Pregnancy Outcomes for Day 5 Versus Day 6 Single Frozen-thawed Blastocyst Transfer with Different Qualities of Embryos: A Large Matched-cohort Study

Objective This study aimed to determine whether the day of blastocyst expansion affects pregnancy outcomes in frozen-thawed blastocyst transfer(FBT)cycles.Methods A retrospective match-cohort study was conducted.Patients who underwent blastocyst transfer in frozen-thawed cycles at day 5 or 6 were matched for potential confounding factors.A total of 2207 matched pairs of FBT cycles were included from January 2016 to December 2019 in our Reproductive Medicine Center.Results The clinical pregnancy rate(CPR)and live birth rate(LBR)were significantly increased in day 5 blastocyst transfers when compared to day 6 blastocyst transfers,in terms of the same embryo quality.For FBT cycles with good-quality embryo,the CPR at day 5 and 6 was 61.30%and 57.56%,respectively(P=0.045),and the LBR was 44.79%and 36.16%,respectively(P<0.001).For FBT cycles with poor-quality embryo,the CPR at day 5 and 6 was 48.61%and 40.89%,respectively(P=0.006),and the LBR was 31.71%and 25.74%,respectively(P=0.019).The CPR for FBT cycles with good-quality embryo was statistically higher at day 6 than that at day 5 with poor-quality embryo transferred(57.56%vs.48.61%,P=0.001).Maternal age,anti-Müllerian hormone(AMH),endometrial thickness,embryo quality,and the day of blastocyst expansion were independently correlated with the CPR and LBR.The FBT cycles at day 5 had significantly higher CPR(adjusted odds ratio[OR]=1.246,95%confidence intervals[CI]:1.097–1.415,P=0.001)and LBR(adjusted OR=1.435,95%CI:1.258–1.637,P<0.001)than those at day 6.Conclusion The embryo quality is the primary indicator for FBT cycles.Day 5 blastocysts should be preferred when the quality of embryo at day 5 is the same as that at day 6.

Influence of Different Gonadotropin-releasing Hormone Agonist Administration Methods on Pregnancy Outcomes of Patients Undergoing In-vitro Fertilization-embryo Transfer

This study aimed to investigate the effect of different gonadotropin-releasing hormone agonist (GnRH-a) administration methods on pregnancy outcomes of patients undergoing in-vitro fertilization-embryo transfer (IVF-ET). Clinical data of 5217 patients who underwent IVF-ET were retrospectively analyzed. Patients were divided into the long-acting GnRH-a group (n=1330) and the short-acting GnRH-a group (w=3887) based on their various treatment plans. The clinical and laboratory embryo data and clinical pregnancy outcomes were compared between the two groups. The results showed that there were no significant differences in the age, infertility, primary/secondary infertility rate, IVF rate, body mass index (BMI), antral follicle counting (AFC), folliclestimulating hormone (FSH) level, and the number of transplanted embryos between the two groups (P>0.05). There were no significant differences in the oocyte numbers, M II rate, fertilization rate, cleavage rate and blastocyst formation rate (P>0.05) between the two groups. The gonadotropin (Gn) using days, Gn dose and endometrial thickness were significantly greater in the long-acting GnRH-a group than those in the short-acting GnRH-a group (P<0.01). Additionally, the estradiol (E2) levels, blastocyst freezing rate, embryo utilization rate, transplant cancellation rate and abortion rate were significantly lower in the long-acting GnRH-a group than those in the shortacting GnRH-a group (P<0.01). The clinical pregnancy rate and embryo implantation rate were significantly higher in the long-acting GnRH-a group than in the short-acting GnRH-a group (P<O.Ol). It was concluded that use of long-acting GnRH-a can effectively reduce the transplant cancellation rate and improve the clinical pregnancy rate of the fresh cycle.

Developmental Potential and Clinical Value of Embryos with Abnormal Cleavage Rate

To investigate the developmental potential and clinical value of embryos with abnormal cleavage rate,a retrospective analysis was performed on 66 635 2-prokaryotic(2PN)and 1-pronuclear(1PN)embryos.The embryos were given conventionally in vitro fertilization(IVF)treatment and continuously cultured on the day 3(D3)at the Reproductive Medicine Center,Tongji Medical College,Huazhong University of Science and Technology from January 2016 to December 2017.The embryos were separated into the day-2(D2)undivided group with 106 cases,the arrested development group with 3482 cases,the blastomere reduction group with 541 cases,and the control group with 62 506 cases,respectively.The blastocyst utilization rates of these three abnormal groups were 2.83%,10.86%and 6.84%,respectively,which were significantly different from that in control group(39.46%).Furthermore,2 cases of anabiosis and 1 case of live birth were found in D2 undivided group.In arrested development group,there were 55 cases of anabiosis,11 cases of clinical pregnancy in single-embryo transplantation(including 6 cases of live birth),and 25 cases of clinical pregnancy in combination with one normal embryo transplantation(including 23 cases of live births and 15 cases of dizygotic twins under B-ultrasound).There were 13 case of anabiosis in blastomere reduction group:there was 1 case of single embryo transplantation and clinical pregnancy was obtained;there were also 6 cases of clinical pregnancy in combination with one single normal embryo transplantation(including 5 cases of live births and 2 cases of di2ygotic twins under B-ultrasound).In conclusion,embryos with abnormal cleavage rate still have the potential to continue to develop,and have certain blastocyst utilization rate and live birth.

High-quality Cleavage Embryo versus Low-quality Blastocyst in Frozen-thawed Cycles:Comparison of Clinical Outcomes

This study compared the clinical outcomes of the frozen-thawed cycles of high-quality cleavage embryos with low-quality blastocysts to provide a reference for the choice of frozen-thawed embryo transfer schemes and to improve clinical pregnancy rates.A retrospective analysis was performed on the clinical data of patients undergoing frozen-thawed embryo transfer at the Reproductive Medicine Center of Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from 2016 to 2017.In total,845 cases were divided into a high-quality cleavage embryo group(group A)and a low-quality blastocyst group(group B).Each group was further divided into subgroups based on the number of transplants.Group A was categorized into two subgroups comprising of 94 cases in subgroup Al(1 high-quality 8-cell group)and 201 cases in subgroup A2(2 high-quality 8-cell group).Group B was divided into four subgroups consisting of 73 cases in subgroup B I(D53BC group),65 cases in subgroup B2(D54BC group),110 cases in subgroup B3(D63BC group),and 282 cases in subgroup B4(D64BC group).The pregnancy outcomes and neonatal outcomes between the groups were compared.The clinical pregnancy rates(56.72%and 60.00%)and live birth rates(47.76%and 46.15%)in subgroups A2 and B2 showed no significant differences,but these rates were significantly higher in subgroups A2 and B2 than in the rest subgroups(P<0.05).The multiple birth rate(26.32%)in the subgroup A2 was significantly higher than that in the rest subgroups(P<0.05).There were no statistically significant differences in the abortion rates among all groups(P>0.05).In terms of neonatal outcomes,there were no statistically significant differences in the proportion of premature births,sex ratios,and birth defects among the low-weight and gigantic infants(P>0.05).Transplanting two high-quality cleavage embryos during the frozen-thawed embryo transfer cycles could significantly increase clinical pregnancy rates and live birth rates,but at the same time,it also increased the risks of multiple births and complications to mothers and infants.The D54BC subgroup had the most significant advantages among all groups(P<0.05).The rest low-quality blastocysts had clinical outcomes similar to the single high-quality cleavage embryo group.

Rescue ICSI: Choose the Optimal Rescue Window before Oocyte Aging

Objective To evaluate the application value of rescue ICSI in fertilization failure after conventional IVF and choose the best rescue window before oocyte aging according to the results of rescue ICSI performed in different time. Methods The data of 93 IVF cycles were analyzed retrospectively. Rescue ICSI was performed in these cycles after conventional IVF failure. Because of the different rescue time, these cycles were divided into two groups： early rescue group （group A, 77 cycles, rescue ICSI performed 4-8 h after conventional IVF） and late rescue group （group B, 16 cycles, rescue ICSI performed 20-22 h after conventional IVF）. Results There were no statistically significant differences in age of female, duration of infertility, number of oocytes retrieved every cycle. The normal fertilization rate, pregnancy rate and implantation rate were decreased in group B compared with those in group A （P〈0.05）. In group A, the normal fertilization rate of rescue ICSI performed 4-6 h after conventional IVF （group A1） was increased compared with that of rescue ICSI performed 6-8 h （including 6 h） after conventional IVF （group A2）（66.5% vs 55.9%）（P〈0.05）; while the abnormal fertilization rate in group A1 was decreased compared with group A2 （9.0% vs 14.4%）（P〈0.05）. Clinical pregnancy rate was slight higher in group A1 than in group A2, though this failed to be significantly different. Conclusion Rescue ICSI is effective if fertilization was failure after conventional IVF, the most important thing is to choose the reasonable rescue window before oocyte aging when ICSI is performed.