Selecting embryos with the highest implantation potential using data mining and decision tree based on classical embryo morphology and morphokinetics

Purpose

The objective of this work was to determine which embryonic morphokinetic parameters up to D3 of in vitro development have predictive value for implantation for the selection of embryos for transfer in clinical practice based upon information generated from embryo transfers with known implantation data (KID).

Methods

A total of 800 KID embryos (100% implantation rate (IR) per transfer and 0% IR per transfer) cultured in an incubator with Time-Lapse system were retrospectively analysed. Of them, 140 embryos implanted, whereas 660 did not.

Results

The analysis of morphokinetic parameters, together with the embryo morphology assessment on D3, enabled us to develop a hierarchical model that places the classical morphological score, the t4 and t8 morphokinetic values, as the variables with the best prognosis of implantation.

Conclusion

In our decision tree, the classical morphological score is the most predictive parameter. Among embryos with better morphological scores, morphokinetics permits deselection of embryos with the lowest implantation potential.

     

Morphokinetic parameters from a time-lapse monitoring system cannot accurately predict the ploidy of embryos

Purpose

This study aimed to test whether there is an association between embryo morphokinetic parameters and ploidy status.

Methods

Patients with high risk of aneuploidy were analyzed by time-lapse microscopy combined with preimplantation genetic screening (PGS). Accordingly, 256 blastocysts from 75 patients were subjected to trophectoderm biopsy and microarray comparative genomic hybridization (array-CGH). Blastocyst development process was analyzed using time-lapse images.

Results

Morphokinetic parameters: tPNf, t2, t3, t4, t5, t8, t9, tcom, tM, tSB, tB, tEB, CC1, CC2, CC3, S2, S3, t5-t2, and tB-tSB showed no significant difference in euploid embryos compared to aneuploid counterparts. In addition, two risk models based on previously published morphokinetic parameters failed to segregate euploid from aneuploid embryos.

Conclusions

Morphokinetic parameters subjected to investigation in the present study failed to improve the chance of selecting euploid embryos.

     

The association between coenzyme Q10 concentrations in follicular fluid with embryo morphokinetics and pregnancy rate in assisted reproductive techniques

Purpose

This study seeks to evaluate the association between follicular fluid (FF) coenzyme Q10 (CoQ10) levels, embryo morphokinetics, and pregnancy rate.

Methods

Sixty infertile patients who underwent intracytoplasmic sperm injection (ICSI) cycles were included in the study. For each patient, CoQ10 level of the follicular fluid was measured by high-performance liquid chromatography system. After the ICSI of each oocyte, the relationship between the level of CoQ10 content of each follicular fluid, the subsequent embryo quality, and embryo morphokinetics was investigated. The relationship between the level of CoQ10 content of each follicle and optimal time-lapse parameters for the embryos of these follicles including t5, s2, and cc2 was also analyzed. The embryos were further classified into four categories, namely, grades A, B, C, and D, according to morphokinetic parameters using t5–t2 and t5–t3 (cc3). Each follicular fluid analysis was performed for a single oocyte of a single embryo which was transferred to the patients. Additionally, follicular fluid CoQ10 levels and pregnancy rates were evaluated.

Results

Follicular fluid CoQ10 levels were significantly higher in grades A and B than grades C and D embryos (p?<?0.05). The concentration of CoQ10 levels was significantly higher in the pregnant group (p?<?0.05). There was no significant correlation between optimal t5 and s2 morphokinetic parameters and CoQ10 levels. However, CoQ10 levels were significantly higher in follicular fluid of embryos which had optimal cc2 (p?<?0.05).

Conclusion

High follicular fluid CoQ10 level is associated with optimal embryo morphokinetic parameters and higher pregnancy rates.

     

In vitro maturation (IVM) of oocytes in patients with resistant ovary syndrome and in patients with repeated deficient oocyte maturation

Purpose

To assess the efficiency of IVM in patients with repeated ART failure due to resistant ovary syndrome or due to deficient oocyte maturation.

Methods

Clinical and laboratory data were obtained retrospectively from 28 patients who underwent 49 cycles of IVM between 2010 and 2017; nine patients had resistant ovary syndrome and 19 patients had repeated deficient oocyte maturation.

Results

Nine patients with resistant ovary syndrome underwent 24 IVM cycles. In those, an average of 11.5?±?10.4 cumulus-oocyte complexes (COC) was retrieved, and IVM resulted in 3.4?±?3.1 mature oocytes. After ICSI and transfer of 23 cleavage-stage embryos, eight pregnancies were obtained, resulting in five healthy live births. The live birth rate was 16.7% per started cycle and 33.3% per patient.Nineteen patients with a history of deficient oocyte maturation underwent 25 IVM cycles. An average of 10.6?±?9.2 COC was retrieved, and after IVM, 1.3?±?2.1 oocytes were mature. No mature oocytes were obtained in 11 cycles. In ten cycles with mature oocytes, none of them fertilized after ICSI. Out of four cycles with fertilized oocytes, only one good-quality embryo was obtained. No live births were obtained after IVM in patients with a history of deficient oocyte maturation.

Conclusions

Based on our experience, IVM is a valuable approach in patients with resistant ovary syndrome, but should not be recommended for patients with deficient oocyte maturation.

     

Outcome of gestational surrogacy according to IVF protocol

Purpose

Surrogacy remains the only option for having a biologic child for a unique population of women with severe medical conditions. However, no study has looked at surrogacy outcome as a result of the type of ovarian stimulation of the intended mother [controlled ovarian stimulation (COH), modified natural cycle (MNC), and in vitro maturation (IVM)] for oocyte retrieval.

Methods

This is a retrospective study, including all intended mothers and gestational carriers in a tertiary, university affiliated, medical center, from 1998 to 2016.

Results

Fifty-two women underwent 252 oocyte retrieval cycles. The pregnancy outcome of 212 embryo transfer cycles (64 gestational carriers) was reviewed according to the origin of the embryo. The number of retrieved oocytes was significantly higher following COH (n?=?132) compared with IVM (n?=?58) and MNC cycles (n?=?62) (p?=?0.013 and p?<?0.0001, respectively). Pregnancy rates for embryos transferred according to each protocol were similar. All pregnancies that ended in live births when oocytes from IVM cycles were used derived from transfers of retrieved mature and mixed mature and immature oocytes. Pregnancies that involved embryos derived solely from immature oocytes that further matured in vitro and were transferred to gestational carriers were unsuccessful.

Conclusions

MNC protocol is a good option to achieve pregnancy for intended mothers using gestational surrogacy who have contraindications to COH. The yield of IVM cycles in which immature oocytes are retrieved is inconclusive.

     

Effect of acteoside on the re-localization and abnormal morphology of mitochondria in porcine oocytes during in vitro maturation

Purpose

The aim of this study is to investigate the effect of acteoside, an antioxidant, on in vitro maturation (IVM) of oocytes to improve early parthenogenetic embryonic developmental competence.

Methods

Porcine immature oocytes (total 770) were cultured in IVM medium with acteoside at various concentrations, 0 (control), 10, 30, and 50 μM. Each group was assessed for maturation and subsequent development rates, reactive oxygen species (ROS) level (15 oocytes per group and four independent experiments performed), ultrastructure observation (15 oocytes per group), mitochondrial activity (30 oocytes per groups and three independent experiments performed), and expression patterns of apoptosis-related genes (100 expended parthenogenetic embryos per group and three independent experiment performed). Main outcome measures were the rates of IVM, blastocyst formation, ROS, mitochondria, and expression of apoptosis-related genes in oocytes treated with acteoside.

Result(s)

Addition of acteoside during IVM did not change the maturation efficiency of oocytes but improved the rate of blastocyst formation with significantly decreased ROS level. Moreover, in acteoside-treated oocytes, cytoplasmic maturation was improved with morphologically uniform distribution of mitochondria and lipid droplets in cytoplasm. Acteoside supplementation also increased the mRNA expression levels of antiapoptotic genes and reduced those of pro-apoptotic genes.

Conclusion(s)

Acteoside supplementation in IVM medium improves the oocyte quality and subsequent development of pre-implantation embryos that would eventually contribute to produce embryos with high embryonic development competence.

     

The effect of short-term exposure of cumulus-oocyte complexes to in vitro maturation medium on yield of mature oocytes and usable embryos in stimulated cycles

Purpose

We examined whether short-term exposure to in vitro maturation (IVM) medium of cumulus-oocyte complexes (COCs) from a stimulated cycle increases the yield of metaphase II (MII) oocytes and usable embryos.

Methods

Retrospective review of two consecutive autologous IVF/ICSI cycles per patient between 2007 and 2015 in which cycle 1 did not result in live birth. Patients with short-term exposure of COCs to IVM medium (3–5 h before standard insemination or ICSI) in cycle 2 (treated) were matched 1:4 on %MI and %MII to patients without use of IVM in cycle 2 (untreated). The proportions of mature oocytes, two pronucleate (2PN) zygotes, number of usable embryos, and clinical outcomes were compared between groups with regression modeling.

Results

The treated (n?=?43) and untreated (n?=?163) groups had similar demographic characteristics and similarly high proportions of immature oocytes (48.2 vs. 41.3%, respectively) in cycle 1. There were no significant differences between the treated and untreated groups in the change in %MII (48.1 to 68.9% vs. 50.5 to 72.5%, respectively) or mean number of usable embryos (2.2 to 3.4 vs. 2.0 to 3.3, respectively) from cycle 1 to cycle 2.

Conclusions

These findings suggest that short-term IVM incubation of COCs may not provide any additional benefit in patients with a prior unsuccessful cycle notable for a high proportion of immature oocytes. Further randomized studies are warranted to determine whether there is a subset of patients who may have improved clinical outcomes with this “rescue IVM” intervention.

     

Outcome of immature oocytes collection of 119 cancer patients during ovarian tissue harvesting for fertility preservation

Purpose

Few clinical options for fertility preservation are available to females with cancer, and data about clinical outcomes is limited. Potential supplementary approaches to fertility preservation include retrieval of immature oocytes followed by in vitro maturation (IVM) and storage. The aim of this study was to evaluate post-thawing outcomes of immature oocytes collected both by transvaginal aspiration and from excised ovarian tissue.

Methods

We conducted a retrospective cohort study of patients treated in a single tertiary center. We reviewed the records of 119 cancer patients who underwent ovarian tissue cryopreservation and immature oocyte harvesting for fertility preservation. All embryos and oocytes that were frozen and thawed were included in the study. Post-thawing outcomes were evaluated.

Results

Thirty-five stored embryos from eight patients were thawed. Twenty-nine embryos survived (82% survival rate) and were transferred. Six oocytes were thawed, two oocytes survived, and no oocytes were fertilized. Only one PCOS patient became pregnant, resulting in the normal delivery of a healthy baby.

Conclusions

Although a relatively high number of mature oocytes and embryos can be stored with the combined procedure, the limited rate of pregnancies represents a poor reproductive outcome. Therefore, this approach should be reserved for special groups with limited options.

     

Live births resulting from 0PN-derived embryos in conventional IVF cycles

Purpose

The aim of this study was to (1) investigate the incidence of embryos derived from “unfertilized oocytes” i.e., oocytes not displaying pronuclei (0PN) at the time of the fertilization check and (2) determine the clinical pregnancy rates when transferring 0PN-derived embryos.

Methods

In this retrospective study, 4424 IVF-ET cycles were reviewed.

Results

In total, 11.3 % (4966/43,949) 0PN-derived embryos were observed. It was found that female age, number of oocytes, and the top-quality embryo rate were significantly correlated with 0PN-derived embryo occurrence. The source of embryos transferred did not impact significantly on clinical pregnancy and live-birth rates. Of the 183 cycles included in this study where 275 0PN-derived embryos were transferred in total, only 0PN-derived embryos were available in 70 of those cycles. It was noteworthy that 13 healthy infants resulted from 0PN-derived embryos with an implantation rate of 17.0 %.

Conclusion

These results indicate that the traditional method of excluding embryos because of those oocytes originally lacking any sign of a pronucleus at the fertilization check should be re-considered as transferring 0PN-derived embryos with subsequent expected developmental performance may be considered as an option for those patients where no other embryos are available.

     

Temporal expression of cumulus cell marker genes during in vitro maturation and oocyte developmental competence

Purpose

Cumulus cells (CC) play important roles in oocyte development and cumulus expressed genes can be used as markers for oocyte quality. This study aimed to investigate temporal changes in the expression of cumulus marker genes during oocyte maturation as possible biomarkers of embryo developmental competence in ovine.

Methods

Gene expression was assessed in the CC of the BCB+ (developmentally competent) and BCB- (developmentally poor) oocytes at 0, 12, and 24 h of in vitro maturation (IVM). Further, the association between the temporal cumulus gene expression and in vitro oocyte and embryo development was assessed.

Results

The maturation and blastocyst formation rates were found significantly greater for the BCB+ than the BCB- oocytes. At the 0 h of IVM, a significant upregulation in the expression of PTGS2, STAR, SDC2, LHR, FGF2, BCL2, IL7RA, HSPA1A, and IFNT was observed in the CC of the poor (BCB-) as compared to the competent (BCB+) oocytes. In contrast, it was observed that as maturation progressed, the cumulus expression of most of the favorable genes was reduced and was found significantly downregulated at the completion of IVM in the poor as compared to the competent oocytes.

Conclusions

The study revealed noticeable differences in the cumulus gene expression profile at different stages of IVM between ovine oocytes of differential developmental ability. The results indicated that the loss of cumulus gene expression along the maturation period in the poor oocytes was related to their intrinsic poor quality in the ovarian follicle.

     

Decreased pregnancy and live birth rates after vitrification of in vitro matured oocytes

Purpose

To assess effects on fertilization rate, embryo quality, pregnancy, and live birth rates of vitrification and warming of oocytes that matured in vitro (vIVM) compared to fresh in vitro maturation (fIVM) cycles.

Methods

A retrospective cohort study conducted at a university hospital-affiliated IVF unit. Fifty-six cycles of vIVM cycles and 263 fIVM in women diagnosed with polycystic ovarian syndrome (PCOS) ovaries were included in the analysis. The study group included PCOS patients who failed ovulation induction with intrauterine insemination and were offered IVM cycle followed by oocyte vitrification and warming. The embryological aspects and clinical outcomes were compared to those of controls undergoing fresh IVM cycles during the same period. The main outcome measure was live birth rate.

Results

One thousand seventy oocytes were collected from 56 patients and underwent vitrification and warming. In the control group, 4781 oocytes were collected from 219 patients who had undergone a fresh IVM cycle. Oocyte maturation rates were similar between the groups (mean ± SD: 0.7?±?0.2 vs. 0.6?±?0.2, for vIVM and fIVM, respectively). Survival rate after warming was 59.8%. Fertilization and embryo cleavage rates per oocyte were significantly lower in the vIVM group. Clinical pregnancy (10.7 vs. 36.1%) and live birth rates (8.9 vs. 25.9%) per cycle were significantly lower in the vIVM group than those in the fIVM group (P?=?0.005 and P?<?0.001, respectively). Five healthy babies were born in the vIVM group.

Conclusions

The reproductive potential of vitrified IVM oocytes is impaired. This injury likely occurs through vitrification and warming.

     

Thirteen years’ experience in fertility preservation for cancer patients after in vitro fertilization and in vitro maturation treatments

Purpose

This study aims to describe the experience and outcomes of in vitro maturation without ovarian stimulation (IVM-FP) and conventional in vitro fertilization after ovarian stimulation (IVF-FP) in a fertility preservation (FP) program for women with cancer.

Methods

Retrospective cohort study from 2003 to 2015 was conducted. The study population consisted of 353 women with cancer who underwent 394 FP cycles (187 IVF-FP cycles and 207 IVM-FP) for oocytes and/or embryos cryopreservation.

Result(s)

Comparatively with IVM-FP, IVF-FP had a higher median [25th–75th percentile] number of oocytes collected—12 [8–18] vs 7 [5–13]; oocytes cryopreserved—10 [6–15] vs 5 [2–8]; and, where applicable, embryos cryopreserved—5 [3–7] vs 3 [2–5] (p?<?0.000001). Following FP treatment, 32 patients (9.0%) died, 18 patients (5.6%) conceived spontaneously, and 23 patients (6.5%) returned to attempt pregnancy with a median lapse of returning of 4.6 [3.1–6.1] years. Of these, cryopreserved oocytes or embryos were used in 33 cycles (19 after IVF-FP and 14 after IVM-FP). Overall, the cumulative pregnancy rate (CPR) was 47.6% (10/21) and the live birth rate (LBR) was 38.1% (8/21). Per cycle, CPR and LBR were 37 and 31% following IVF-FP and 14 and 7% following IVM-FP, although these differences did not reach statistical significance. We report the fourth live birth after IVM-FP in cancer, and the first one after IVM embryo warming resulting from in vivo oocyte retrieval and IVM procedure.

Conclusion(s)

Both IVF-FP and IVM-FP are possible options for FP women with cancer. Due to minimal data regarding ultimate outcomes, further follow-up is needed.

     

The total pregnancy potential per oocyte aspiration after assisted reproduction—in how many cycles are biologically competent oocytes available?

Purpose

While stimulation of women prior to assisted reproduction is associated with increased success rates, the total biological pregnancy potential per stimulation cycle is rarely assessed.

Methods

Retrospective sequential cohort study of the cumulative live birth rate in 1148 first IVF/ICSI-cycles and 5-year follow up of frozen embryo replacement (FER) cycles were used. Oocyte number, number of embryos transferred, and cryopreserved/thawed and transferred embryos in a FER cycle were registered for all patients. Children per oocyte and per transferred embryo and percentage of cycles with births were calculated.

Results

We obtained 9529 oocytes. Embryos (2507) were transferred in either fresh or FER cycles, resulting in 422 births and 474 live born children. Median age of the women was 32.5 years (range 20–41.5 years). In total, 34.3 % of all cycles ended with a live birth while in 65.7 % of the cycles, no oocytes were capable of developing into a child. The average number of oocytes needed per live born child after transfer of fresh and thawed embryos was 20 as only 5.0 % of oocytes aspirated in the first IVF/ICSI cycle had the competence to develop into a child.

Conclusions

In our setting, overall 5.0 % of the oocytes in a first cycle were biologically competent and in around 2/3 of all cycles, none of the oocytes had the potential to result in the birth of a child.

     

Bovine in vitro embryo production: the effects of fibroblast growth factor 10 (FGF10)

Purpose

In an attempt to improve in vitro embryo production, we investigated the effect of fibroblast growth factor 10 (FGF10) during in vitro maturation on the developmental capacity of bovine oocytes.

Material and methods

Cumulus–oocyte complexes (COCs) were aspirated from follicles of 3–8 mm diameter. After selection, the COCs were matured in medium with or without 0.5 ng/mL of FGF10. The effect of FGF10 during in vitro maturation (IVM) on nuclear maturation kinetics and expansion of the cumulus cells was investigated. Oocyte competence was assessed by the production and development speed of embryos and the relative expression of genes associated with embryo quality.

Results

FGF10 delayed the resumption of meiosis from 8 h onwards, but did not affect the percentage of oocytes reaching metaphase II, nor did it increase cumulus expansion at 22 h of maturation. We found no difference between treatments regarding embryo production, developmental speed, and gene expression.

Conclusion

In conclusion, the presence of FGF10 during IVM had no effect on embryo production, developmental speed, and gene expression.

     

The accumulation of vitrified oocytes is a strategy to increase the number of euploid available blastocysts for transfer after preimplantation genetic testing

Purpose

In a preimplantation genetic diagnosis for aneuploidy (PGD-A) program, the more embryos available for biopsy, consequently increases the chances of obtaining euploid embryos to transfer. The aim was to increase the number of viable euploid blastocysts in patients undergoing PGD-A using fresh oocytes together with previously accumulated vitrified oocytes.

Methods

Sixty-nine patients with normal ovarian reserve underwent PGD-A for repeated implantation failure or recurrent pregnancy loss indication. After several cycles of ovarian stimulation, 591 accumulated vitrified oocytes and 463 fresh oocytes were micro-injected with the same partner’s semen sample. PGD-A was completed on 134 blastocysts from vitrified/warmed oocytes and 130 blastocysts from fresh oocytes.

Results

A mean of 9.6% euploid blastocyst per micro-injected vitrified/warmed oocytes and 11.4% euploid blastocyst per micro-injected fresh oocyte were obtained (p?>?0.05). The euploidy and aneuploidy rates were comparable in blastocysts obtained from micro-injected vitrified/warmed oocytes and fresh oocytes (42.5 versus 40.8% and 57.5 versus 59.2%, p?>?0.05). Implantation rates of euploid blastocysts were comparable between the two sources of oocytes (56.0% from vitrified/warmed oocytes versus 60.9% from fresh oocytes, p?>?0.05).

Conclusions

Oocyte vitrification and warming do not generate aneuploidy in blastocysts. The number of viable euploid embryos for transfer can be increased by using accumulated vitrified oocytes together with fresh oocytes in ICSI.

Trial registration

NCT02820415 ClinicalTrials.gov

     

Euploid embryos selected by an automated time-lapse system have superior SET outcomes than selected solely by conventional morphology assessment

Purpose

We investigated if automated TLI selection may be a valuable strategy to identify those euploid embryos with the best chances of success.

Methods

This is a unicentric and retrospective study involving 244 patients undergoing preimplantational genetic screening (PGS) cycles with autologous oocytes or oocyte donation (OD) with single euploid embryo transferred. We examined euploid embryos selected for transfer based on morphology evaluation alone (PGS-only; control group) or by assessment using an automated TLI system (Eeva?; PGS-TLI group).

Results

In both, autologous oocytes and OD patients, significantly better implantation and clinical and ongoing pregnancy rates were obtained in the PGS-TLI group when euploid embryos with high implantation potential as predicted by the automated TLI System (Eeva?) were transferred compared with the PGS-only group. This improvement was also observed when only transfers of good morphological quality embryos were compared. TLI categories showed significant differences on blastocyst formation and euploidy rate.

Conclusions

Automated TLI combined with PGS is a useful prognostic tool to identify euploid embryos with the highest potential for implantation and pregnancy. Further, these results provide evidence that a healthy pregnancy does not only depend upon normal chromosomal status.

     

Developmental ability of embryos produced from oocytes with fragile oolemma by intracytoplasmic sperm injection

Purpose

In intracytoplasmic sperm injection (ICSI) of oocytes with a fragile oolemma (fragile oocytes), breakage can occur at injection. In this study, we produced embryos from oocytes with a fragile and normal oolemma (normal oocytes) by ICSI and compared their ability to be fertilized and develop in vitro. We also investigated whether fragile oocyte-derived embryos could implant after blastocyst transfer to determine whether fragile oocytes should be used for assisted reproductive technology treatment.

Methods

Oocytes were divided into three groups—normal oocytes from cycles containing no fragile oocytes (group A), normal oocytes from cycles containing at least one fragile oocyte (group B), and fragile oocytes (group C), and their fertilization abilities after ICSI and the developmental abilities of resultant embryos were compared.

Results

The fertilization rate in group C (65.3 %) was significantly (P?<?0.01) lower than those in groups A (84.6 %) and B (86.9 %), and the degeneration rate in group C (24.2 %) was significantly (P?<?0.01) higher than those in groups A (0.71 %) and B (0.28 %). However, there were no significant differences in the blastocyst formation rates (59.7–67.5 %) of embryos among the different groups. In addition, the pregnancy rate after transfer of blastocysts in group C (50.0 %) was not significantly different from those in groups A (35.6 %) and B (45.8 %).

Conclusions

The fertilization ability after ICSI of fragile oocytes is lower than that of normal oocytes but the resultant embryos have the same developmental ability as those of normal oocyte-derived embryos.

     

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.

     

Blastomere biopsy for PGD delays embryo compaction and blastulation: a time-lapse microscopic analysis

Purpose

The purpose of the study was to explore the effect of blastomere biopsy for preimplantation genetic diagnosis (PGD) on the embryos’ dynamics, further cleavage, development, and implantation.

Methods

The study group included 366 embryos from all PGD treatments (September 2012 to June 2014) cultured in the EmbryoScope? time-lapse monitoring system. The control group included all intracytoplasmic sperm injection (ICSI) embryos cultured in EmbryoScope? until day 5 during the same time period (385 embryos). Time points of key embryonic events were analyzed with an EmbryoViewer?.

Results

Most (88 %) of the embryos were biopsied at ≥8 cells. These results summarize the further dynamic development of the largest cohort of biopsied embryos and demonstrate that blastomere biopsy of cleavage-stage embryos significantly delayed compaction and blastulation compared to the control non-biopsied embryos. This delay in preimplanation developmental events also affected postimplantation development as observed when the dynamics of non-implanted embryos (known implantation data (KID) negative) were compared to those of implanted embryos (KID positive).

Conclusion

Analysis of morphokinetic parameters enabled us to explore how blastomere biopsy interferes with the dynamic sequence of developmental events. Our results show that biopsy delays the compaction and the blastulation of the embryos, leading to a decrease in implantation.

     

Cumulative live birth and surplus embryo incidence after frozen-thaw cycles in PCOS: how many oocytes do we need?

Purpose

This study aimed to evaluate the cumulative live birth rate (CLBR) and surplus embryo rate of polycystic ovarian syndrome (PCOS) patients during in vitro fertilization and embryo transfer (IVF-ET) treatment.

Methods

In this retrospective cohort study, we analyzed 1142 PCOS patients who underwent first IVF in our institution between January 2011 and December 2014. All patients were categorized into five groups according to the number of oocytes retrieved. Main outcomes include CLBR and surplus embryo rate.

Results

A strong correlation was observed between number of oocytes retrieved and CLBR as well as surplus embryo rate in PCOS patients. CLBR was elevated with the increasing number of oocytes and plateaued when oocyte number was up to ten, whereas the surplus embryo rate steadily increased in line with the increase of oocyte number. Patients transferred with frozen embryos showed higher CLBR and LBR during first ET than patients transferred with fresh embryos.

Conclusions

For PCOS patients, retrieving more than ten oocytes leads to no significant benefit to CLBR but generates surplus embryos. Thus, moderate ovarian stimulation should be reconsidered during IVF treatment.