The embryos that did not develop to blastocyst on day 6 were considered arrested, and up to five blastomeres were biopsied from these embryos. The biopsied cells were washed with a washing buffer, placed in tubes with cell lysis buffer and then frozen before being processed for microarray. The Agilent array platform was used to examine the chromosomes in the samples.
The application of the Agilent DNA microarray platform in human embryos has been validated in the previous study, and the results were comparable to those obtained with other DNA microarray platforms, including the most common BluGnome platform [ 26 , 27 ].
Labeled samples were then mixed with Cy5 control labeled samples. Scanned images were analyzed by Cytogenomics software following Agilent comparative genomic hybridization CGH data analysis protocol. A total of 90 embryos from 17 patients were analyzed after biopsy and microarray. As shown in Table 1 , 14 We categorized these patients into two groups based on their maternal ages and years old.
As shown in Table 1 , the aneuploid rate PGS charts of human embryo samples with different types of chromosome abnormalities analyzed by the Agilent DNA array platform. A An arrested embryo had euploid cells with partial chromosome deletion 46, XX, Del 1p. C An arrested embryo had multiple 44, XY, , chromosome errors. D A blastocyst had multiple chromosomal abnormalities. Arrows indicate chromosome errors.
When we analyzed the relationship between the developmental potential of embryos and maternal age, we found that the blastocyst rate When the relationship between the developmental potential of embryos and their chromosome integrity was examined, it was found that This suggests that aneuploidy could significantly decrease the developmental potential of embryos. The development of aneuploid and euploid embryos.
The rates of blastocysts and arrested embryos in aneuploid and euploid embryos were calculated respectively.
Blastocysts were examined on day 5 and day 6 after fertilization, and chromosomes were examined by DNA microarray.
As aneuploidy significantly influences embryo development, we predicted that more arrested embryos would be aneuploid. Indeed, as shown in Figure 3 , we found that 44 out of 45 arrested embryos When we further examined the chromosome distribution and the types of aneuploidies in the aneuploid embryos, as shown in Figure 4 , we did not find significant differences in the chromosomal distribution between blastocysts and arrested embryos in terms of monosomy 25 vs However, more arrested embryos had multiple chromosomal abnormalities complex: Errors occurred randomly in chromosomes, and there was no obvious difference between blastocysts and arrested embryos.
The proportions of aneuploidy in the developing embryos and arrested embryos. Embryo stages were examined on day 5 and day 6 after fertilization, and chromosomes were examined by DNA microarray.
Microarray results of abnormal chromosomes in blastocysts and arrested embryos. A Abnormal chromosome distribution in the blastocysts and arrested embryos. Anomalies include monosomy, trisomy and complex multiple chromosome errors. B Distribution of chromosomal errors in the blastocysts.
C Distribution of chromosome errors in the arrested embryos. In the present study, we examined all 23 pairs of chromosomes in both blastocysts and arrested embryos from the same cycle in patients undergoing IVF and PGS by DNA microarray. The results indicate that almost all arrested embryos are aneuploid and the occurrence of aneuploidy in the blastocysts is closely related with maternal age.
It is well known that advanced maternal age is correlated with higher rates of embryonic aneuploidy [ 3 - 7 ].
In the present study, we found that a high proportion These results were consistent with those reported previously by others [ 2 , 3 , 5 , 7 , 8 , 22 , 23 , 28 ]. However, the aneuploid rate observed in the present study was higher than those reported in the previous studies [ 2 , 3 , 22 , 23 ]. One of the reasons for this high aneuploid rate in the arrested embryos may be due to the small sample size observed in the present study; thus the data may not represent larger populations of IVF patients.
Another reason may be due to the embryo quality and patient population. The arrested embryos in the present study stopped development on day 3, but the biopsy and DNA array test were performed on day 6. Thus, the prolonged culture may have caused DNA degeneration or damages; this may also be an explanation of why more arrested embryos had multiple complex chromosomal abnormalities than blastocysts. Patient ages may be the major factor causing aneuploid formation in the present study. We had a similar patient population in this study, but the aneuploid rate was higher than the results reported previously [ 3 ].
We examined all chromosomes but only 7 chromosomes were examined in the previous study [ 3 ]. Aneuploidy could lead to reduced implantation and high miscarriage rates, but little is known about its mechanisms. However, it is not known whether aneuploidy can directly influence embryo development. In the present study, we compared chromosome errors in the blastocysts and arrested embryos at various earlier stages and it was found that more euploid embryos developed to blastocyst than aneuploid embryos.
These results indicate that aneuploidy can affect embryo development. We also found that not only more arrested embryos were aneuploid, but also more chromosomes had errors in the arrested embryos than in blastocysts. They found that the rate of in vitro maturation was significantly higher in the hCG-primed group There were no significant differences in the clinical pregnancy rate This might be related to the stage of embryo that was transferred, since blastocyst embryos were transferred in frozen ET cycle while cleavage embryos were transferred in fresh ET cycles.
According to natural selection, only good quality cleavage embryos have the ability to develop to the blastocyst stage. Thus, this might be related to asynchrony between the state of the endometrium and the IVM embryos.
Unfortunately, it was associated with an increased rate of early embryo arrest during the third cytokinesis Day 3—4 stage compared to the ICSI group [ 15 ]. In conclusion, a better understanding and improvement of IVM procedure is still needed. Recently, Lei et al. Unlike in vivo maturation, which was accompanied by increased cAMP levels, which in turn, induced epidermal growth factor EGF -like peptide expression in cumulus cells leading to cumulus expansion and oocyte maturation, in vitro maturation of oocytes is a spontaneous process due to decreased EGF-like peptides that result from a sudden drop in immature COC cAMP [ 43 , 44 , 45 , 46 ], which might account for the lower mitochondrial function.
On the other hand, in animal studies, supplementation with EGF-like peptides significantly increased mitochondrial activity in oocytes matured in vitro through enhanced glucose metabolism and protein glycosylation, which in turn, increased the developmental competence of oocytes and blastocyst formation rate [ 47 , 48 ]. Also, the pre-maturation stage with cAMP modulators and EGF-like peptides in the IVM technique could attenuate spontaneous oocyte maturation and extend cumulus oocyte gap-junction, resulting in a significant increase in oocyte developmental competence [ 46 , 49 , 50 ].
Based on the above evidence, the IVM-associated high rate of early embryonic arrest might be attributed to mitochondrial dysfunction. Thus, further laboratory investigations with large samples in human are still needed to improve the clinical efficiency of mitochondrial nutrients that can be added to IVM culture medium.
To exclude the possible effect of ovarian hyperstimulation on the aneuploidy rate, Labarta et al. While, Benkhalifa et al. Although the incidence of aneuploidy greatly varies in the two studies, the smaller number of chromosomes screened, a main limitation of FISH, different IVM protocols that were applied, and variations between participants normal oocyte donors and PCOS women may account for the observed differences. Recently, using LSCM, several studies reported that in vitro culture had no impact on the IVM efficiency or the frequency of meiotic anomalies in POCS patients compared to controls, but they reported an increase in the percent of meiotic anomalies, which suggested that IVM itself might cause an increase in the incidence of meiotic abnormalities that then resulted in chromosomal disorders [ 56 , 57 ].
The sequencing results showed that the aneuploidy rates were comparable 75, 75, and Therefore, aneuploidy does not appear to be the predisposing reason for the high incidence of early embryo arrest in IVM cycles. In addition, frozen and thawed ET cycles had a higher clinical pregnancy and implantation rate compared to that of fresh ET cycles. Thus, it is necessary to pay more attention to the possibility of asynchrony between the endometrium and the embryos.
Therefore, we concluded that IVM itself adversely affected oocyte and embryo development by affecting mitochondrial function that seemed to be the possible cause for lower blastocyst formation rates in IVM cycles. Further laboratory investigations with larger sample sizes are still needed to improve IVM oocyte and embryo competence in vitro culturing. Clinical definition paper on in vitro maturation of human oocytes.
Hum Reprod. Natural-cycle in vitro fertilization combined with in vitro maturation of immature oocytes is a potential approach in infertility treatment. Fertil Steril. PubMed Google Scholar. New alternative to infertility treatment for women without ovarian stimulation. Reprod BioMed Online.
Laboratory and embryological aspects of hCG-primed in vitro maturation cycles for patients with polycystic ovaries. Hum Reprod Update. State of the art in in-vitro oocyte maturation. Curr Opin Obstet Gynecol. In vitro maturation in subfertile women with polycystic ovarian syndrome undergoing assisted reproduction. Cochrane Database Syst Rev. Embryological aspects of oocyte in vitro maturation. Int J Mol Cell Med. Human chorionic gonadotropin for in vitro oocyte maturation: does it improve the endometrium or implantation?
J Reprod Med. Junk SM, Yeap D. Improved implantation and ongoing pregnancy rates after single-embryo transfer with an optimized protocol for in vitro oocyte maturation in women with polycystic ovaries and polycystic ovary syndrome. Estrogen-suppressed in vitro maturation: a novel approach to in vitro maturation. Human chorionic gonadotrophin priming for fertility treatment with in vitro maturation. Facts Views Vis Obgyn. In vitro maturation as an alternative to standard in vitro fertilization for patients diagnosed with polycystic ovaries: a comparative analysis of fresh, frozen and cumulative cycle outcomes.
In vitro maturation is associated with increased early embryo arrest without impairing morphokinetic development of useable embryos progressing to blastocysts. Impact of PCOS on early embryo cleavage kinetics. Clinical validation of embryo culture and selection by morphokinetic analysis: a randomized, controlled trial of the EmbryoScope. Preimplantation aneuploidy testing for infertile patients of advanced maternal age: a randomized prospective trial.
The effects of oxidative stress on female reproduction: a review. Reprod Biol Endocrinol. Van Blerkom J. Mitochondrial function in the human oocyte and embryo and their role in developmental competence. Chromosomal aneuploidies and early embryonic developmental arrest.
After all that anticipation, all the drugs, all the appointments, it is entirely possible to end up with no embryos. What is more common, and so difficult, is to get the phone call saying none of the embryos survived and made it to day 5.
So why do embryos arrest? Although we cannot change our age, many factors that impact egg and sperm quality can be modified through diet and lifestyle changes. Previous Next. This is one of the most heartbreaking moments; a patient is told they have no viable embryos available for a transfer upon completing a round of IVF.
There is hindrance of cell division and cells stop growing when there is suboptimal conditions in the lab.
Environment and air of IVF labs need to be clean and free from any pollutants. Volatile organic compounds VOCs like Ethanol, isopropyl alcohol for decontaminating surfaces , Propene, acetonitrile, styrene from plastics , Formaldehyde, acetaldehyde found in paints, gasoline, smog are molecules in the air that can be harmful to embryos. VOCs have been linked to embryo arrest or failure to develop blastocysts as well as reduced overall success Mortimer et al.
Talk to the best team of fertility experts in the country today for all your pregnancy and fertility-related queries. Select State. Select City. Inline Feedbacks. October 18, It is the condition when October 12, At Indira IVF, we advocate Most women who have PCOS October 11, Experts at Indira IVF know October 5, Our fertility experts know that There are multiple reasons for October 1,
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