Comparison of the clinical outcomes between fresh blastocyst and vitrified-thawed blastocyst transfer

Objective

To compare the clinical outcomes between fresh and vitrified-thawed day 5 blastocyst transfers.

Design

Retrospective case control study.

Setting

Tertiary referral center.

Patient(s)

Patients 38 years of age or less who underwent IVF/ICSI cycles with fresh or frozen-thawed blastocysts transferred from June 1, 2009 to November 30, 2011

Intervention(s)

Vitrification and thawing of day 5 blastocysts using the Cryotop method. (Kitazato BioPharma Co., Ltd., Fuji city, Shizuoka, Japan)

Main outcome measure(s)

Clinical pregnancy rate, implantation rate, ongoing pregnancy rate, and multiple pregnancy rates.

Results

Of the 118 cycles in the fresh transfer group, 234 blastocysts were transferred. The clinical pregnancy rate was 66.1 % and implantation rate was 50.9 %. The ongoing pregnancy rate was 56.8 % and the rates for singleton and twin pregnancies were 53.7 % and 44.8 %. Of the 59 cycles in the vitrified-thawed group, 111 blastocysts were transferred. The clinical pregnancy rate was 59.3 % and implantation rate was 43.2 %. The ongoing pregnancy rate was 47.5 % and the rates for singleton and twin pregnancies were 60.7 % and 39.3 %. The clinical pregnancy rate, implantation rate and ongoing pregnancy rate did not differ significantly between the two groups.

Conclusions

The implantation rates were not significantly different between the fresh and the vitrified-thawed groups. Thus, single embryo transfer may be considered in fresh cycles to decrease multiple pregnancy rates. The surplus embryos should be vitrified for the frozen embryo transfer to improve the cumulative pregnancy rate.     

Mitochondrial DNA content is associated with ploidy status,maternal age,and oocyte maturation methods in mouse blastocysts

Purpose

It was reported that mitochondrial DNA (mtDNA) was significantly increased in aneuploid human embryos compared to euploid embryos and was also associated with maternal age. In this study, we further established the mouse model of mtDNA quantitation in reproductive samples based on whole-genome amplification (WGA) and next-generation sequencing (NGS).

Methods

WGA followed by NGS-based mtDNA quantitation was first performed on 6 single- and 100-cell samples from a tumor-derived mouse cell line, which was exposed to ethidium bromide to reduce mtDNA content. The relative mtDNA content was normalized to nuclear DNA. This method was then applied to mouse reproductive samples, including 40 pairs of oocytes and polar bodies from 8 CD-1 female mice of advanced reproductive age and 171 blastocysts derived via in vitro maturation (IVM) or in vivo maturation (IVO) from young (6–9 weeks) and reproductively aged (13.5 months) female CF-1 mice.

Results

Exposure to ethidium bromide for 3 and 6 days decreased mtDNA levels in both the single- and 100-cell samples as expected. Results demonstrated that the first polar body contained an average of 0.9% of mtDNA relative to oocytes. Compared to the cells in blastocysts, oocytes contained about 180 times as much mtDNA per cell. mtDNA levels were compared among blastocysts from reproductively young and old female mice that had either been produced by IVM or IVO. Cells in blastocysts from younger mice contained significantly lower amounts of mtDNA compared to aged mice (P < 0.0001). Cells in blastocysts produced via IVO had higher mtDNA content than IVM-derived blastocysts (P = 0.0001). Cells in aneuploid blastocysts were found to have significantly higher (1.74-fold) levels of mtDNA compared to euploid blastocysts (P = 0.0006).

Conclusion

A reliable method for assessing mtDNA content in mouse gametes and embryos was established. Relative mtDNA levels were elevated in aneuploid embryos relative to euploid embryos, were higher in blastocysts from reproductively old mice relative to young mice, and were lower in embryos derived from IVM compared to IVO.

     

Possible selection of viable human blastocysts after vitrification by monitoring morphological changes

Purpose

Morphological assessment of human blastocysts has been effective for selecting embryos with high potential. However, they often show repeated shrinkage and expansion toward their hatching. Here we assessed whether capturing morphological changes over time of vitrified–warmed blastocysts could lead to a better selection of viable embryos from shrunken blastocysts.

Methods

The implantation rates of vitrified–warmed blastocysts that were shrunken or expanded (developing) at the time of loading for transfer were compared among 2,729 cycles that were subjected to single blastocyst transfer. Vitrified (107) and fresh blastocysts (17) were donated for the experimental study. To assess the relationship between morphology (expanded vs. shrunken) and the mitochondrial respiration of blastocysts, the oxygen consumption rate (OCR) was analyzed for 55 specimens using an uncoupler of oxidative phosphorylation. The remaining 69 blastocysts were used for recording morphological changes every 15 min for 48 h after warming.

Results

Because there were no surplus embryos, 7 % of the vitrified–warmed blastocysts were shrunken and transferred. The shrunken embryos had sufficient implantation ability (40 %). The OCR of the shrunken embryos was significantly lower than that of their expanded counterparts. Upon exposure to the uncoupler, the OCR of some shrunken embryos increased to levels similar to the expanded specimens. Time-lapse images revealed some shrunken embryos which formed blastocoel by 5 h following warming exhibited developmental competence to the hatched stage.

Conclusions

Data of the present study suggest a group of shrunken blastocysts contains many viable and clinically available embryos and time-lapse observation of vitrified–warmed blastocysts is a potential method to distinguish viable embryos from shrunken blastocysts.     

Time-lapse observations to analyze the effects of assisted hatching

Purpose

Assisted hatching (AH) is an artificial disruption of the zona pellucida with the aim of facilitating embryo implantation. We used time-lapse observations of mouse embryos to examine the effect of AH in mouse blastocysts.

Methods

AH techniques were performed with acid Tyrode’s solution. We compared the rates of blastocyst formation and blastocyst attachment to Ishikawa cells between the control (n = 28) and the AH group (n = 24). To analyze the effects of AH, 8-cell mice embryos were cultured under time-lapse observations (every 15 min). The time required for hatching, the hatching rates, the frequency of contraction, and the contraction rates in the blastocysts were analyzed.

Results

There were no significant differences between the two groups in hatching rate or attachment rate. The times required for hatching were 286 ± 22 min in the AH group and 990 ± 437 min in the control group (P = 0.018). The contraction frequencies in blastocysts were 3.5 ± 0.7 times in the AH group and 7.5 ± 2.5 times in the control group (P = 0.020).

Conclusions

From the time-lapse observations we found that the time required for hatching and the frequency of contraction in blastocysts were both reduced by AH, although blastocyst formation and attachment were not affected.     

Vitrification of human blastocysts previously cryopreserved by slow controlled-rate freezing at the cleavage stage

Purpose

The objective of this study was to evaluate the efficiency of vitrified blastocysts derived from frozen-thawed cleavage stage embryos in terms of morphological survival and re-expansion status of the blastocoelic cavity.

Results

After warming 162 blastocysts derived from fresh embryos (= control group) and 90 blastocysts from frozen-thawed cleavage stage embryos (= study group) and after 2–3 h of in vitro culture the percentage of blastocysts with morphological survival was not different between the two groups. After 24 h of in vitro culture, the percentage of fully expanded, hatching or hatched blastocysts was not different between both groups.

Conclusion(s)

The results show that blastocysts derived from frozen-thawed cleavage stage embryos can be cryopreserved successfully a second time by vitrification method. Re-cryopreservation by vitrification still needs to be approached with some caution because little data on long term safety of multiple freezing is available.     

Vitrification of blastocysts derived from fair to poor quality cleavage stage embryos can produce high pregnancy rates after warming

Purpose

This study investigates whether certain embryos considered unsuitable for cryopreservation on day 3 might nevertheless have the potential to develop into worthwhile blastocysts that could be vitrified in the same cycle.

Methods

Retrospective study: between 2010 and 2011, embryo transfers and cryopreservation took place mainly on day 3 in our centre. Supernumerary embryos of intermediate to poor quality were reassessed on days 5/6 and any good quality blastocysts were vitrified.

Results

Out of 914 cleavage stage (day 3) embryos left in culture, 16 % were vitrified on days 5/6. Fifty blastocyst warming cycles resulted in a 76 % survival rate, 44 % clinical pregnancy rate and 39 % implantation rate. During the same time period, 213 warming cycles of good quality cleavage stage embryos rendered survival rates, clinical pregnancy and implantation rates of 97 %, 23 % and 16 % respectively.

Conclusions

Supernumerary average quality day 3 embryos should be given a second chance to be selected for cryopreservation. If blastocysts are obtained and survive vitrification, there is a good chance of implantation thus reducing embryo waste.     

Difference in mitochondrial gene expression in granulosa cells between recombinant FSH and hMG cycles under in vitro fertilization and transfer

Purpose

Examination of the mitochondrial mRNA expression in granulosa cells from an unspecified population of infertile patients to evaluate whether recombinant follicle stimulating hormone (recFSH) is more effective in producing higher quality embryo rates compared with human menopausal gonadotropin (hMG).

Method

Thirty-nine patients who underwent the in vitro fertilization and embryo transfer program were retrospectively examined. Patients were administered recFSH (n = 18) or hMG (n = 20) in a long protocol where GnRH agonist was used. Granulosa cells were obtained during oocyte retrieval and examined for mitochondria mRNA expression ratio against GAPDH. Expressions of mitochondria mRNA were evaluated by real-time PCR analysis.

Results

The high-quality embryo rate in the hMG cycle was higher than in the recFSH cycle, and the total dose of hMG showed a positive correlation with the expression level of mitochondrial genes in granulosa cells. Moreover, mitochondria mRNA expression was higher in the hMG cycle than in the recFSH cycle.

Conclusions

Compared with recFSH, hMG induces a higher mitochondrial gene expression ratio in granulosa cells at the time of oocyte retrieval and, therefore, may lead to higher quality embryo rates.     

Effect of red light on the development and quality of mammalian embryos

Purpose

To assess irradiance and total energy dose from different microscopes during the in-vitro embryonic developmental cycle in mouse and pig and to evaluate its effect on embryonic development and quality in pig.

Method

Spectral scalar irradiance (380–1050 nm) was measured by a fiber-optic microsensor in the focal plane of a dissection microscope, an inverted microscope and a time-lapse incubation system. Furthermore, the effect of three different red light levels was tested in the time-lapse system on mouse zygotes for 5 days, and on porcine zona-intact and zona-free parthenogenetically activated (PA) embryos for 6 days.

Results

The time-lapse system used red light centered at 625 nm and with a lower irradiance level as compared to the white light irradiance levels on the dissection and inverted microscopes, which included more energetic radiation <550 nm. Even after 1000 times higher total energy dose of red light exposure in the time-lapse system, no significant difference was found neither in blastocyst development of mouse zygotes nor in blastocyst rates and total cell number of blastocysts of porcine PA embryos.

Conclusions

Our results indicate that red light (625 nm, 0.34 W/m²) used in the time-lapse incubation system does not decrease the development and quality of blastocysts in both mouse zygotes and porcine PA embryos (both zona-intact and zona-free).     

Effects of low molecular weight heparins and unfractionated heparin on viability of human umbilical vein endothelial cells

Aim

The aim of this study was to investigate the effects of bemiparin, nadroparin, enoxaparin, and heparin on viability of human umbilical vein endothelial cells (HUVEC).

Methods

Cultivation of HUVEC was performed in an incubator having 5 % CO₂ at 37 °C and with predefined supplemented medium, until cell monolayers attained confluence which occurred after 7 days. The assays were performed in the exponential growth phase of the cells. The cell viability was assessed using the cleavage of tetrazolium salts added to the culture medium. Heparin sodium, enoxaparin sodium, bemiparin sodium, and nadroparin calcium with concentrations of 100, 10, and 1 IU/100 μL were used for the proliferation assay in which cells were incubated for 24, 48, and 72 h with these drugs. The experiments were conducted in four replicates.

Results

Among the study drugs with maximal concentration used in the experiments (100 IU/100 μL), heparin was found to be associated with the lowest viability score in 24 and 48 h, while bemiparin showed the lowest at 72 h. Bemiparin 100 IU/100 μL was significantly associated with lower viability score than that of bemiparin 10 IU/100 μL and bemiparin 1 IU/100 μL at every time interval. Among gradual concentrations of enoxaparin, however, concentration of 1 IU/100 μL was associated with the lowest viability scores at every time point. Heparin 1 IU/100 μL, nadroparin 100 IU/100 μL, and enoxaparin 100 IU/100 μL groups had the highest viability score after 72 h of incubation.

Conclusion(s)

Among low molecular weight heparins (LMWHs), 100 IU/100 μL concentration of bemiparin was associated with a more pronounced effect on reducing viability of HUVEC after 72 h of incubation, while nadroparin 100 IU/100 μL and enoxaparin 100 IU/100 μL showed the least effects. LMWHs differ both from each other and heparin with respect to their effects on cellular viability of HUVEC in dose- and time-dependent manner.     

Analysis of compaction initiation in human embryos by using time-lapse cinematography

Purpose

To analyze the initiation of compaction in human embryos in vitro by using time-lapse cinematography (TLC), with the goal of determining the precise timing of compaction and clarifying the morphological changes underlying the compaction process.

Methods

One hundred and fifteen embryos donated by couples with no further need for embryo-transfer were used in this study. Donated embryos were thawed and processed, and then their morphological behavior during the initiation of compaction was dynamically observed via time-lapse cinematography (TLC) for 5 days.

Results

Although the initiation of compaction occurred throughout the period from the 4-cell to 16-cell stage, 99 (86.1 %) embryos initiated compaction at the 8-cell stage or later, with initiation at the 8-cell stage being most frequent (22.6 %). Of these 99 embryos, 49.5 % developed into good-quality blastocysts. In contrast, of the 16 (13.9 %) embryos that initiated compaction prior to the 8-cell stage, only 18.8 % developed into good-quality blastocysts. Embryos that initiated compaction before the 8-cell stage showed significantly higher numbers of multinucleated blastomeres, due to asynchronism in nuclear division at the third mitotic division resulting from cytokinetic failure.

Conclusions

The initiation of compaction primarily occurs at the third mitotic division or later in human embryos. Embryos that initiate compaction before the 8-cell stage are usually associated with aberrant embryonic development (i.e., cytokinetic failure accompanied by karyokinesis).     

Cytogenetic analysis of human embryos and embryonic stem cells derived from monopronuclear zygotes

Purpose

By comparing the chromosomal constitution among the arrested cleavage-stage embryos, blastocysts and human embryonic stem cells (hESCs) which are all derived from monopronuclear (1PN) zygotes, it is aimed to determine whether chromosomally normal embryos can be reliably selected by blastocyst culture.

Methods

After 1PN zygotes are sequentially cultured for 5 days, the blastocysts and arrested cleavage-stage embryos were analyzed by fluorescence in situ hybridization (FISH) with probes for chromosomes 18, X and Y; G-banding analysis was adopted to analyze the karyotype of 1PN hESCs.

Results

The diploid rate of blastocysts was 74.6%, which was significantly (P?<?0.001) higher than that of arrested cleavage-stage embryos (31.6%), and the diploid rate of hESCs was 97.0%, which was significantly (P < 0.01) higher than that of blastocysts; the haploid embryos were excluded by blastocyst culture; nevertheless, there still existed such chromosomal abnormalities as mosaic and monosomic in blastocysts and trisomy in hESCs.

Conclusions

Blastocyst culture is an effective method to select against chromosomal abnormalities, especially the haploids in 1PN embryos; however, development to the blastocyst stage is not a reliable marker for mosaicism or aneuploidy.     

Comparison of differences in development potentials between frozen-thawed D5 and D6 blastocysts and their relationship with pregnancy outcomes

Purpose

Whether there are differences in the pregnancy outcomes of blastocysts cryopreserved during different developmental stages remains under debate because the results among studies are inconsistent. We analyzed blastocyst quality and pregnancy outcomes by considering blastocyst euploidy and investigated the differences in the development potential between blastocysts of different developmental stages (frozen-thawed day 5 [D5] and day 6 [D6] cycles) and their relationship with clinical pregnancy outcomes.

Methods

In total, 1374 D5 and 255 D6 frozen-thawed blastocyst transfer cycles were retrospectively analyzed. Additionally, the chromosome euploidy and clinical pregnancy rates of 237 blastocysts from 50 pre-implantation genetic diagnosis (PGS) cycles were statistically analyzed. The corresponding euploidy rate and pregnancy outcomes of the D5 and D6 blastocyst transfers were also compared.

Results

The clinical pregnancy rate (47.2 vs 40.0 %; P?=?0.04) and implantation rate (34.2 vs 28.8 %; P?=?0.03) of the D5 blastocysts were higher than were those of the D6 blastocysts. However, the clinical pregnancy rate (52.4 vs 52.6 %; P?=?0.97) and implantation rate (38.9 vs 35.6 %; P?=?0.39) of the high-quality D5 blastocysts did not significantly differ from those of the high-quality D6 blastocysts. Analysis of blastocyst euploidy in 237 blastocysts examined in 50 PGS cycles showed that the euploidy rates of the D5 and D6 blastocysts were both 48.1 % (P?=?0.99). The clinical pregnancy rate of the D5 blastocysts (48.5 vs 17.6 %; P?=?0.03) was higher than that of the D6 blastocysts. The euploidy rates (55.2 vs 55.3 %; P?=?0.99) and clinical pregnancy rates (60.0 vs 42.9 %; P?=?0.77) of the high-quality D5 and D6 blastocysts did not differ. The euploidy rate (55.3 vs 41.5 %, P?=?0.03) and clinical pregnancy rate (54.5 vs 25.0 %, P?=?0.03) of the high-quality blastocysts were higher than were those of the poor-quality blastocysts.

Conclusions

The euploidy rates between the D5 and D6 blastocysts did not differ. High-quality D6 blastocysts in frozen-thawed cycles had similar developmental potential and pregnancy outcomes compared to those of high-quality D5 blastocysts. The quality of the blastocysts was an important factor that affected the pregnancy outcomes of the frozen-thawed cycles.

     

Correlation between the pronucleus size and the potential for human single pronucleus zygotes to develop into blastocysts

Purpose

In this study, we examined the correlation between pronucleus size and the potential for human single pronucleus (1PN) zygotes to develop into blastocysts after IVF and ICSI.

Methods

This study included 112 patients who underwent a total of 112 cycles of IVF/ICSI. To evaluate embryo development, 1PN zygotes were compared with 2PN zygotes in the same IVF/ICSI cycle (control cycles) using time-lapse live embryo imaging. To assess the potential for blastocyst formation, cutoff values for pronuclear area and diameter were established through receiver operating characteristic curve analysis, after which 1PN zygotes were classified based on those cutoff values.

Results

Among 1PN zygotes cultured to day 5/6, the rate of embryo development was significantly lower than from 2PN zygotes. However, the rates of blastocyst formation and good quality blastocysts from 1PN zygotes with large pronuclear areas (≥?710 μm²) or diameters (≥?31 μm) were significantly higher than from 1PN zygotes with smaller pronuclear areas (≤?509, 510–609, and 610–709 μm²) or diameters (≤?24, 25–27,and 28–30 μm) (P?<?0.01). Moreover, the results for 1PN zygotes with large pronuclei were similar to those for 2PN zygotes.

Conclusions

The developmental potential of 1PN zygotes with large pronuclear areas (≥?710 μm²) or diameters (31 μm) appears to be similar to that of 2PN zygotes, and measurement of pronuclear area or diameter in 1PN zygotes is a simple, potentially useful, clinical method.

     

The presence of 1 mM glycine in vitrification solutions protects oocyte mitochondrial homeostasis and improves blastocyst development

Purpose

Embryos generated from oocytes which have been vitrified have lower blastocyst development rates than embryos generated from fresh oocytes. This is indicative of a level of irreversible damage to the oocyte possibly due to exposure to high cryoprotectant levels and osmotic stress. This study aimed to assess the effects of vitrification on the mitochondria of mature mouse oocytes while also examining the ability of the osmolyte glycine, to maintain cell function after vitrification.

Methods

Oocytes were cryopreserved via vitrification with or without 1 mM Glycine and compared to fresh oocyte controls. Oocytes were assessed for mitochondrial distribution and membrane potential as well as their ability to fertilise. Blastocyst development and gene expression was also examined.

Results

Vitrification altered mitochondrial distribution and membrane potential, which did not recover after 2 h of culture. Addition of 1 mM glycine to the vitrification media prevented these perturbations. Furthermore, blastocyst development from oocytes that were vitrified with glycine was significantly higher compared to those vitrified without glycine (83.9 % vs. 76.5 % respectively; p?<?0.05) and blastocysts derived from oocytes that were vitrified without glycine had significantly decreased levels of IGF2 and Glut3 compared to control blastocysts however those derived from oocytes vitrified with glycine had comparable levels of these genes compared to fresh controls.

Conclusion

Addition of 1 mM glycine to the vitrification solutions improved the ability of the oocyte to maintain its mitochondrial physiology and subsequent development and therefore could be considered for routine inclusion in cryopreservation solutions.     

Vitrification of human embryos subjected to blastomere biopsy for pre-implantation genetic screening produces higher survival and pregnancy rates than slow freezing

Purpose

Cryopreservation of blastocysts, especially those subjected to the trauma due to blastomere biopsy for the purposes of pre-implantation genetic screening (PGS), requires significant optimization. Laboratory and clinical outcomes were compared to determine the effect of two different cryopreservation techniques on the development of human pre-implantation embryos that underwent blastomere biopsy and blastocoel drainage prior to cryopreservation.

Design

Retrospective clinical study.

Patient(s)

Women who requested cryotransfer of supernumerary blastocysts were analyzed by FISH.

Results

The main outcome measures were post-thaw survival (SR), pregnancy (PR), and implantation (IR). The SR of slowly frozen blastocysts was 83% compared to 97% for vitrified blastocysts. In 160 cases where biopsied embryos were cryotransferred, the results for slowly frozen versus vitrified blastocysts were: SR (71% vs. 95%), PR (23% vs. 37%), and IR (26% vs. 36%, P?<?0.05), respectively.

Conclusion

The results revealed that vitrified blastocysts provided higher SR, PR and IR as compared to slowly frozen counterparts.     

Misoprostol Vs Mifepristone and Misoprostol in Second Trimester Termination of Pregnancy

Objective

The present study was conducted with the aim to assess and comparatively evaluate the safety and efficacy of misoprostol alone and mifepristone with misoprostol for second trimester termination of pregnancy.

Methods and Materials

The study was conducted on 200 selected cases, divided in two groups of 100 cases each. In the study group mifepristone was given 200 mg 12 h before intravaginal insertion of 600 μg of misoprostol followed by 400 μg every 3 h up to a maximum of 5 doses or until the abortion occurs, whichever occurs early. In the control group only misoprostol was inserted in the same dose regime. The results were analyzed.

Results

The success rate in both regimens was 100%. Mean induction abortion interval from the insertion of the first misoprostol tablet was significantly shorter in the mifepristone pretreated group 6.72 ± 2.26 h as compared to 12.93 ± 3.4 h in the misoprostol alone group (P < 0.001). The mean blood loss was slightly higher in the control group. The mean dose of the misoprostol required was significantly less in the study group 1,186 ± 291.64 μg as against 1,736 ± 320.20 μg (P < 0.001). The side effects observed in both the groups were similar mainly nausea vomiting, fever, abdominal cramps.

Conclusion

Pretreatment with mifepristone 12 h before intravaginal misoprostol significantly improves the induction abortion interval.     

Survival and post-warming in vitro competence of human oocytes after high security closed system vitrification

Purpose

To compare two vitrification methods and two warming methods for human oocyte vitrification using a high security closed device in terms of survival, fertilization and embryo development.

Methods

For vitrification, oocytes were (1) immediately placed in equilibration solution or (2) they were gradually exposed to the cryoprotectants. For warming, oocytes were placed (1) in a 25 μl preheated (37 °C) thawing solution droplet that was put at room temperature for 1 min once the oocytes were inside or (2) in a 150 μl droplet for 1 minute at 37 °C.

Results

Survival and preimplantation development were significantly lower when warming was performed in a small preheated droplet. There was no significant difference in survival and embryo development between the gradual or direct exposure to cryoprotectants.

Conclusions

Using this high security closed vitrification device a 90 % survival rate can be achieved when the oocytes are immediately warmed in a large volume at 37 °C.     

Pregnancy rates for single embryo transfer (SET) of day 5 and day 6 blastocysts after cryopreservation by vitrification and slow freeze

Purpose

The purpose of this study was to compare clinical and ongoing pregnancy rates in cycles with single embryo transfer (SET) of blastocysts cryopreserved on day 5 or day 6. Our aim was to determine whether day 6 blastocysts perform adequately to recommend SET.

Methods

Retrospective cohort study including 468 transfer cycles for 392 women younger than age 38 undergoing SET at a university-affiliated IVF clinic in the USA. A total of 261 day 5 blastocysts and 207 day 6 blastocysts for frozen-thawed SET between 2010 and 2016 were analyzed. Data included cryopreservation by both a slow freeze method and vitrification.

Results

In total, 59.0% of day 5 SET cycles resulted in a clinical pregnancy compared to 54.1% of day 6 blastocysts (p = 0.54). Ongoing pregnancy rates from day 5 frozen-thawed blastocysts (51.7%) were comparable to day 6 (44.9%, p = 0.14). When looking at vitrified blastocysts only, there were no significant differences between day 5 and day 6 blastocysts, with a clinical pregnancy rate of 69.2% for day 5 and 72.5% for day 6 (p = 0.68).

Conclusions

SETs of day 6 cryopreserved blastocysts resulted in similar clinical and ongoing pregnancy rates compared to day 5, particularly after vitrification.

     

Aneuploidy rates and blastocyst formation after biopsy of morulae and early blastocysts on day 5

Purpose

Studies have demonstrated high implantation rates after trophectoderm biopsy of day 5 expanded blastocysts. However, biopsy of cleavage stage embryos may adversely affect embryo development and implantation. No studies have assessed the utility of day 5 morulae and early blastocyst biopsy. This study sought to better understand these slower embryos’ aneuploidy rates and implantation potential.

Methods

This was a retrospective review of all autologous IVF cycles utilizing PGS at a single academic infertility center.

Results

The biopsy of day 5 morulae and early blastocysts provided 22 % additional euploid blastocysts available for fresh day 6 transfer compared to day 5 biopsy of only expanded blastocysts. Aneuploidy did correlate with embryo stage on day 5, even after controlling for maternal age, with 16 % of morulae and 35 % of blastocysts being euploid. The majority (83 %) of euploid morulae progressed to the blastocyst stage by day 6. Experience transferring slower developing embryos is limited, but preliminary pregnancy and implantation rates appear similar to euploid embryos biopsied as expanded blastocysts.

Conclusions

The biopsy of all non-arrested embryos on day 5 provides genetic information for all blastocysts on day 6, increasing the pool of euploid blastocysts available for fresh transfer and avoiding the need to cryopreserve developmentally competent embryos without genetic information.