Prediction of embryo euploidy and pregnancy outcome by blastocyst morphology and development speed for women receiving single embryo transfer.

BACKGROUND: Selection of high-quality blastocysts is the most important factor determining the success of assisted reproductive technology. The objective of this study is to assess the values of blastocyst morphological quality and development speed for predicting euploidy and clinical pregnancy outcome. METHODS: A total of 155 preimplantation genetic testing cycles including 959 blastocysts and 154 euploid blastocyst transfer cycles conducted between January 2018 and December 2019 were retrospectively analysed. The associations of blastocyst morphological quality and development speed (D) with chromosomal status, clinical pregnancy rate, early miscarriage rate, and ongoing pregnancy rate were evaluated by univariate and multivariate regression. RESULTS: The euploidy rate of development speed D5 blastocysts was significantly greater than that of D6 blastocysts (61.4% vs. 38.1%, P < 0.001), and the euploid rate of morphologically high-grade blastocysts was significantly greater than that of non-high-grade blastocysts. Development speed D5 (OR = 1.6, 95% CI 1.2-2.2, P = 0.02) and high-grade morphology (OR = 2.1, 95% CI 1.5-2.9, P = 0.01) were independent predictors of euploidy. The ongoing pregnancy rate of D5 blastocysts was significantly higher than that of D6 blastocysts (62.3% vs. 43.8%, P = 0.04). Transfer of euploid blastocysts with high-grade morphology resulted in a greater ongoing pregnancy rate than transfer of non-high-grade euploid blastocysts (60.7% vs. 43.2%, P = 0.049). Alternatively, D6 development speed was an independent risk factor for early pregnancy loss after euploid blastocyst transfer. Multivariate regression analysis adjusting for confounding factors identified maternal age, blastocyst development speed, and blastocyst morphological grade as independent predictors of euploidy but not of clinical pregnancy. CONCLUSION: The recommended sequence of embryo transfer based on the present study is D5 high-grade > D6 high-grade > D5 non-high-grade > D6 non-high-grade.

Assisted reproductive technology physicians are actively exploring methods to improve the accuracy of embryo selection for successful pregnancy. We evaluated the associations of embryo morphological grade and development speed with chromosomal status and clinical outcome for couples without a history of infertility, in vitro fertilisation failure, or recurrent miscarriage receiving euploid embryo transfer. Blastocysts from females younger than 35 years, of high morphological grade, and demonstrating faster development speed were most likely to be euploid (least likely to have chromosomal abnormalities). Alternatively, patients implanted with slower developing euploid blastocysts were at higher risk of early pregnancy loss. To maximise the probability of implanting euploid embryos and minimise the risk of pregnancy loss, the selection order of embryo transferred should be based on embryo development speed followed by morphological grades.

Retrospective analysis of the endometrial preparation protocols for frozen-thawed embryo transfer cycles in women with endometriosis.

BACKGROUND: There was inconsistency in optimal endometrial preparation protocol for frozen-thawed embryo transfer (FET) in patients with endometriosis. We conducted this study to investigate the effect of different endometrial preparation protocols on the pregnancy outcomes in patients with endometriosis undergoing FET cycles, and determine the optimal number of GnRHa injections in GnRHa-HRT protocols. METHOD(S): This was a retrospective cohort analysis of women with endometriosis who underwent FET cycles at a single university-based center. This study retrospectively analyzed 2048 FET cycles in our center from 2011 to 2020. According to the endometrial preparation protocols, patients were divided into 4 groups: gonadotropin releasing hormone agonist-hormone replacement therapy(GnRHa-HRT), hormone replacement therapy(HRT), ovulation induction(OI), and natural cycle(NC). In the GnRHa-HRT group, patients were further divided into 3 groups: one injection of GnRHa, two injections of GnRHa, and three or more injections of GnRHa. The primary outcome was the clinical pregnancy rate. Propensity score matching was used to adjust for potential non-similarities among the groups. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy outcomes. RESULT(S): There were no statistical differences in pregnancy outcomes among the four endometrial preparation protocols in FET cycles with endometriosis patients, the results retained after propensity score matching(PSM). And in endometriosis patients complicated with adenomyosis, the results remained similar. In patients with GnRHa-HRT protocol, there were no differences in clinical pregnancy rate and live birth rate with different numbers of GnRHa injections, the early miscarriage rate were 18% in the two injections of GnRHa group and 6.5% in the one injection of GnRHa group(P = 0.017). Multifactorial logistic regression analysis showed that two injections of GnRHa before FET was associated with increased early miscarriage rate compared with one injection of GnRHa[adjusted OR (95% CI): 3.116(1.079-8.998),p = 0.036]. CONCLUSION(S): The four kinds of endometrial preparation protocols for FET, GnRHa-HRT, HRT, OI and NC had similar pregnancy outcomes in patients with endometriosis. In endometriosis patients complicated with adenomyosis, the results remained similar. In patients with endometriosis undergoing GnRHa-HRT protocol for FET, more injections of GnRHa had no more advantages in pregnancy outcomes, on the contrary, it might increase the early miscarriage rate.

Storage time does not influence pregnancy and neonatal outcomes for first single vitrified high-quality blastocyst transfer cycle.

RESEARCH QUESTION: Does blastocyst storage time have an impact on pregnancy and neonatal outcomes following the first single vitrified/warmed high-quality blastocyst transfer cycle for young women? DESIGN: Retrospective cohort study in a university-affiliated reproductive medical centre. RESULTS: A total of 2938 patients undergoing their first frozen embryo transfer (FET) cycle with a single high-quality blastocyst (Day 5: 3BB and above; Day 6: 4BB and above) transferred were divided into five groups: Group A with storage time ≤3 months (n = 1621), Group B with storage time of 4-6 months (n = 657), Group C with storage time of 7-12 months (n = 225), Group D with storage time of 13-24 months (n = 104), and Group E with storage time of 25-98 months (n = 331). After adjusting for confounding factors by multivariate logistic regression, there were no significant differences in live birth rate [Group A as reference; Group B: adjusted odds ratio (aOR) 0.954 (95% CI 0.791- 1.151); Group C: aOR 0.905 (95% CI 0.674-1.214); Group D: aOR 0.727 (95% CI 0.474-1.114); Group E: aOR 1.185 (955 CI 0.873-1.608)], ß-human-chorionic-gonadotropin-positive rate, clinical pregnancy rate and miscarriage rate between Group A and the other groups. Among all singletons born after FET, there were no significant differences with regards to gestational age, preterm birth, birthweight, low birthweight, high birthweight and macrosomia. CONCLUSION: Long-term cryostorage of human vitrified high-quality blastocysts does not affect pregnancy or neonatal outcomes.

[Preimplantation genetic diagnosis for carriers of thalassemia and chromosomal abnormality].

OBJECTIVE: To provide preimplantation genetic diagnosis(PGD) for two couples carrying thalassemia mutations and chromosomal abnormalities. METHODS: Couple 1 were both carriers of ß 41/42 thalassemia mutations, while the husband has carried a reciprocal translocation with a karyotype of 46,XY,inv(9)(p11;q13),t(11;22)(q25;q13). Couple 2 were both carriers of α (-SEA) thalassemia mutation. Their chromosome karyotypes were both normal, but had two spontaneous abortions. The couples had received 1 and 3 blastocysts respectively through in vitro fertilization(IVF) cycles. Following the biopsy, the cells underwent whole genome amplification, and the amplified DNA from each embryo was subjected to genetic testing and a 23-chromosome single nucleotide polymorphism(SNP) microarray assay. RESULTS: The embryo of couple 1 was diagnosed as carrier of ß 41/42 thalassemia with euploid chromosomes. The embryo was transferred and resulted in intrauterine pregnancy. Similarly, an embryo of couple 2 was verified as carrier of α (-SEA) thalassemia with euploid chromosomes. CONCLUSION: PGD for aneuploidy coupled with testing for single gene disorders via trophectoderm biopsy and whole genome amplification is feasible. The approach can attain diagnosis with minimal damage with sound clinical outcome.