Since the birth of the first "test-tube baby" in Chinese mainland in 1988, assisted reproductive technology (ART) in China has matured significantly. The number of ART cycles has surpassed one million, and the number of assisted reproductive institutions and practitioners has attained a significant scale, contributing to the establishment of a fertility-friendly society. However, due to the complexity of the ART process, the diversity of personnel backgrounds, and the profound impact of any error that may occur, there is an urgent need to establish an efficient and effective safety management model for error prevention. This paper aims to outline the key processes and steps involved in the implementation of ART, explore control measures for these critical processes, and delve into error prevention strategies for gamete and embryo laboratories through the creation and utilization of a "gamete safety checklist".

Objective:To investigate the outcomes of natural cycle (NC) and modified natural cycle (MNC) assisted reproductive technology (ART) in patients with diminished ovarian reserve (DOR), and to provide a scientific basis for individualized treatment strategies for DOR patients.Methods:A retrospective cohort analysis was performed on the clinical data of DOR patients who underwent ART at the Center for Reproductive Medicine of the Department of Obstetrics and Gynecology, Peking University Third Hospital from January 1, 2015 to December 31, 2023. Patients were divided into the NC group ( n=801) and the MNC group ( n=385) based on their treatment protocol. The primary outcomes were cycle cancellation rate and oocyte retrieval rate. Secondary outcomes included clinical pregnancy rate and live birth rate per fresh embryo transfer cycle and frozen-thawed embryo transfer cycle, cumulative pregnancy rate and cumulative live birth rate per started cycle and per transfer cycle, as well as laboratory parameters such as the number of retrieved oocytes, the number of two pronuclei (2PN) fertilized oocytes, the number of transferable embryos, and transferable embryo formation rate. Further, multivariate logistic regression was used to analyze the impact of the treatment protocol on pregnancy and live birth outcomes. Results:There were no statistically significant differences between the NC and MNC groups in terms of general characteristics such as age, body mass index, and baseline hormone levels (all P>0.05). The cycle cancellation rate was significantly higher in the NC group [19.10% (153/801)] than in the MNC group [10.65% (41/385), P<0.001], and the oocyte retrieval rate was significantly lower in the NC group [66.31% (431/650)] than in the MNC group [74.86% (259/346), P=0.005]. The number of retrieved oocytes [1 (0,1)], the number of 2PN fertilized oocytes [1 (0,1)], and the number of transferable embryos [0 (0, 1)] were also significantly lower in the NC group than in the MNC group [1 (1, 2), P<0.001; 1 (1, 1), P<0.001; 0 (0, 1), P<0.001]. However, there were no statistically significant differences in 2PN fertilization rate and transferable embryo formation rate between the NC and MNC groups (all P>0.05). In both fresh embryo transfer cycles and frozen-thawed embryo transfer cycles, there were no statistically significant differences in clinical pregnancy rate and live birth rate between the NC and MNC groups (all P>0.05). The cumulative pregnancy rate per started cycle and transfer cycle, the cumulative live birth rate per started cycle and per transfer cycle were also not significantly different between the NC and MNC groups (all P>0.05). Multivariate logistic analysis showed no significant association between NC and clinical pregnancy or live birth compared with MNC. Conclusion:While MNC to some extent reduced the cycle cancellation rate and improved oocyte retrieval rates compared with NC, it did not ultimately improve pregnancy outcomes in DOR patients.

Since the birth of the first "test-tube baby" in Chinese mainland in 1988, assisted reproductive technology (ART) in China has matured significantly. The number of ART cycles has surpassed one million, and the number of assisted reproductive institutions and practitioners has attained a significant scale, contributing to the establishment of a fertility-friendly society. However, due to the complexity of the ART process, the diversity of personnel backgrounds, and the profound impact of any error that may occur, there is an urgent need to establish an efficient and effective safety management model for error prevention. This paper aims to outline the key processes and steps involved in the implementation of ART, explore control measures for these critical processes, and delve into error prevention strategies for gamete and embryo laboratories through the creation and utilization of a "gamete safety checklist".

Objective:To investigate the outcomes of natural cycle (NC) and modified natural cycle (MNC) assisted reproductive technology (ART) in patients with diminished ovarian reserve (DOR), and to provide a scientific basis for individualized treatment strategies for DOR patients.Methods:A retrospective cohort analysis was performed on the clinical data of DOR patients who underwent ART at the Center for Reproductive Medicine of the Department of Obstetrics and Gynecology, Peking University Third Hospital from January 1, 2015 to December 31, 2023. Patients were divided into the NC group ( n=801) and the MNC group ( n=385) based on their treatment protocol. The primary outcomes were cycle cancellation rate and oocyte retrieval rate. Secondary outcomes included clinical pregnancy rate and live birth rate per fresh embryo transfer cycle and frozen-thawed embryo transfer cycle, cumulative pregnancy rate and cumulative live birth rate per started cycle and per transfer cycle, as well as laboratory parameters such as the number of retrieved oocytes, the number of two pronuclei (2PN) fertilized oocytes, the number of transferable embryos, and transferable embryo formation rate. Further, multivariate logistic regression was used to analyze the impact of the treatment protocol on pregnancy and live birth outcomes. Results:There were no statistically significant differences between the NC and MNC groups in terms of general characteristics such as age, body mass index, and baseline hormone levels (all P>0.05). The cycle cancellation rate was significantly higher in the NC group [19.10% (153/801)] than in the MNC group [10.65% (41/385), P<0.001], and the oocyte retrieval rate was significantly lower in the NC group [66.31% (431/650)] than in the MNC group [74.86% (259/346), P=0.005]. The number of retrieved oocytes [1 (0,1)], the number of 2PN fertilized oocytes [1 (0,1)], and the number of transferable embryos [0 (0, 1)] were also significantly lower in the NC group than in the MNC group [1 (1, 2), P<0.001; 1 (1, 1), P<0.001; 0 (0, 1), P<0.001]. However, there were no statistically significant differences in 2PN fertilization rate and transferable embryo formation rate between the NC and MNC groups (all P>0.05). In both fresh embryo transfer cycles and frozen-thawed embryo transfer cycles, there were no statistically significant differences in clinical pregnancy rate and live birth rate between the NC and MNC groups (all P>0.05). The cumulative pregnancy rate per started cycle and transfer cycle, the cumulative live birth rate per started cycle and per transfer cycle were also not significantly different between the NC and MNC groups (all P>0.05). Multivariate logistic analysis showed no significant association between NC and clinical pregnancy or live birth compared with MNC. Conclusion:While MNC to some extent reduced the cycle cancellation rate and improved oocyte retrieval rates compared with NC, it did not ultimately improve pregnancy outcomes in DOR patients.

This article summarizes the current status of the application of ablation in thyroid tumors with reference to relevant guidelines and expert consensus.The application of ablation in treating benign thyroid tumors has gradually gained maturity in recent years,but the application in malignant thyroid tumors is controversial.Currently,some clinical practices are constantly trying to broaden the application of ablation in treating malignant thyroid tumors.Ablation,which is mainly applied to benign thyroid tumors,has good prognosis and high patient satisfaction.Since this technique cannot avoid the potential recurrence risk of malignant thyroid tumors or eradicate local or distant occult metastases,the indications for the use of ablation in malignant thyroid tumors should be strictly controlled.

Objective:To compare the clinical outcome of whole frozen-thawed embryo transfer in patients with high ovarian response using gonadotropin-releasing hormone agonist (GnRH-a) single trigger or combined with low-dose human chorionic gonadotropin (hCG) dual trigger in the gonadotropin-releasing hormone antagonist (GnRH-A) protocol.Methods:Retrospective cohort study was conducted in Center for Reproductive Medicine, Department of Obstetrics and Gynecology of Peking University Third Hospital between January 2018 to December 2020, and the patients with high ovarian response undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) were divided into GnRH-a single trigger group (group A, n=251) and GnRH-a combined with low-dose hCG dual trigger group (group B, n=741) according to the trigger protocol. The clinical outcome was compared between the two groups. Results:There were no significant differences in clinical characteristics between group A and group B. Estrogen level on the day of trigger, number of embryos formed, number of two pronuclei (2PN) embryos formed, number of high-quality embryos formed and rate of embryo formation in group A were significantly higher than those in group B [(22 905.84±9 513.28) pmol/L vs. (17 200.82±6 811.64) pmol/L, P<0.001; 18.84±9.50 vs. 17.34±8.04, P=0.025; 16.06±8.24 vs. 14.87±7.07, P=0.042; 11.25±6.92 vs. 10.25±5.97, P=0.027; 68.6% (4 730/6 899) vs. 66.5% (12 852/19 326), P=0.002]. However, there were no significant differences in number of oocytes retrieved, mature oocyte rate and high-quality embryo rate between group A and group B (all P>0.05). There were also no significant differences in hCG positive rate, clinical pregnancy rate, abortion rate, ectopic pregnancy rate, persistent pregnancy rate and live birth rate per frozen-thawed embryo transfer between the two groups (all P>0.05). There were no significant differences in cumulative persistent pregnancy rate, cumulative live birth rate, proportion of low birth weight infants and birth defects per ovarian stimulation cycle between the two groups (all P>0.05). The incidence of early-onset severe ovarian hyperstimulation syndrome (OHSS) in group A was lower than that in group B, but there was no significant difference [0% vs. 1.5% (11/741), P=0.075]. Conclusion:The pregnancy outcome of whole frozen-thawed embryo transfer in patients with high ovarian response using GnRH-a single trigger was comparable to dual trigger combined with low-dose hCG in the GnRH-A protocol, and the risk of early onset severe OHSS was low. Therefore, in patients with high ovarian response in IVF/ICSI cycle using GnRH-A protocol, the use of GnRH-a single trigger followed by whole frozen-thawed embryo transfer could be considered as an optimal choice to minimize the risk of early onset OHSS without loss of pregnancy outcome.

Objective:To compare the clinical outcome of whole frozen-thawed embryo transfer in patients with high ovarian response using gonadotropin-releasing hormone agonist (GnRH-a) single trigger or combined with low-dose human chorionic gonadotropin (hCG) dual trigger in the gonadotropin-releasing hormone antagonist (GnRH-A) protocol.Methods:Retrospective cohort study was conducted in Center for Reproductive Medicine, Department of Obstetrics and Gynecology of Peking University Third Hospital between January 2018 to December 2020, and the patients with high ovarian response undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) were divided into GnRH-a single trigger group (group A, n=251) and GnRH-a combined with low-dose hCG dual trigger group (group B, n=741) according to the trigger protocol. The clinical outcome was compared between the two groups. Results:There were no significant differences in clinical characteristics between group A and group B. Estrogen level on the day of trigger, number of embryos formed, number of two pronuclei (2PN) embryos formed, number of high-quality embryos formed and rate of embryo formation in group A were significantly higher than those in group B [(22 905.84±9 513.28) pmol/L vs. (17 200.82±6 811.64) pmol/L, P<0.001; 18.84±9.50 vs. 17.34±8.04, P=0.025; 16.06±8.24 vs. 14.87±7.07, P=0.042; 11.25±6.92 vs. 10.25±5.97, P=0.027; 68.6% (4 730/6 899) vs. 66.5% (12 852/19 326), P=0.002]. However, there were no significant differences in number of oocytes retrieved, mature oocyte rate and high-quality embryo rate between group A and group B (all P>0.05). There were also no significant differences in hCG positive rate, clinical pregnancy rate, abortion rate, ectopic pregnancy rate, persistent pregnancy rate and live birth rate per frozen-thawed embryo transfer between the two groups (all P>0.05). There were no significant differences in cumulative persistent pregnancy rate, cumulative live birth rate, proportion of low birth weight infants and birth defects per ovarian stimulation cycle between the two groups (all P>0.05). The incidence of early-onset severe ovarian hyperstimulation syndrome (OHSS) in group A was lower than that in group B, but there was no significant difference [0% vs. 1.5% (11/741), P=0.075]. Conclusion:The pregnancy outcome of whole frozen-thawed embryo transfer in patients with high ovarian response using GnRH-a single trigger was comparable to dual trigger combined with low-dose hCG in the GnRH-A protocol, and the risk of early onset severe OHSS was low. Therefore, in patients with high ovarian response in IVF/ICSI cycle using GnRH-A protocol, the use of GnRH-a single trigger followed by whole frozen-thawed embryo transfer could be considered as an optimal choice to minimize the risk of early onset OHSS without loss of pregnancy outcome.

Objective:To investigate the incidence rate and development trend of birth defects in offspring after assisted reproductive technology (ART) in Beijing from 2010 to 2019.Methods:The institutions that carry out ART in Beijing were retrospectively investigated. The follow-up outcomes and the incidence of birth defects in a total of 389 978 ART treatment cycles were collected from 8 ART institutions between January 1, 2010 to December 31, 2019.Results:There were 1 367 ART pregnancies with birth defects, and the overall incidence rate was 120.87/10 000. The most common anomalies were malformations of circulatory system. The annual increase in birth defects was slightly higher during the pregnancy loss cycles (108.36%) than during the delivery cycles (103.77%). There was no significant difference in the prevalence of birth defects between artificial insemination (123.15?) and in vitro fertilization technology (105.23? , P=0.097). Conclusion:In recent 10 years, the incidence rate of birth defects in offspring conceived by ART at 8 reproductive centers in Beijing showed an increasing trend. The implementation of the tertiary prevention strategy of birth defects should be further strengthened to reduce the number of newborns with birth defects.

Objective:To investigate the incidence rate and development trend of birth defects in offspring after assisted reproductive technology (ART) in Beijing from 2010 to 2019.Methods:The institutions that carry out ART in Beijing were retrospectively investigated. The follow-up outcomes and the incidence of birth defects in a total of 389 978 ART treatment cycles were collected from 8 ART institutions between January 1, 2010 to December 31, 2019.Results:There were 1 367 ART pregnancies with birth defects, and the overall incidence rate was 120.87/10 000. The most common anomalies were malformations of circulatory system. The annual increase in birth defects was slightly higher during the pregnancy loss cycles (108.36%) than during the delivery cycles (103.77%). There was no significant difference in the prevalence of birth defects between artificial insemination (123.15?) and in vitro fertilization technology (105.23? , P=0.097). Conclusion:In recent 10 years, the incidence rate of birth defects in offspring conceived by ART at 8 reproductive centers in Beijing showed an increasing trend. The implementation of the tertiary prevention strategy of birth defects should be further strengthened to reduce the number of newborns with birth defects.

Objective:To perform a comparative study of obstetric outcomes in fresh cycles and different endometrial preparation protocols in frozen-thawed embryo transfer (FET) cycles, in order to guide the follow-up clinical consulting service and applications.Methods:This retrospective cohort study was conducted in a cohort of 22 395 consecutive cases with live birth following successful in vitro fertilization and embryo transfer (IVF-ET)/FET performed at the Center for Reproductive Medicine, Department of Obstetrics and Gynecology of Peking University Third Hospital from January 2014 to June 2017. According to the method of embryo transfer cycles, they were divided into fresh cycle group, natural cycle (NC)-FET cycle group and hormone replacement therapy (HRT)-FET cycle group. The primary outcome indicators of the study were the maternal and fetal outcomes in obstetrics, and the secondary outcome indicators were the basic data such as reproductive-related clinical data and laboratory-related indicators in each group. Logistic regression was used to analyze the influence of cycles on the obstetrical outcomes. Results:Among the 22 395 cycles, there were 12 118 cycles in fresh group, 6648 cycles in NC-FET group, and 3629 cycles in HRT-FET group. Among the basic characteristics: 1) There was a statistical difference in infertility duration among the three groups ( P=0.007), and differences were also found in female age, female body mass index (BMI), male age, the proportion of infertile type, and mean endometrial thickness on human chorionic gonadotropin (hCG)/conversion day among the three groups (all P<0.001); the mean endometrial thickness among the women with the fresh cycles [(11.13±1.63) mm] was the thickest, followed by the NC-FET cycles [(10.61±1.74) mm] and the lowest in the HRT-FET cycles [(9.77±1.58) mm]. 2) The proportion of blastocysts transferred increased in the FET cycles [NC-FET cycles 54.8% (3646/6648), HRT-FET cycles 52.4% (1901/3629)] compared with fresh cycles [3.8% (461/12 118), P<0.001]. 3) The incidence of monozygotic twins after blastocyst transfer increased ( P<0.001). Maternal-fetal outcomes: 1) The difference was observed in the live birth rate among the three groups ( P>0.001). 2) There was a statistical difference in the gestational age of delivery among the three groups [fresh cycles (38.39±2.08) weeks, NC-FET cycles (38.69±1.87) weeks, HRT-FET cycles (38.40±2.31) weeks, P<0.001], the full-term pregnancy induction rate (greater than 40 weeks) [19.8% (1315/6648), 19.0% (690/3629)], the newborn weight [(3 168.05±607.90) g, (3 124.70±683.53) g] and the macrosomia rate [7.8% (521/6648), 8.5% (309/3629)] were higher in the NC-FET and HRT-FET cycles than those in fresh cycles [16.6% (2017/12 118), (3 007.61±627.60) g, 6.6% (804/12 118), all P<0.001]. 3) In HRT-FET cycles, the premature birth rate [16.9% (615/3629)], the cesarean section rate [75.7% (2748/3629)], and the low birth weight rate [12.1% (438/3629)] were significantly higher than those in NC-FET cycles [12.6% (838/6648), 69.4% (4611/6648), 9.6% (637/6648), all P<0.001]. 4) The incidence of gestational hypertension, the incidence of gestational diabetes and the incidence of premature rupture of membranes in HRT-FET cycles [5.0% (182/3629), 6.7% (244/3629), 3.4% (124/3629)] were significantly different from those in NC cycles [1.6% (198/12 118), 2.4% (198/12 118), 2.9% (351/12 118)] and NC-FET cycles [2.0% (134/6648), 6.2% (410/6648), 2.1% (140/6648), P<0.001]. 5) The incidence of placental abnormalities/postpartum hemorrhage also increased significantly in HRT-FET cycles [1.0% (37/3629)] compared with NC-FET cycles [0.6% (41/6648), P=0.042]. Conclusion:The application of FET in assisted reproductive technology is safe and becoming widespread. Fetal complications are less than the fresh cycles, but maternal obstetric complications increase during HRT-FET cycles. Therefore, in different protocols of FET, when NC-FET is available, it is recommended as the first choice.