenon is associated with distinct histogenetic mechanisms: it may result from specific genetic mutations (e.g., AKT1 E17K in mucinous adenocarcinoma) that drive ductal epithelial differentiation into mucus-secreting cells, or from myoepithelial cells secreting glycosaminoglycans that form a myxoid stroma. Salivary gland tumors with abundant extracellular mucus include mucinous cystadenoma, sialadenoma papilliferum-like intraductal papillary tumors, mucinous myoepithelioma, pleomorphic adenoma with mucin-rich stroma, mucinous adenocarcinoma, low-grade mucoepidermoid carcinoma, mucin-rich salivary duct carcinoma and intestinal-type adenocarcinoma. The diagnosis of these tumors is complicated by the dual nature of extracellular mucus: while it is a defining feature of some entities, it can also obscure key diagnostic architectural features in others, leading to histological overlap and inconspicuous diagnostic areas. Given the frequent histological morphological overlap among these tumors, immunohistochemical findings and molecular characteristics have emerged as crucial differential diagnostic criteria. Core differential diagnostic points include the following: histologically, there must be meticulous identification of typical structures obscured by mucin (such as squamoid cells in mucoepidermoid carcinoma and apocrine features in salivary duct carcinoma); in immunohistochemical staining, CK20 is useful for distinguishing intestinal-type adenocarcinoma (positive) from mucinous adenocarcinoma (negative), while androgen receptor aids in differentiating salivary duct carcinoma (positive) from mucoepidermoid carcinoma (negative); and molecular testing plays a critical role in definitive diagnosis (e.g., the AKT1 E17K mutation for mucinous adenocarcinoma, MAML2 rearrangement for mucoepidermoid carcinoma, and MEF2C::SS18 fusion for microsecretory adenocarcinoma). This paper systematically summarizes the core pathological features and differential diagnostic points of mucin-rich salivary gland tumors, aiming to provide a practical reference for clinical pathological diagnosis.

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.

Objective:To investigate the status of allostatic load (AL) in patients with polycystic ovary syndrome (PCOS) and its influence on the clinical outcomes of in vitro fertilization-embryo transfer.Methods:This was a prospective study. By using convenient sampling method, 421 patients with PCOS (PCOS group) and 372 control infertility patients (control group) in the Reproductive Center of the First Affiliated Hospital of Anhui Medical University from April 2022 to January 2024 were investigated for basic information, physical examination, laboratory examination and follow-up of clinical outcomes. The total score of AL was calculated using 16 related indicators of cardiovascular system, metabolic system and immune system, and AL>3 was used as the judgment criteria for the high level AL group and the low level AL group. The differences in general data, embryo development and clinical outcomes between the groups were compared.Results:There were 222 cases (52.7%, 222/421) in PCOS low level AL group and 199 cases (47.3%, 199/421) in PCOS high level AL group. There were 214 patients (57.5%, 214/372) in the control low level AL group and 158 patients (42.5%, 158/372) in the control high level AL group. Embryo development outcomes: number of oocytes retrieved (median: 12, 12, 19, 14, respectively; P<0.001), number of two pronuclei (median: 8, 7, 11, 8, respectively; P<0.001), number of fertilization (median: 9, 9, 13, 10, respectively; P<0.001), number of metaphase of meiosis Ⅱ oocytes (median: 9, 8, 13, 10, respectively; P<0.001), number of transferable embryos (median: 5, 5, 7, 6, respectively; P<0.001), number of high-quality embryos (median: 4, 3, 6, 5, respectively; P<0.001), gonadotropin(Gn) starting dosage (median: 150, 200, 150, 200 U, respectively; P<0.001), total dosage of Gn (median: 1 800, 2 075, 1 575, 2 025 U, respectively; P<0.001), duration of Gn used (median: 10, 10, 10, 10 days, respectively; P=0.027) in the control low level AL group, control high level AL group, PCOS low level AL group and PCOS high level AL group were significantly different. Pairings between groups showed that number of oocytes retrieved, number of two pronuclei, number of fertilization, number of metaphase of meiosis Ⅱ oocytes and number of transferable embryos in PCOS high level AL group were lower than those in PCOS low level AL group (all P<0.05); Gn starting dosage and total dosage of Gn in PCOS low level AL group were lower than those in the other three groups (all P<0.05); duration of Gn used in PCOS high level AL group was higher than that PCOS low level AL group ( P<0.05). Clinical outcomes: the control low level AL group, control high level AL group, PCOS low level AL group and PCOS high level AL group underwent fresh transplantation [27.4% (57/208), 24.4% (38/156), 15.1% (32/212), 17.1% (33/193), respectively; P=0.006] and the proportion of transplanted day 5 embryos [82.7% (172/208), 77.6% (121/156), 91.0% (193/212), 86.5% (167/193), respectively; P=0.018] were statistically significant. There were no significant differences in fertilization rate, biochemical pregnancy rate, clinical pregnancy rate, multiple pregnancy rate and early abortion rate among the four groups (all P>0.05). Conclusion:The high level of AL in PCOS patients may affect the outcomes of embryo development, and more attention should be paid to AL in PCOS patients to reduce stress.

Purpose To explore the clinical manifestations,imaging features,and histopathological characteristics of intravascular large B-cell lymphoma(IVL-BCL)involving the central nervous system(CNS).Methods Clinical and imaging data from 5 cases of IVL-BCL were collected.Immunohistochemical staining and FISH were performed to analyze their clinicopathological characteristics,with a comprehensive review of relevant literatures.Results All 5 pa-tients were elderly,with a male-to-female ratio of 4∶1,and an age of onset ranging from 53 to 67 years.The disease course varied from 4 months to 2 years.All patients had varying degrees of neurological damage symptoms.In this study,4 patients experienced varying degrees of weakness in the lower limbs.MRI findings were nonspecific,but all 5 patients showed evidence of cerebrovascular lesions.Histologically,the lesions were characterized by aggregates of lymphoid tumor cells within the lumens of small cerebral vessels,which could obstruct the lumens and cause ischemic and hypoxic changes.Tumor cells did not involve the extravascular brain parenchyma.Immunohistochemically,tumor cells widely expressed mature B-cell markers(CD19,CD20,CD79a,PAX5)with a high Ki67 proliferation index.All 5 patients received systemic chemotherapy after diagnosis,1 patient died,2 patients achieved clinical and physical symptom relief and were still under follow-up.2 patients were undergoing systemic examination before chemotherapy.Conclusion Intravascular large B-cell lymphoma involving the central nervous system is rare,and both clinical mani-festations and imaging examinations lack specific indicators.Preoperative diagnosis is very difficult and can only rely on diagnostic brain biopsy or pathological diagnosis after craniotomy.

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.

Background Prenatal chronic psychological stress may increase the risk of allergic diseases in children, and eczema is the most common allergic disease in children, the pathogenesis of which is not yet fully understood. Objective To preliminarily clarify the changes in offspring intestinal flora after chronic stress exposure during pregnancy in rats that increases offspring immune imbalance and eczema susceptibility. Methods Thirty SPF-grade adult female SD rats were selected and randomly divided into a model group and a control group (n=15). Sixteen male rats were randomly divided into a model mating group and a control mating group (n=8). A 28-day chronic unpredictable mild stress (CUMS) model during pregnancy was established. On the 7th day of stress, male and female rats were caged in a ratio of 3:1. Blood samples were collected from female rats in each group via angular vein on the 1st day before stress, and on the 7th, 14th, 21st, and 28th days after stress. The content of plasma corticosterone during pregnancy was determined by enzyme-linked immunosorbent assay (ELISA). For the offspring rats, an eczema model was constructed using 2,4-dinitrochlorobenzene (DNCB). The number of scratching times of the offspring rats within 5 min was recorded. The offspring rats were divided into 4 groups: DNCB-CUMS group (MM), DNCB-control group (MC), solvent control-CUMS group (CM), and blank control group (CC), with 8 rats in each group. The eczema was induced once every 3 days, and the induction period was 12 d. The expression level of immunoglobulin E (IgE) in the serum of offspring rats after the eczema induction experiment were determined by ELISA. The concentrations of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-2 (IL-2), interleukin-4 (IL-4), and interleukin-13 (IL-13) in the serum were quantified by multi-parameter flow cytometry. The composition and abundance of intestinal microbiota in the feces of offspring rats were detected by 16S rRNA high-throughput sequencing technology. Results The plasma corticosterone concentrations in the model group were higher than those in the control group on the 7th and 21st days of stress (P<0.05). On the 14th and 21st days of stress, the 1% sucrose preference percentages of female rats in the model group were lower than that in the control group. On the 7th, 14th, and 21st days of stress, the horizontal movement scores of female rats in the model group and the vertical movement scores on the 7th and 14th days were lower than those in the control group (P<0.05). After 6, 9, and 12 d of model building, the scratching frequencies in the MC group and MM group were significantly higher than those in the CC group and CM group (P<0.05). Moreover, there were differences in the contents of cytokines including IFN-γ, IL-2, TNF-α, IL-4, IL-13, and IgE among the offspring rat groups (P<0.05). The CM group and MM group led to an increase in the contents of TNF-α, IL-4, IL-13, and IgE cytokines (P<0.05), while the MM group caused a decrease in the contents of IFN-γ and IL-2 (P<0.05). After the eczema induction experiment, the α-diversity analysis showed that the Simpson index and Shannon index in the CM were higher than those in the CC (P<0.05), indicating that CUMS during the pregnancy of female rats could increase the species abundance of their offspring. The abundances of Prevotella and Lactobacillus in the CM group decreased (P<0.05). Conclusion Intestinal dysbiosis in offspring due to chronic prenatal psychological stress, which may be one of the mechanisms linking maternal stress to immune imbalance and increased susceptibility to eczema in offspring.

Purpose To explore the clinical manifestations,imaging features,and histopathological characteristics of intravascular large B-cell lymphoma(IVL-BCL)involving the central nervous system(CNS).Methods Clinical and imaging data from 5 cases of IVL-BCL were collected.Immunohistochemical staining and FISH were performed to analyze their clinicopathological characteristics,with a comprehensive review of relevant literatures.Results All 5 pa-tients were elderly,with a male-to-female ratio of 4∶1,and an age of onset ranging from 53 to 67 years.The disease course varied from 4 months to 2 years.All patients had varying degrees of neurological damage symptoms.In this study,4 patients experienced varying degrees of weakness in the lower limbs.MRI findings were nonspecific,but all 5 patients showed evidence of cerebrovascular lesions.Histologically,the lesions were characterized by aggregates of lymphoid tumor cells within the lumens of small cerebral vessels,which could obstruct the lumens and cause ischemic and hypoxic changes.Tumor cells did not involve the extravascular brain parenchyma.Immunohistochemically,tumor cells widely expressed mature B-cell markers(CD19,CD20,CD79a,PAX5)with a high Ki67 proliferation index.All 5 patients received systemic chemotherapy after diagnosis,1 patient died,2 patients achieved clinical and physical symptom relief and were still under follow-up.2 patients were undergoing systemic examination before chemotherapy.Conclusion Intravascular large B-cell lymphoma involving the central nervous system is rare,and both clinical mani-festations and imaging examinations lack specific indicators.Preoperative diagnosis is very difficult and can only rely on diagnostic brain biopsy or pathological diagnosis after craniotomy.

Objective:To investigate the status of allostatic load (AL) in patients with polycystic ovary syndrome (PCOS) and its influence on the clinical outcomes of in vitro fertilization-embryo transfer.Methods:This was a prospective study. By using convenient sampling method, 421 patients with PCOS (PCOS group) and 372 control infertility patients (control group) in the Reproductive Center of the First Affiliated Hospital of Anhui Medical University from April 2022 to January 2024 were investigated for basic information, physical examination, laboratory examination and follow-up of clinical outcomes. The total score of AL was calculated using 16 related indicators of cardiovascular system, metabolic system and immune system, and AL>3 was used as the judgment criteria for the high level AL group and the low level AL group. The differences in general data, embryo development and clinical outcomes between the groups were compared.Results:There were 222 cases (52.7%, 222/421) in PCOS low level AL group and 199 cases (47.3%, 199/421) in PCOS high level AL group. There were 214 patients (57.5%, 214/372) in the control low level AL group and 158 patients (42.5%, 158/372) in the control high level AL group. Embryo development outcomes: number of oocytes retrieved (median: 12, 12, 19, 14, respectively; P<0.001), number of two pronuclei (median: 8, 7, 11, 8, respectively; P<0.001), number of fertilization (median: 9, 9, 13, 10, respectively; P<0.001), number of metaphase of meiosis Ⅱ oocytes (median: 9, 8, 13, 10, respectively; P<0.001), number of transferable embryos (median: 5, 5, 7, 6, respectively; P<0.001), number of high-quality embryos (median: 4, 3, 6, 5, respectively; P<0.001), gonadotropin(Gn) starting dosage (median: 150, 200, 150, 200 U, respectively; P<0.001), total dosage of Gn (median: 1 800, 2 075, 1 575, 2 025 U, respectively; P<0.001), duration of Gn used (median: 10, 10, 10, 10 days, respectively; P=0.027) in the control low level AL group, control high level AL group, PCOS low level AL group and PCOS high level AL group were significantly different. Pairings between groups showed that number of oocytes retrieved, number of two pronuclei, number of fertilization, number of metaphase of meiosis Ⅱ oocytes and number of transferable embryos in PCOS high level AL group were lower than those in PCOS low level AL group (all P<0.05); Gn starting dosage and total dosage of Gn in PCOS low level AL group were lower than those in the other three groups (all P<0.05); duration of Gn used in PCOS high level AL group was higher than that PCOS low level AL group ( P<0.05). Clinical outcomes: the control low level AL group, control high level AL group, PCOS low level AL group and PCOS high level AL group underwent fresh transplantation [27.4% (57/208), 24.4% (38/156), 15.1% (32/212), 17.1% (33/193), respectively; P=0.006] and the proportion of transplanted day 5 embryos [82.7% (172/208), 77.6% (121/156), 91.0% (193/212), 86.5% (167/193), respectively; P=0.018] were statistically significant. There were no significant differences in fertilization rate, biochemical pregnancy rate, clinical pregnancy rate, multiple pregnancy rate and early abortion rate among the four groups (all P>0.05). Conclusion:The high level of AL in PCOS patients may affect the outcomes of embryo development, and more attention should be paid to AL in PCOS patients to reduce stress.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Objective:To investigate the effect of vitrified oocytes undergoing intracytoplasmic sperm injection (ICSI) on embryo development and transfer outcomes.Methods:A retrospective cohort study was conducted to analyze the clinical data of patients who underwent ICSI in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from October 2015 to December 2022. A total of 95 cycles of vitrified oocytes (named vitrified oocyte group) and 5 830 cycles of fresh oocytes (named fresh oocyte group) in the same period were included, ICSI was used in both groups for fertilization. The cycles were matched at 1∶3 with propensity score matching (PSM), then there was 94 cycles in vitrified oocyte group, 282 cycles in fresh oocyte group. The vitrified oocyte group was dividied into two-step method subgroup and crossed bridge method subgroup according to vitrification procedures. The fertilization, embryo development and clinical pregnancy outcomes were compared between the two groups. Multiple linear regression was used to analyze the correlates affecting oocyte survival rate.Results:After PSM in vitrified oocyte group, the normal fertilization rate [69.59% (572/822)], the normal cleavage rate [95.63% (547/572)], the available embryo rate [74.41% (407/547)], the high-quality embryo rate [36.38% (199/547)], the available blastocyst rate [37.08% (89/240)] and the oocyte utilization rate [37.00% (407/1 100)] were significantly reduced compared with fresh oocyte group [74.26% (1 875/2 525), P=0.009; 97.97% (1 837/1 875), P=0.002; 84.65% (1 555/1 837) , P<0.001; 50.08% (920/1 837), P<0.001; 51.68% (537/1 039), P<0.001; 61.58% (1 555/2 525), P<0.001]. The total fertilization rate, the multiple pronucleus fertilization rate and the oocyte damage rate had no significant differences (all P>0.05). The embryo transfer cycles of vitrified oocyte group had similar implantation rate of cleavage embryos, biochemical pregnancy rate, clinical pregnancy rate and early abortion rate compared with fresh oocyte group (all P>0.05), however the number of cleavage embryo transfer was significantly increased (1.91±0.28 vs. 1.72±0.45, P=0.001), the late abortion rate was also significantly increased [10.53% (4/38) vs. 1.14% (1/88), P=0.048]. Between two-step method and crossed bridge method subgroups, there were significant differences in oocyte survival rate [55.95% (188/336) vs. 82.98% (634/764), P<0.001], oocyte damage rate [6.38% (12/188) vs. 3.00% (19/634), P=0.032], available blastocyst rate [5.08% (13/59) vs. 41.99% (76/181), P=0.006] and oocyte utilization rate [26.49% (89/336) vs. 41.62% (318/764), P<0.001], there were no significant differences in total fertilization rate, normal fertilization rate, multiple pronucleus fertilization rate, normal cleavage rate, available embryo rate and high-quality embryo rate (all P>0.05). Multiple linear regression analysis showed that controlled ovarian stimulation procedure ( β=-19.730, t=-2.06, P=0.043), number of vitrified oocytes ( β=-1.417, t=-3.10, P=0.003) and procedure of oocytes vitrfication ( β=33.872, t=5.04, P<0.001) had a statistical effect on oocyte survival rate. Conclusion:Vitrification of oocytes has a negative effect on embryo development, the pregnancy outcomes after embryo transfer is similar to fresh oocytes, the perinatal safety remains to be confirmed by further studied.