Objective:To investigate the effect of luteinizing hormone (LH) levels on the clinical outcome and cumulative live birth rate of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) fresh embryo transfer in patients with normal ovarian reserve function after application of a flexible protocol of gonadotropin-releasing hormone antagonist (GnRH-A) to promote ovulation with the addition of GnRH-A. Methods:A retrospective cohort study was conducted to analyze the data of 685 patients with normal ovarian reserve function who underwent IVF/ICSI after ovulation induction with antagonist flexible regimen between January 2016 and June 2021 at the Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University. The quartile method was used to group patients after the addition of the antagonist by the mean value of serum LH each time they were monitored (usually twice, depending on the rate of follicular growth and patients' need) until the day of the trigger, and were divided into group A (smaller than the 25th percentile of the mean LH level of the included population, LH<1.25 U/L, n=166), group B (in the 25th to 50th percentile of the mean LH level of the included population, 1.25 U/L≤LH<1.91 U/L, n=174), group C (in the 50th to 75th percentile of the mean LH level of the included population, 1.91 U/L≤LH<2.85 U/L, n=171), and group D (greater than the 75th percentile of the mean LH level of the included population, 2.85 U/L≤LH≤7.55 U/L, n=174). The general condition, clinical data, embryo laboratory indices, clinical outcome indices of fresh embryo transfer cycle and cumulative live birth rate were compared among the 4 groups. Results:After correcting for confounding factors by multifactorial linear regression, the number of high-quality embryos and the rate of blastocyst formation of patients in group C were significantly higher than those in group A, and the differences were statistically significant ( B=0.600, 95% CI: 0.086-1.114, P=0.022; B=0.134, 95% CI: 0.052-0.216, P=0.001). The number of high-quality embryos, the number of available embryos, and the rate of blastocyst formation of patients in group D were significantly higher than those in group A, and the differences were statistically significant ( B=0.771, 95% CI: 0.259-1.284, P=0.003; B=0.730, 95% CI: 0.205-1.255, P=0.007; B=0.085, 95% CI: 0.003-0.167, P=0.042).After multifactorial logistic regression, there was no statistically significant difference in live birth rate between group A and groups B, C and D ( P>0.05). The cumulative live birth rate of patients in group D was significantly higher than that in group A, and the difference was statistically significant ( aOR=2.439, 95% CI: 1.169-4.974, P=0.014). Conclusion:In patients with normal ovarian reserve function, a flexible protocol of antagonists was applied to promote ovulation, and the addition of antagonists had no significant effect on the clinical outcome of the fresh embryo transfer cycle in terms of mean LH levels, but the quality of the embryos was significantly reduced when the mean LH level was <1.25 U/L, and this may consequently reduce the developmental potential of the embryos and the cumulative live birth rate.

Objective:To explore the effect of vaginal microbiota disorder on pregnancy outcomes in the first-time frozen-thawed embryo transfer (FET) patients and perinatal outcomes in single pregnancy live delivery patients.Methods:The clinical data of 2 299 cycles of FET patients in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2021 to December 2022 were collected in a retrospective cohort study. According to the types of dominant bacteria in the vaginal microbiota before transplantation, they were divided into three groups: control group (dominant bacteria were Lactobacillus, which was Gram positive bacteria, 1 849 cycles), the Gram negative bacilli group (191 cycles), and the Gram positive cocci group (259 cycles). Baseline data and pregnancy outcomes were compared among the three groups. The perinatal outcomes of select single pregnancy live birth FET patients who met the inclusion criteria were further analyzed among the three groups. The main observation indicators were live birth rate, miscarriage rate, and preterm birth rate. A multivariate logistic regression model was used to control confounding factors in the main observation indicators, and to analyze the relationship between dominant bacterial types in the vaginal microbiota and live birth rate, miscarriage rate, and preterm birth rate.Results:The difference in endometrial thickness on the day of transplantation among control group, Gram negative bacilli group, and Gram positive cocci group was statistically significant [(9.38±1.58) mm, (9.56±1.70) mm, and (9.84±1.74) mm, respectively, P<0.001]. In the endometrium preparation methods, the proportion of down-regulation+artificial cycle patients in the Gram positive cocci group was higher than that in control group, and the difference was statistically significant [13.13% (34/259) and 7.46% (138/1 849), respectively, P<0.016 7]. In the pregnancy outcomes, there was a statistically significant difference in live birth rate among control group, Gram negative bacilli group, and Gram positive cocci group [49.86% (922/1 849), 49.21% (94/191) and 41.70% (108/259), respectively, P=0.048]. The live birth rate of the Gram positive cocci group was lower than that of control group, and the difference between the two groups was statistically significant ( P<0.016 7). There were no statistically significant differences in other pregnancy outcomes and perinatal outcomes of single pregnancy live birth FET patients (all P>0.05). The multivariate logistic regression model corrected for female age, infertility years, basal follicle stimulating hormone, anti-Müllerian hormone, proportion of single embryo transfer, proportion of single blastocyst transfer, endometrial thickness on transfer day, and endometrial preparation methods, Gram positive cocci were independent risk factors for live brith after FET transplantation (a OR=0.73, 95% CI: 0.55-0.95, P=0.021). Conclusion:The dominant bacteria in the vaginal microbiota before embryo transfer are Gram positive cocci, which may be related to a decrease in live birth rate in first-time FET patients, but not significantly related to the perinatal outcomes.

Objective:To investigate the effect of luteinizing hormone (LH) levels on the clinical outcome and cumulative live birth rate of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) fresh embryo transfer in patients with normal ovarian reserve function after application of a flexible protocol of gonadotropin-releasing hormone antagonist (GnRH-A) to promote ovulation with the addition of GnRH-A. Methods:A retrospective cohort study was conducted to analyze the data of 685 patients with normal ovarian reserve function who underwent IVF/ICSI after ovulation induction with antagonist flexible regimen between January 2016 and June 2021 at the Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University. The quartile method was used to group patients after the addition of the antagonist by the mean value of serum LH each time they were monitored (usually twice, depending on the rate of follicular growth and patients' need) until the day of the trigger, and were divided into group A (smaller than the 25th percentile of the mean LH level of the included population, LH<1.25 U/L, n=166), group B (in the 25th to 50th percentile of the mean LH level of the included population, 1.25 U/L≤LH<1.91 U/L, n=174), group C (in the 50th to 75th percentile of the mean LH level of the included population, 1.91 U/L≤LH<2.85 U/L, n=171), and group D (greater than the 75th percentile of the mean LH level of the included population, 2.85 U/L≤LH≤7.55 U/L, n=174). The general condition, clinical data, embryo laboratory indices, clinical outcome indices of fresh embryo transfer cycle and cumulative live birth rate were compared among the 4 groups. Results:After correcting for confounding factors by multifactorial linear regression, the number of high-quality embryos and the rate of blastocyst formation of patients in group C were significantly higher than those in group A, and the differences were statistically significant ( B=0.600, 95% CI: 0.086-1.114, P=0.022; B=0.134, 95% CI: 0.052-0.216, P=0.001). The number of high-quality embryos, the number of available embryos, and the rate of blastocyst formation of patients in group D were significantly higher than those in group A, and the differences were statistically significant ( B=0.771, 95% CI: 0.259-1.284, P=0.003; B=0.730, 95% CI: 0.205-1.255, P=0.007; B=0.085, 95% CI: 0.003-0.167, P=0.042).After multifactorial logistic regression, there was no statistically significant difference in live birth rate between group A and groups B, C and D ( P>0.05). The cumulative live birth rate of patients in group D was significantly higher than that in group A, and the difference was statistically significant ( aOR=2.439, 95% CI: 1.169-4.974, P=0.014). Conclusion:In patients with normal ovarian reserve function, a flexible protocol of antagonists was applied to promote ovulation, and the addition of antagonists had no significant effect on the clinical outcome of the fresh embryo transfer cycle in terms of mean LH levels, but the quality of the embryos was significantly reduced when the mean LH level was <1.25 U/L, and this may consequently reduce the developmental potential of the embryos and the cumulative live birth rate.

Objective:To explore the effect of vaginal microbiota disorder on pregnancy outcomes in the first-time frozen-thawed embryo transfer (FET) patients and perinatal outcomes in single pregnancy live delivery patients.Methods:The clinical data of 2 299 cycles of FET patients in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2021 to December 2022 were collected in a retrospective cohort study. According to the types of dominant bacteria in the vaginal microbiota before transplantation, they were divided into three groups: control group (dominant bacteria were Lactobacillus, which was Gram positive bacteria, 1 849 cycles), the Gram negative bacilli group (191 cycles), and the Gram positive cocci group (259 cycles). Baseline data and pregnancy outcomes were compared among the three groups. The perinatal outcomes of select single pregnancy live birth FET patients who met the inclusion criteria were further analyzed among the three groups. The main observation indicators were live birth rate, miscarriage rate, and preterm birth rate. A multivariate logistic regression model was used to control confounding factors in the main observation indicators, and to analyze the relationship between dominant bacterial types in the vaginal microbiota and live birth rate, miscarriage rate, and preterm birth rate.Results:The difference in endometrial thickness on the day of transplantation among control group, Gram negative bacilli group, and Gram positive cocci group was statistically significant [(9.38±1.58) mm, (9.56±1.70) mm, and (9.84±1.74) mm, respectively, P<0.001]. In the endometrium preparation methods, the proportion of down-regulation+artificial cycle patients in the Gram positive cocci group was higher than that in control group, and the difference was statistically significant [13.13% (34/259) and 7.46% (138/1 849), respectively, P<0.016 7]. In the pregnancy outcomes, there was a statistically significant difference in live birth rate among control group, Gram negative bacilli group, and Gram positive cocci group [49.86% (922/1 849), 49.21% (94/191) and 41.70% (108/259), respectively, P=0.048]. The live birth rate of the Gram positive cocci group was lower than that of control group, and the difference between the two groups was statistically significant ( P<0.016 7). There were no statistically significant differences in other pregnancy outcomes and perinatal outcomes of single pregnancy live birth FET patients (all P>0.05). The multivariate logistic regression model corrected for female age, infertility years, basal follicle stimulating hormone, anti-Müllerian hormone, proportion of single embryo transfer, proportion of single blastocyst transfer, endometrial thickness on transfer day, and endometrial preparation methods, Gram positive cocci were independent risk factors for live brith after FET transplantation (a OR=0.73, 95% CI: 0.55-0.95, P=0.021). Conclusion:The dominant bacteria in the vaginal microbiota before embryo transfer are Gram positive cocci, which may be related to a decrease in live birth rate in first-time FET patients, but not significantly related to the perinatal outcomes.

Objective:To observe the effect of early elevation of luteinizing hormone (LH) with flexible gonadotropin-releasing hormone antagonist (GnRH-A) protocol on pregnancy outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) fresh embryo transfer. Methods:A retrospective cohort study was conducted to analyze patients with normal ovarian reserve function who underwent IVF/ICSI with flexible GnRH-A protocol at the Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from January 2016 to September 2021. According to the level of LH before antagonist addition, the patients were divided into two groups, group A: early elevation of LH (LH >10 U/L before the addition of antagonist, n=65), group B: the patients whose LH≤10 U/L before the addition of antagonist ( n=193), which was matched with group A using the 1∶3 propensity score matching by age, duration of infertility, anti-Müllerian hormone, body mass index and antral follicle count. The general conditions, clinical data, embryonic laboratory indicators and clinical outcomes were compared between the two groups. Results:There were no significant differences in the baseline characteristics between the two groups (all P>0.05). There were no significant differences in basic LH levels, gonadotropin (Gn) initiation dosage, total dosage and duration of Gn used, duration of Gn used when adding antagonists and estradiol (E 2) level on the trigger day between group A and group B (all P>0.05). The LH level [12.2 (11.1, 17.5) U/L], E 2 level [3 301.0 (2 708.0, 4 275.0) pmol/L] and follicle diameter [14.0 (12.6, 15.5) mm] were significantly higher in group A than in group B [3.5 (2.2, 5.2) U/L, 2 178.5 (1 208.0, 3 218.0) pmol/L, 13.0 (12.0, 14.0) mm] when adding antagonist (all P<0.001). The level of LH in group A decreased rapidly after adding antagonist, LH level in group A after antagonist application [3.4 (2.0, 5.2) U/L] and the LH level on the trigger day [3.0 (1.7, 4.7) U/L] were still higher than those in group B [2.1 (1.5, 3.3) U/L, P<0.001; 2.1 (1.4, 3.3) U /L, P=0.004], the level of progesterone on the trigger day was not significantly higher than that in group B ( P>0.05). There were no statistically significant differences in the number of oocytes retrieved, two pronuclei fertilization rate, the rate of high-quality embryo, the rate of blastocyst formation, endometrial thickness on the day of transplantation, the number of transferred embryos, the proportion of transferred blastocysts and the implantation rate between the two groups (all P>0.05). The clinical pregnancy rate, the early abortion rate, and the live birth rate were not statistically different between the two groups (all P>0.05). Conclusion:In patients with normal ovarian reserve, LH level was elevated early with antagonist flexible protocol, and decreased rapidly after the timely addition of antagonist, which did not lead to an increase of progesterone on the trigger day, and ultimately did not affect the clinical outcomes of IVF/ICSI fresh embryo transfer.

Objective:To investigate the timing of the first frozen-thawed embryo transfer (FET) on clinical and perinatal outcomes in whole embryo freezing patients, who used the medroxyprogesterone acetate (MPA) in progestin primed ovarian stimulation (PPOS).Methods:A retrospective cohort study was conducted to analyze the clinical data of patients with the first FET after ovulation induction by PPOS protocol in Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from January 2015 to November 2021. According to the time interval between the day of oocytes retrieved and the day of the first FET in the ovulation induction cycle, they were divided into two groups. Group A: transplantation was performed during the first menstrual cycle after oocyte retrieval (time interval ≥24 d and <45 d, n=80), group B: transplantation was performed at least one month apart after oocytes retrieved (time interval ≥45 d, n=1 040). After propensity score matching (PSM), the general data, clinical excretion promotion, embryo laboratory indicators, indicators related to the first FET cycle, clinical and perinatal outcomes were compared between the two groups. Results:Before PSM, the age of group A was significantly higher than that of group B [38 (35, 41) years vs. 37 (32, 40) years, P=0.020]. After PSM, there were no significant differences in general data, ovulation induction cycle data, embryo laboratory indicators, clinical pregnancy rate, live birth rate and perinatal outcomes between the two groups (all P>0.05). Conclusion:Compared with FET at least one month after oocytes retrieval, FET during the first menstrual cycle after PPOS does not affect clinical or perinatal outcomes. FET can be performed as early as possible after oocytes retrieval according to the condition of patients to shorten the time to reach their first live birth.

Objective:To observe the effect of early elevation of luteinizing hormone (LH) with flexible gonadotropin-releasing hormone antagonist (GnRH-A) protocol on pregnancy outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) fresh embryo transfer. Methods:A retrospective cohort study was conducted to analyze patients with normal ovarian reserve function who underwent IVF/ICSI with flexible GnRH-A protocol at the Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from January 2016 to September 2021. According to the level of LH before antagonist addition, the patients were divided into two groups, group A: early elevation of LH (LH >10 U/L before the addition of antagonist, n=65), group B: the patients whose LH≤10 U/L before the addition of antagonist ( n=193), which was matched with group A using the 1∶3 propensity score matching by age, duration of infertility, anti-Müllerian hormone, body mass index and antral follicle count. The general conditions, clinical data, embryonic laboratory indicators and clinical outcomes were compared between the two groups. Results:There were no significant differences in the baseline characteristics between the two groups (all P>0.05). There were no significant differences in basic LH levels, gonadotropin (Gn) initiation dosage, total dosage and duration of Gn used, duration of Gn used when adding antagonists and estradiol (E 2) level on the trigger day between group A and group B (all P>0.05). The LH level [12.2 (11.1, 17.5) U/L], E 2 level [3 301.0 (2 708.0, 4 275.0) pmol/L] and follicle diameter [14.0 (12.6, 15.5) mm] were significantly higher in group A than in group B [3.5 (2.2, 5.2) U/L, 2 178.5 (1 208.0, 3 218.0) pmol/L, 13.0 (12.0, 14.0) mm] when adding antagonist (all P<0.001). The level of LH in group A decreased rapidly after adding antagonist, LH level in group A after antagonist application [3.4 (2.0, 5.2) U/L] and the LH level on the trigger day [3.0 (1.7, 4.7) U/L] were still higher than those in group B [2.1 (1.5, 3.3) U/L, P<0.001; 2.1 (1.4, 3.3) U /L, P=0.004], the level of progesterone on the trigger day was not significantly higher than that in group B ( P>0.05). There were no statistically significant differences in the number of oocytes retrieved, two pronuclei fertilization rate, the rate of high-quality embryo, the rate of blastocyst formation, endometrial thickness on the day of transplantation, the number of transferred embryos, the proportion of transferred blastocysts and the implantation rate between the two groups (all P>0.05). The clinical pregnancy rate, the early abortion rate, and the live birth rate were not statistically different between the two groups (all P>0.05). Conclusion:In patients with normal ovarian reserve, LH level was elevated early with antagonist flexible protocol, and decreased rapidly after the timely addition of antagonist, which did not lead to an increase of progesterone on the trigger day, and ultimately did not affect the clinical outcomes of IVF/ICSI fresh embryo transfer.

Objective:To investigate the timing of the first frozen-thawed embryo transfer (FET) on clinical and perinatal outcomes in whole embryo freezing patients, who used the medroxyprogesterone acetate (MPA) in progestin primed ovarian stimulation (PPOS).Methods:A retrospective cohort study was conducted to analyze the clinical data of patients with the first FET after ovulation induction by PPOS protocol in Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from January 2015 to November 2021. According to the time interval between the day of oocytes retrieved and the day of the first FET in the ovulation induction cycle, they were divided into two groups. Group A: transplantation was performed during the first menstrual cycle after oocyte retrieval (time interval ≥24 d and <45 d, n=80), group B: transplantation was performed at least one month apart after oocytes retrieved (time interval ≥45 d, n=1 040). After propensity score matching (PSM), the general data, clinical excretion promotion, embryo laboratory indicators, indicators related to the first FET cycle, clinical and perinatal outcomes were compared between the two groups. Results:Before PSM, the age of group A was significantly higher than that of group B [38 (35, 41) years vs. 37 (32, 40) years, P=0.020]. After PSM, there were no significant differences in general data, ovulation induction cycle data, embryo laboratory indicators, clinical pregnancy rate, live birth rate and perinatal outcomes between the two groups (all P>0.05). Conclusion:Compared with FET at least one month after oocytes retrieval, FET during the first menstrual cycle after PPOS does not affect clinical or perinatal outcomes. FET can be performed as early as possible after oocytes retrieval according to the condition of patients to shorten the time to reach their first live birth.

Objective:To investigate the effect of trophoectoderm biopsy of blastocysts on serum β-human chorionic gonadotropin (β-hCG) in early pregnancy and perinatal outcome after frozen-thawed embryo transfer (FET) in the preimplantation genetic testing (PGT).Methods:It was a retrospective cohort study. Patients who underwent FET in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to December 2021 were recruited. The patients were divided into two groups according to the progestation method: 308 patients underwent trophoectoderm biopsy (PGT group) and 802 patients underwent intracytoplasmic sperm injection (ICSI group). The patients were matched at 1∶2 with propensity score matching (PSM), then there were 300 patients in PGT group and 571 patients in ICSI group. The general conditions and perinatal outcomes were compared among PGT group and ICSI group before and after PSM. Multivariate linear regression was applied to analyze the effect of trophoectoderm biopsy to serum β-hCG level by day 14 after embryo transfer.Results:Before PSM, the female age in PGT group was significantly higher than that in ICSI group [(31.2±4.1) years vs. (30.4±4.3) years, P=0.007]. The anti-Müllerian hormone levels [(4.38±3.62) μg/L vs. (4.87±3.78) μg/L, P=0.049] and endometrial thickness on the day of embryo transfer [(9.1±1.6) mm vs. (9.6±1.6) mm, P<0.001] were lower in PGT group than in ICSI group. There was no significant difference in the general data between the two groups after PSM (all P>0.05). Before and after PSM, there was no significant difference in serum β-hCG level on day 14 after embryo transfer between PGT and ICSI groups of the all patients, clinical pregnancy patients, early abortion patients and live birth patients (all P>0.05). There were no significant differences in biochemical pregnancy rate, clinical pregnancy rate, early abortion rate and live birth rate between the two groups before and after matching (all P>0.05). Multivariate linear regression analysis showed that whether or not PGT was performed had no effect on serum β-hCG levels ( P=0.494), and female body mass index and type of blastocyst transferred had an effect on β-hCG levels (all P<0.001). There were no significant differences in the incidences of hypertensive disorder complicating pregnancy, gestational diabetes, hypothyroidism during pregnancy, premature rupture of membranes, placenta previa between the two groups (all P>0.05). The cesarean section rate, premature delivery rate, low birth weight rate, macrogenesis rate, sex ratio, neonatal body mass, neonatal length and neonatal birth defects rate were not significantly different between the two groups (all P>0.05). Conclusion:Trophoectoderm biopsy of blastocysts before FET does not affect serum β-hCG level in early pregnancy, and does not increase the risk of maternal and infant adverse complications.

Objective:To investigate the effect of trophoectoderm biopsy of blastocysts on serum β-human chorionic gonadotropin (β-hCG) in early pregnancy and perinatal outcome after frozen-thawed embryo transfer (FET) in the preimplantation genetic testing (PGT).Methods:It was a retrospective cohort study. Patients who underwent FET in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2017 to December 2021 were recruited. The patients were divided into two groups according to the progestation method: 308 patients underwent trophoectoderm biopsy (PGT group) and 802 patients underwent intracytoplasmic sperm injection (ICSI group). The patients were matched at 1∶2 with propensity score matching (PSM), then there were 300 patients in PGT group and 571 patients in ICSI group. The general conditions and perinatal outcomes were compared among PGT group and ICSI group before and after PSM. Multivariate linear regression was applied to analyze the effect of trophoectoderm biopsy to serum β-hCG level by day 14 after embryo transfer.Results:Before PSM, the female age in PGT group was significantly higher than that in ICSI group [(31.2±4.1) years vs. (30.4±4.3) years, P=0.007]. The anti-Müllerian hormone levels [(4.38±3.62) μg/L vs. (4.87±3.78) μg/L, P=0.049] and endometrial thickness on the day of embryo transfer [(9.1±1.6) mm vs. (9.6±1.6) mm, P<0.001] were lower in PGT group than in ICSI group. There was no significant difference in the general data between the two groups after PSM (all P>0.05). Before and after PSM, there was no significant difference in serum β-hCG level on day 14 after embryo transfer between PGT and ICSI groups of the all patients, clinical pregnancy patients, early abortion patients and live birth patients (all P>0.05). There were no significant differences in biochemical pregnancy rate, clinical pregnancy rate, early abortion rate and live birth rate between the two groups before and after matching (all P>0.05). Multivariate linear regression analysis showed that whether or not PGT was performed had no effect on serum β-hCG levels ( P=0.494), and female body mass index and type of blastocyst transferred had an effect on β-hCG levels (all P<0.001). There were no significant differences in the incidences of hypertensive disorder complicating pregnancy, gestational diabetes, hypothyroidism during pregnancy, premature rupture of membranes, placenta previa between the two groups (all P>0.05). The cesarean section rate, premature delivery rate, low birth weight rate, macrogenesis rate, sex ratio, neonatal body mass, neonatal length and neonatal birth defects rate were not significantly different between the two groups (all P>0.05). Conclusion:Trophoectoderm biopsy of blastocysts before FET does not affect serum β-hCG level in early pregnancy, and does not increase the risk of maternal and infant adverse complications.