Objective: To compare the effectiveness before and after the adjustment of schistosomiasis control strategies in Nanjing City, so as to provide the evidence for improving schistosomiasis control interventions. Methods: The prevalence of Schistosomasis japonicum infections in humans, livestock, Oncomelania hupensis and sentinel mice was collected in Nanjing City from 1993 to 2018, and the prevalence of S. japonicum infections in humans, livestock, sentinel mice and O. hupensis, and the areas of snail habitats, areas of infected snail habitats and snail control areas were compared before (1993-2004) and after (2005-2018) the adjustment of schistosomiasis control strategies to evaluate the effectiveness. Results: The prevalence of S. japonicum infections in humans, livestock, O. hupensis and sentinel mice was 0.77% and 0.02% (χ2=6 430.634, P<0.001), 0.46% and 0.01% (χ2=344.401, P<0.001), 0.19% and 0.11% (χ2=239.685, P<0.001), and 34.35% and 1.56% (χ2=1 856.286, P<0.001) in Nanjing City before and after the adjustment of schistosomiasis control strategies, respectively. The median areas (interquartile range) of snail habitats, infected snail habitats and snail control were 4 175.37 (1 301.65) and 2 366.44 (885.27) hm2 (Z=-3.755, P<0.001), 870.49 (1 001.75) and 0 (158.89) hm2 (Z=-3.654, P<0.001) and 1 383.23 (793.57) and 5 031.94 (629.11) hm2 (Z=-4.320, P<0.001) in Nanjing City before and after the adjustment of schistosomiasis control strategies, respectively. Conclusions After the adjustment of schistosomiasis control strategies, remarkable effects on schistosomiasis control has achieved in Nanjing City, where the transmission of schistosomiasis was interrupted. Nevertheless, the strategy requires to be continued and improved to move towards elimination of schistosomiasis in Nanjing City.

Objective:To evaluate the clinical effects of antagonist protocol and progestin-primed ovarian stimulation (PPOS) protocol in patients with low prognosis.Methods:A total of 1560 controlled ovarian stimulation cycles of 1419 patients consistent with POSEIDON low prognosis with antagonist protocol or PPOS protocol in the treatment of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) from January 2016 to December 2018 in the Reproductive Medicine Center of Henan Provincial People's Hospital were collected in a retrospective cohort study. The essential characteristic, clinical characteristics, laboratory index and clinical outcomes of patients in the antagonist protocol group and the PPOS protocol group were compared. Multivariate logistic regression analysis was used to compare cumulative live rate per ovulation cycle after adjusting for confounders of the two controlled ovarian stimulation protocols. Results:The comparison of the general conditions of the patients with the two controlled ovarian stimulation protocols showed that anti-Müllerian hormone (AMH) [1.45(0.68, 3.28) μg/L] and antral follicle count (AFC) [7.00(4.00,11.00) μg/L] in the antagonist protocol group were significantly higher than those in the PPOS protocol group [1.10(0.55, 2.71) μg/L, P=0.002; 6.00(3.00, 9.00) μg/L, P=0.010], and basal follicle-stimulating hormone (FSH) [7.65(6.26, 9.99) U/L] was significantly lower than that in the PPOS protocol group [7.88(6.29, 10.58) U/L, P=0.007]. The results of laboratory and clinical outcomes showed that the estrogen level [726.20(415.30,1 095.00) ng/L] on human chorionic hormone (hCG) injection day in the antagonist protocol group was significantly lower than that in the PPOS protocol group [738.00(412.55, 1 187.75) ng/L, P=0.028], and the endometrial thickness [(9.31±2.67) mm] on hCG injection day, the cumulative pregnancy rate [49.35% (379/768)] and the cumulative live birth rate per ovulation cycle [38.04% (291/765)] were significantly higher than those in the PPOS protocol group [(6.81±2.26) mm, P<0.001; 37.62% (298/792), P<0.001; 26.08% (206/790), P<0.001]. After adjusting for confounder factors, the cumulative pregnancy rate ( OR=1.58, 95% CI=1.24-2.01, P<0.001) and the cumulative live birth rate ( OR=1.68, 95% CI=1.30-2.17, P<0.001) per ovulation cycle in the antagonist protocol group were higher than those in the PPOS protocol group in patients with POSEIDON low prognosis. The results of stratified analysis showed that the cumulative pregnancy rate and the cumulative live birth rate per ovulation cycle of antagonist protocol group per ovulation cycle was higher than that of PPOS protocol group. The cumulative pregnancy rate and the cumulative live birth rate per ovulation cycle in different age ( P<0.001, P<0.001), insemination method ( P<0.001, P<0.001), AMH ( P<0.001, P<0.001) and POSEIDON group 1 ( P=0.001, P<0.001) and POSEIDON group 3 ( P=0.008, P=0.024) were statistically different. Conclusion:In patients with low prognosis of POSEIDON, the antagonist protocol improved the cumulative live birth rate per ovulation cycle compared with the PPOS protocol, especially for patients in POSEIDON group 1 and POSEIDON group 3.

Objective:To evaluate the clinical effects of antagonist protocol and progestin-primed ovarian stimulation (PPOS) protocol in patients with low prognosis.Methods:A total of 1560 controlled ovarian stimulation cycles of 1419 patients consistent with POSEIDON low prognosis with antagonist protocol or PPOS protocol in the treatment of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) from January 2016 to December 2018 in the Reproductive Medicine Center of Henan Provincial People's Hospital were collected in a retrospective cohort study. The essential characteristic, clinical characteristics, laboratory index and clinical outcomes of patients in the antagonist protocol group and the PPOS protocol group were compared. Multivariate logistic regression analysis was used to compare cumulative live rate per ovulation cycle after adjusting for confounders of the two controlled ovarian stimulation protocols. Results:The comparison of the general conditions of the patients with the two controlled ovarian stimulation protocols showed that anti-Müllerian hormone (AMH) [1.45(0.68, 3.28) μg/L] and antral follicle count (AFC) [7.00(4.00,11.00) μg/L] in the antagonist protocol group were significantly higher than those in the PPOS protocol group [1.10(0.55, 2.71) μg/L, P=0.002; 6.00(3.00, 9.00) μg/L, P=0.010], and basal follicle-stimulating hormone (FSH) [7.65(6.26, 9.99) U/L] was significantly lower than that in the PPOS protocol group [7.88(6.29, 10.58) U/L, P=0.007]. The results of laboratory and clinical outcomes showed that the estrogen level [726.20(415.30,1 095.00) ng/L] on human chorionic hormone (hCG) injection day in the antagonist protocol group was significantly lower than that in the PPOS protocol group [738.00(412.55, 1 187.75) ng/L, P=0.028], and the endometrial thickness [(9.31±2.67) mm] on hCG injection day, the cumulative pregnancy rate [49.35% (379/768)] and the cumulative live birth rate per ovulation cycle [38.04% (291/765)] were significantly higher than those in the PPOS protocol group [(6.81±2.26) mm, P<0.001; 37.62% (298/792), P<0.001; 26.08% (206/790), P<0.001]. After adjusting for confounder factors, the cumulative pregnancy rate ( OR=1.58, 95% CI=1.24-2.01, P<0.001) and the cumulative live birth rate ( OR=1.68, 95% CI=1.30-2.17, P<0.001) per ovulation cycle in the antagonist protocol group were higher than those in the PPOS protocol group in patients with POSEIDON low prognosis. The results of stratified analysis showed that the cumulative pregnancy rate and the cumulative live birth rate per ovulation cycle of antagonist protocol group per ovulation cycle was higher than that of PPOS protocol group. The cumulative pregnancy rate and the cumulative live birth rate per ovulation cycle in different age ( P<0.001, P<0.001), insemination method ( P<0.001, P<0.001), AMH ( P<0.001, P<0.001) and POSEIDON group 1 ( P=0.001, P<0.001) and POSEIDON group 3 ( P=0.008, P=0.024) were statistically different. Conclusion:In patients with low prognosis of POSEIDON, the antagonist protocol improved the cumulative live birth rate per ovulation cycle compared with the PPOS protocol, especially for patients in POSEIDON group 1 and POSEIDON group 3.

Objective:To investigate the effect of altering trigger timing on clinical outcomes of low prognosis patients with gonadotropin-releasing hormone (GnRH) antagonist.Methods:A retrospective cohort study was conducted on 1613 cycles of low prognosis patients based on POSEIDON criteria undergoing in vitro fertilization-embryo transfer (IVF-ET) with GnRH antagonist protocol between January 2017 to June 2019 in Reproductive Medicine Center, Henan Provincial People's Hospital. Patients were divided into 3 groups depending on different trigger timing criteria (conventional trigger group, n=961; advanced trigger group, n=359; delayed trigger group, n=293). Univariate analysis and multivariate logistic regression analysis were used to analyze the effect of trigger timing on clinical outcomes such as cumulative pregnancy rate (CPR) and cumulative live birth rate (CLBR) among different groups. Results:The clinical pregnancy rate of fresh cycle in advanced trigger group, conventional trigger group, delayed trigger group were 35.77% (44/123), 39.16% (150/383), 34.01% (50/147), respectively. CPR and CLBR ranked from low to high in order of advanced trigger group, conventional trigger group and delayed trigger group [CPR: 33.18% (72/217) vs. 42.23% (276/652) vs. 45.27% (91/201), P=0.024; CLBR: 22.97% (48/209) vs. 31.96% (201/629) vs. 35.90% (70/159), P=0.012]. The result of multivariate logistics regression analysis showed that there were no significant differences on clinical pregnancy rate, CPR and CLBR among three groups [delayed trigger group: the clinical pregnancy rate in fresh cycle OR(95% CI)=0.69(0.44-1.09), P=0.114; CPR OR(95% CI)=0.77 (0.51-1.16), P=0.214; CLBR OR(95% CI)=0.83(0.54-1.29), P=0.418; advanced trigger group: the clinical pregnancy rate in fresh cycle OR(95% CI)=0.98(0.60-1.60), P=0.934; CPR OR(95% CI)=0.87(0.58-1.30), P=0.513; CLBR OR(95% CI)=0.86(0.54-1.35), P=0.515]. Conclusion:Conventional trigger could obtain the ideal clinical outcomes in low prognosis patients based on P

Objective:To investigate the effect of endometrial thickness (EMT) on the clinical outcome of hormone replacement frozen-thawed embryo transfer (HRT-FET) cycle in different body mass index (BMI) groups, and to analyze the threshold and optimal EMT and EMT interval corresponding to the ideal clinical pregnancy rate.Methods:A retrospective cohort study was conducted on 10 239 HRT-FET cycles in the Reproductive Medicine Center of Henan Provincial People's Hospital from January 2013 to December 2017, and they were divided into low weight group (BMI<18.5 kg/m 2), normal weight group (BMI=18.5-24.9 kg/m 2), overweight group (BMI=25.0-29.9 kg/m 2) and obese group (BMI≥30.0 kg/m 2). Four subgroups were divided according to EMT, respectively EMT<8.0 mm, 8.0 mm≤EMT<10.0 mm, 10.0 mm≤EMT<12.0 mm, EMT≥12.0 mm. The clinical characteristics and outcome indicators of different EMT subgroups in different BMI groups were compared. To achieve the ideal clinical pregnancy rate, multiple regression analysis, curve fitting and threshold effect analysis were used to find the best EMT and thickness interval. Results:1) After adjusting for confounding factors, multiple regression analysis showed that, there were no significant differences in clinical pregnancy rate and live birth rate among subgroups with the increase of EMT (all groups P>0.05). The clinical pregnancy rate and the live birth rate increased with the increase of EMT between subgroups of normal body weight group and super-recombinant subgroups (all P<0.001 for normal body weight subgroups, P=0.123, P=0.009, P=0.016 and all P<0.001 for super-recombinant subgroups). In the obesity group, with the increase of EMT, the clinical pregnancy rate did not increase significantly except EMT≥12.0 mm subgroup ( P=0.449, P=0.279, P=0.021), while the live birth rate increased significantly ( P=0.014, P=0.005, P<0.001). 2) Curve fitting showed that in the population of low weight and obese, influence of EMT on clinical pregnancy rate was a straight line, in the population of normal weight and overweight, influence of EMT on clinical pregnancy rate was a curve, as EMT increased the clinical pregnancy rate raised and then decreased, the impact on the live birth rate appeared similar. 3) According to the curve fitting, the threshold effect analysis of the normal weight group showed that the endometrial inflection point of EMT on the clinical pregnancy rate and the live birth rate was 10.0 mm. When EMT was lower than 10.0 mm, the clinical pregnancy rate and the live birth rate increased by 20% and 19% for every 1.0 mm increase in endometrial thickness ( OR=1.20, 95% CI=1.13-1.26; OR=1.13,95% CI=1.13-1.26). In overweight group, the inflection point of EMT on the clinical pregnancy rate and the live birth rate was also 10.0 mm. When EMT was lower than 10.0 mm, the clinical pregnancy rate and the live birth rate increased by 24% and 26% for every 1.0 mm increase in EMT ( OR=1.24, 95% CI=1.13-1.26; OR=1.26, 95% CI=1.14-1.40). When EMT exceeded 10.0 mm, the clinical pregnancy rate and the live birth rate did not increase significantly with the increase of EMT. Conclusion:In HRT-FET cycle, the endometrial thickness has an effect on the clinical pregnancy rate and the live birth rate in the normal weight group and the overweight group. The clinical pregnancy rate and the live birth rate were the best when the EMT was between 10.0-13.5/10.0-12.7 mm and 10.0-14.0/10.0-12.5 mm, respectively. Whether the endometrium was too thin or too thick would affect the clinical pregnancy outcome. The influence of EMT on clinical pregnancy rate and live birth rate was linear between the low weight group and the obese group, but further study is needed.

Objective:To explore the clinical strategies to improve the clinical outcomes of patients with thin endometrium.Methods:A retrospective cohort study was conducted to analyze 1924 frozen-thawed embryo transfer (FET) cycles of 2452 patients with thin endometrium at the Reproductive Medicine Center of Henan Provincial People's Hospital from January 2013 to December 2019. According to the type of embryos transferred, they were divided into the embryo group at cleavage stage (cleavage embryo group) and embryo group at blastocyst stage (blastocyst group). Univariate analysis, multivariate regression analysis, curve fitting and threshold effect analysis were used to compare the clinical outcomes of the cycles transferring cleavage stage embryo and blastocyst.Results:The percentage of cycles with two embryos transferred [87.17% (1298/1489)], the rate of ectopic pregnancy [3.35% (16/477)] and the rate of multiple births [23.32% (73/313)] in cleavage embryo transfer cycle were higher than those of blastocyst transfer cycle [40.71% (392/963), P<0.001; 0.76% (4/524), P=0.003; 16.27% (55/338), P=0.024]. The clinical pregnancy rate [54.41% (524/963)] and the live birth rate [35.10% (338/963)] in blastocyst transfer cycle were significantly higher than those of cleavage embryo transfer cycle [32.03% (477/1489), P<0.001; 21.02% (313/1489), P<0.001]. After adjusting for confounders, the clinical pregnancy rate ( OR=3.42, 95% CI=2.71-4.31, P<0.001) and the live birth rate ( OR=2.35, 95% CI=1.84-3.00, P<0.001) of blastocyst transfer cycle were higher than those of cleavage stage embryo transfer cycle. The results of stratified analysis showed that the clinical pregnancy rate (<6 mm: OR=2.94, 95% CI=1.32-6.51, P=0.008; 6-7 mm: OR=3.41; 95% CI=2.13-5.45, P<0.001; >7 mm: OR=3.56, 95% CI=2.67-4.74, P<0.001) and the live birth rate (<6 mm: OR=2.50, 95% CI=1.01-6.22, P=0.049; 6-7 mm: OR=2.56, 95% CI=1.56-4.21, P<0.001; >7 mm: OR=2.30, 95% CI=1.71-3.10, P<0.001) of blastocyst transfer cycle in different endometrial thickness stratifications were higher than those of cleavage stage embryo transfer cycle. The results of stratified curve fitting analysis showed that with increasing endometrial thickness among patients with thin endometrium, the clinical pregnancy rate and the live birth rate of both cleavage stage embryo cycle and blastocyst transfer cycle increased, and in all of the different endometrial thickness stratifications, the clinical pregnancy rate and the live birth rate in blastocyst transfer cycle were higher than those of cleavage embryo transfer cycle. Compared with the blastocyst transfer cycle, the slope of curve fitting between endometrial thickness and clinical pregnancy rate was larger in cleavage embryo transfer cycle. Conclusion:The clinical pregnancy rate and the live birth rate of the blastocyst transfer cycle in FET were higher than those of cleavage stage embryo transfer cycle. The increasement of endometrial thickness on the first day of progesterone administration can improve the clinical pregnancy rate and the live birth rate in patients with thin endometrium.

Objective:To investigate the effect of altering trigger timing on clinical outcomes of low prognosis patients with gonadotropin-releasing hormone (GnRH) antagonist.Methods:A retrospective cohort study was conducted on 1613 cycles of low prognosis patients based on POSEIDON criteria undergoing in vitro fertilization-embryo transfer (IVF-ET) with GnRH antagonist protocol between January 2017 to June 2019 in Reproductive Medicine Center, Henan Provincial People's Hospital. Patients were divided into 3 groups depending on different trigger timing criteria (conventional trigger group, n=961; advanced trigger group, n=359; delayed trigger group, n=293). Univariate analysis and multivariate logistic regression analysis were used to analyze the effect of trigger timing on clinical outcomes such as cumulative pregnancy rate (CPR) and cumulative live birth rate (CLBR) among different groups. Results:The clinical pregnancy rate of fresh cycle in advanced trigger group, conventional trigger group, delayed trigger group were 35.77% (44/123), 39.16% (150/383), 34.01% (50/147), respectively. CPR and CLBR ranked from low to high in order of advanced trigger group, conventional trigger group and delayed trigger group [CPR: 33.18% (72/217) vs. 42.23% (276/652) vs. 45.27% (91/201), P=0.024; CLBR: 22.97% (48/209) vs. 31.96% (201/629) vs. 35.90% (70/159), P=0.012]. The result of multivariate logistics regression analysis showed that there were no significant differences on clinical pregnancy rate, CPR and CLBR among three groups [delayed trigger group: the clinical pregnancy rate in fresh cycle OR(95% CI)=0.69(0.44-1.09), P=0.114; CPR OR(95% CI)=0.77 (0.51-1.16), P=0.214; CLBR OR(95% CI)=0.83(0.54-1.29), P=0.418; advanced trigger group: the clinical pregnancy rate in fresh cycle OR(95% CI)=0.98(0.60-1.60), P=0.934; CPR OR(95% CI)=0.87(0.58-1.30), P=0.513; CLBR OR(95% CI)=0.86(0.54-1.35), P=0.515]. Conclusion:Conventional trigger could obtain the ideal clinical outcomes in low prognosis patients based on P

Objective:To investigate the effect of endometrial thickness (EMT) on the clinical outcome of hormone replacement frozen-thawed embryo transfer (HRT-FET) cycle in different body mass index (BMI) groups, and to analyze the threshold and optimal EMT and EMT interval corresponding to the ideal clinical pregnancy rate.Methods:A retrospective cohort study was conducted on 10 239 HRT-FET cycles in the Reproductive Medicine Center of Henan Provincial People's Hospital from January 2013 to December 2017, and they were divided into low weight group (BMI<18.5 kg/m 2), normal weight group (BMI=18.5-24.9 kg/m 2), overweight group (BMI=25.0-29.9 kg/m 2) and obese group (BMI≥30.0 kg/m 2). Four subgroups were divided according to EMT, respectively EMT<8.0 mm, 8.0 mm≤EMT<10.0 mm, 10.0 mm≤EMT<12.0 mm, EMT≥12.0 mm. The clinical characteristics and outcome indicators of different EMT subgroups in different BMI groups were compared. To achieve the ideal clinical pregnancy rate, multiple regression analysis, curve fitting and threshold effect analysis were used to find the best EMT and thickness interval. Results:1) After adjusting for confounding factors, multiple regression analysis showed that, there were no significant differences in clinical pregnancy rate and live birth rate among subgroups with the increase of EMT (all groups P>0.05). The clinical pregnancy rate and the live birth rate increased with the increase of EMT between subgroups of normal body weight group and super-recombinant subgroups (all P<0.001 for normal body weight subgroups, P=0.123, P=0.009, P=0.016 and all P<0.001 for super-recombinant subgroups). In the obesity group, with the increase of EMT, the clinical pregnancy rate did not increase significantly except EMT≥12.0 mm subgroup ( P=0.449, P=0.279, P=0.021), while the live birth rate increased significantly ( P=0.014, P=0.005, P<0.001). 2) Curve fitting showed that in the population of low weight and obese, influence of EMT on clinical pregnancy rate was a straight line, in the population of normal weight and overweight, influence of EMT on clinical pregnancy rate was a curve, as EMT increased the clinical pregnancy rate raised and then decreased, the impact on the live birth rate appeared similar. 3) According to the curve fitting, the threshold effect analysis of the normal weight group showed that the endometrial inflection point of EMT on the clinical pregnancy rate and the live birth rate was 10.0 mm. When EMT was lower than 10.0 mm, the clinical pregnancy rate and the live birth rate increased by 20% and 19% for every 1.0 mm increase in endometrial thickness ( OR=1.20, 95% CI=1.13-1.26; OR=1.13,95% CI=1.13-1.26). In overweight group, the inflection point of EMT on the clinical pregnancy rate and the live birth rate was also 10.0 mm. When EMT was lower than 10.0 mm, the clinical pregnancy rate and the live birth rate increased by 24% and 26% for every 1.0 mm increase in EMT ( OR=1.24, 95% CI=1.13-1.26; OR=1.26, 95% CI=1.14-1.40). When EMT exceeded 10.0 mm, the clinical pregnancy rate and the live birth rate did not increase significantly with the increase of EMT. Conclusion:In HRT-FET cycle, the endometrial thickness has an effect on the clinical pregnancy rate and the live birth rate in the normal weight group and the overweight group. The clinical pregnancy rate and the live birth rate were the best when the EMT was between 10.0-13.5/10.0-12.7 mm and 10.0-14.0/10.0-12.5 mm, respectively. Whether the endometrium was too thin or too thick would affect the clinical pregnancy outcome. The influence of EMT on clinical pregnancy rate and live birth rate was linear between the low weight group and the obese group, but further study is needed.

Objective:To explore the clinical strategies to improve the clinical outcomes of patients with thin endometrium.Methods:A retrospective cohort study was conducted to analyze 1924 frozen-thawed embryo transfer (FET) cycles of 2452 patients with thin endometrium at the Reproductive Medicine Center of Henan Provincial People's Hospital from January 2013 to December 2019. According to the type of embryos transferred, they were divided into the embryo group at cleavage stage (cleavage embryo group) and embryo group at blastocyst stage (blastocyst group). Univariate analysis, multivariate regression analysis, curve fitting and threshold effect analysis were used to compare the clinical outcomes of the cycles transferring cleavage stage embryo and blastocyst.Results:The percentage of cycles with two embryos transferred [87.17% (1298/1489)], the rate of ectopic pregnancy [3.35% (16/477)] and the rate of multiple births [23.32% (73/313)] in cleavage embryo transfer cycle were higher than those of blastocyst transfer cycle [40.71% (392/963), P<0.001; 0.76% (4/524), P=0.003; 16.27% (55/338), P=0.024]. The clinical pregnancy rate [54.41% (524/963)] and the live birth rate [35.10% (338/963)] in blastocyst transfer cycle were significantly higher than those of cleavage embryo transfer cycle [32.03% (477/1489), P<0.001; 21.02% (313/1489), P<0.001]. After adjusting for confounders, the clinical pregnancy rate ( OR=3.42, 95% CI=2.71-4.31, P<0.001) and the live birth rate ( OR=2.35, 95% CI=1.84-3.00, P<0.001) of blastocyst transfer cycle were higher than those of cleavage stage embryo transfer cycle. The results of stratified analysis showed that the clinical pregnancy rate (<6 mm: OR=2.94, 95% CI=1.32-6.51, P=0.008; 6-7 mm: OR=3.41; 95% CI=2.13-5.45, P<0.001; >7 mm: OR=3.56, 95% CI=2.67-4.74, P<0.001) and the live birth rate (<6 mm: OR=2.50, 95% CI=1.01-6.22, P=0.049; 6-7 mm: OR=2.56, 95% CI=1.56-4.21, P<0.001; >7 mm: OR=2.30, 95% CI=1.71-3.10, P<0.001) of blastocyst transfer cycle in different endometrial thickness stratifications were higher than those of cleavage stage embryo transfer cycle. The results of stratified curve fitting analysis showed that with increasing endometrial thickness among patients with thin endometrium, the clinical pregnancy rate and the live birth rate of both cleavage stage embryo cycle and blastocyst transfer cycle increased, and in all of the different endometrial thickness stratifications, the clinical pregnancy rate and the live birth rate in blastocyst transfer cycle were higher than those of cleavage embryo transfer cycle. Compared with the blastocyst transfer cycle, the slope of curve fitting between endometrial thickness and clinical pregnancy rate was larger in cleavage embryo transfer cycle. Conclusion:The clinical pregnancy rate and the live birth rate of the blastocyst transfer cycle in FET were higher than those of cleavage stage embryo transfer cycle. The increasement of endometrial thickness on the first day of progesterone administration can improve the clinical pregnancy rate and the live birth rate in patients with thin endometrium.

Objective:To analyze the effect of age and number of oocytes obtained on the cumulative live birth rate per oocytes retrieval cycle in in vitro fertilization-embryo transfer (IVF-ET), and to explore the ideal number of oocytes obtained in IVF-ET. Methods:Totally 10 002 controlled ovarian stimulation cycles from March 2016 to December 2018 in the Reproductive Medicine Center of Henan Provincial People's Hospital were studied retrospectively. The general condition, clinical and laboratory indicators and clinical outcomes of the different oocytes obtained numbers were compared, and multivariate logistic regression analysis after adjusting confounding factors was used to investigate the effect of the number of oocytes obtained on the clinical outcomes, curve fitting and threshold effect analysis were performed to analyze the influence of the number of oocytes obtained on the cumulative live birth rate per oocytes retrieval cycle.Results:A total of 10 002 oocytes retrieval cycles were collected and a total of 5904 cycles of live births were obtained, with a total cumulative live birth rate of 59.03% (5904/10 002). The endometrial thickness on human chorionic gonadotropin (hCG) injection day was (10.31±3.09) mm, the median number of oocytes obtained was 8.00(5.00,12.00), the median number of mature oocytes was 7.00(4.00,11.00), and the median number of normal fertilization was 5.00(2.00,8.00), the median number of embryos available on day 3 (D3) was 4.00(2.00,7.00). The results of logistics regression analysis adjusted for confounding factors showed that the cumulative live birth rate per egg retrieval cycle in patients with 1-3 oocytes obtained ( OR=0.11, 95% CI=0.12-0.18), 4-6 oocytes obtained ( OR=0.32, 95% CI=0.33-0.44), 7-9 oocytes obtained ( OR=0.62, 95% CI=0.54-0.71) was significantly lower than that of patients with 10-15 oocytes obtained ( P<0.000 1), while it was significantly higher in patients with 16-20 oocytes ( OR=1.54, 95% CI=1.24-1.93) and ≥21 oocytes ( OR=2.49, 95% CI=1.76-3.52) than that in patients with 10-15 oocytes obtained ( P<0.000 1). The curve fitting and threshold effect analysis results showed that when the number of oocytes obtained was less than 19, the cumulative live birth rate increased significantly with the number of oocytes obtained, 16% increase in cumulative live birth rate for each additional oocytes ( OR=1.16, 95% CI=1.15-1.18, P<0.000 1). When the number of oocytes was ≥19, the cumulative live birth rate was stable and no longer increased ( OR=1.00, 95% CI=0.96-1.05, P=0.840 3). Conclusion:There is a curve relationship between the number of oocytes obtained and the cumulative live birth in IVF-ET cycle. When the number of oocytes obtained was <19, the cumulative live birth rate increased significantly with the increase of the number of oocytes obtained, but when the number of oocytes obtained was ≥19, the cumulative live birth rate did not increase significantly with it, but rather tend to be stable.