Embryo Transfer Strategy Of The Patients With Low Available Embryos

Background According to the World Health Organization(WHO),it is estimated that 10% to 25% couples of childbearing age suffer from infertility,and the incidence is still increasing following the loads of employment and social competition,aggravation of environmental pollution.Since the first test-tube baby in the world,Louis Brown,was born in 1978,the technique of In vitro fertilization and embryo transfer(IVF-ET)developed rapidly,and has become a routine therapeutics for infertility,and there have been more than five million babies born through IVF-ET worldwide.Since the policy that every couple could have two baby was promulgated in 2015,more infertile couples have being sought for help to get pregnancy in our country,obtaining a number of good quality embryo and optimal endometrial environment is the key for successful IVF-ET.The embryos cultured in vitro is not only a process of embryo growth,but also an embryo screening.Through extending the culture time in vitro,the embryos with development blocks and chromosomal abnormalities could be screened out,while the embryos with more developmental potential could be obtained.With the rapid development of cell culture equipment and reagent,it has become a reality to prolong embryo culture in vitro now,and the opportunity of embryo transfer time was also prolonged from day two(D2)after fertilization to D3 and D5 and D6.However,with the extending of embryo culture,the embryo consumption rate(ECR)is also increased.It was reported that the blastocyst formation rate of D3 good embryos were only 30% to 50%,moreover,there were no significant difference in cumulative pregnancy rate between blastocyst and cleavage transfer.The POR patients with fewer oocytes and available embryos have less opportunity to get blastocyst.It is worse that there might be no available embryos on D3 for the patients with low available embryos,resulting in cycle cancelled,loading a severe mental stress on both patients and physicians.This study was aimed to investigate whether transferring embryos on D2 could decrease the ECR and improve the clinical outcomes of IVF-ET for the patients with low available embryos.Part I Embryo transfer strategy of the patients with low available embryos in IVF/ICSI cycles【Objective】 To investigate the effects of D2 embryo transfer on the clinical outcomes of in vitro fertilization or intracytoplasmic sperm injection(IVF/ICSI)for the patients with low available embryo【Methods】 1.Patients: The data of 346 fresh IVF/ICSI cycles in the patients no more than 40 years old and available embryos number ≤3 from Dec.2015 to Oct.2017 were analyzed in this retrospective study.According to the embryos transferred on D2 and D3,all enrolled subjects were divided into Group D2(182 cycles)and Group D3(164 cycles).The clinical outcomes of Group D2 and Group D3,as well as D2 transfered(82 cycles)with its previous D3 transfer ed(79 cycles)in Group D2 were compared each other.The exclusion criteria(meet one of the following):(1)Advanced age(>40 years);(2)Non-fresh transfer cycles;(3)Without available embryos on D2 and D3;(4)Transferring blastocyst;(5)Patients with severe physical diseases and/or alcoholism and drug abuser;(6)Severe endometriosis,polycystic ovary syndrome;(7)Congenital uterine malformation and intrauterine adhesions.2.Statistical analysis: SPSS 16.0 software package was used to establish database for statistical analysis,and quantitative data are expressed as mean ± SD.Statistical comparisons were carried out using t-test,rank test and chi-squared test where appropriate,and P < 0.05 was considered statistically significant.【Results】 1.Comparison of Group D2 and D3: There was no statistically significant difference in patients characteristics between two groups(P >0.05),while the anti-Müllerian hormone(AMH)and antral follicle count(AFC)in Group D2 were significantly lower than those in Group D3(P < 0.05).The number of oocytes collected,the rates of MII,fertilization,cleavage and embryo consumption in Group D2 were significantly lower than those in Group D3(P < 0.05),while good embryo rate in D2 group was significantly higher than Group D3(P < 0.05).There were no significant difference in the total dosage and duration of gonadotrophins administration,endometrial thickness,transferred embryos,embryo implantation rate,clinical pregnancy rate,early abortion rate and ectopic pregnancy rate between two groups(P >0.05).2.Self-controlled comparison between D2 transfer cycles and D3 transfer cycles : The number of oocytes collected,fertilization rate,embryo consumption rate,available embryos number and cycle cancellation rate in D2 transfer cycles were significantly lower than previous D3 transfer cycles(P < 0.05),while the good embryo rate,embryo implantation rate and clinical pregnancy rate were significantly higher than previous D3 transfer cycles(P < 0.05).【Conclusion】Transferring total embryo on D2 might be a valuable alternative strategy for the patients with low available embryos.Part Ⅱ Embryo transfer strategy of the aged patients with low available embryos【Objective】 To investigate the effects of different embryo transfer strategies on the clinical outcomes of IVF/ICSI for aged women with low available embryos.【Methods】 1.Patients: The data of 184 fresh IVF/ICSI cycles in the patients more than 40 years old and available embryos number ≤3 from Dec.2015 to Oct.2017 were analyzed in this retrospective study.According to the embryos transferred on D 2 and D 3,all enrolled subjects were divided into Group D2(89 cycles)and Group D3(95 cycles).The clinical outcomes of Group D2 and Group D3,as well as D2 transfered(55 cycles)with its previous D3 transfer ed(65 cycles)in Group D2 were compared each other.The exclusion criteria(meet one of the following):(1)Advanced age(<40 years);(2)Non-fresh transfer cycle;(3)Without available embryos on D2 and D3;(4)Transferring blastocyst;(5)Patients with severe physical diseases and/or alcoholism and drug abuser;(6)Severe endometriosis,polycystic ovary syndrome;(7)Congenital uterine malformation and intrauterine adhesions.2.Statistical analysis: SPSS 16.0 software package was used to establish database for statistical analysis,and quantitative data are expressed as mean ± SD.Statistical comparisons were carried out using t-test,rank test and chi-squared test where appropriate,and P < 0.05 was considered statistically significant.【Results】 1.Comparison of Group D2 and D3: There was no statistically significant difference in patients characteristics between two groups(P>0.05).The baseline follicle-stimulating hormone(b FSH)in Group D2 were significantly higher than that in Group D3(P < 0.05),while the previous IVF/ICSI cycles,level of AMH and AFC in Group D2 were significantly lower than those in Group D3(P < 0.05).The number of oocytes collected,MII oocytes rate and embryo consumption rate in Group D2 group were significantly lower than those in Group D3(P < 0.05),while the good embryo rate in Group D2 was significantly higher than D3 group(P < 0.05).There were no significant difference in total dosage and duration of gonadotrophins administration,endometrial thickness,fertilization rate,transferred embryos,embryo implantation rate,clinical pregnancy rate and early abortion rate between two groups(P >0.05).2.Self-controlled comparison between D2 transfer cycles and D3 transfer cycles: The number of oocytes collected,fertilization rate,embryo consumption rate and cycle cancellation rate in D2 transfer cycles were significantly lower than previous D3 transfer cycles(P < 0.05),while the good embryo rate,embryo implantation rate and clinical pregnancy rate in D2 transfer cycles were significantly higher than previous D3 transfer cycles(P < 0.05).【Conclusion】 Transferring total embryos in D2 may be a valuable alternative strategy for aged women with previous implantation failure and less available embryos.