Mònica Parriego

Birth after transfer of frozen-thawed vitrified biopsied blastocysts

Purpose: To present a case describing the birth of a healthy female after the replacement of vitrified biopsied embryos after Preimplantation Genetic Diagnosis.Method: A descriptive case report of a single patient.Results: Our patient carrier of an X-linked disease became pregnant and as a result a healthy girl was born.Conclusions: This report shows that blastocysts obtained from biopsied embryos can be successfully cryopreserved by a simple, secure and low-cost vitrification method using a Hemi-straw support.

Preimplantation genetic diagnosis in patients with male meiotic abnormalities.

Indications and candidates for preimplantation genetic diagnosis (PGD) have increased in recent years. This study evaluates whether IVF-intracytoplasmic sperm injection (ICSI) results could be improved by selecting embryos through PGD-AS (aneuploidy screening) in couples in whom the male partner presents meiotic abnormalities. Two hundred and fifty-six embryos were biopsied and 183 were suitable for analysis (73.2%). Ninety-two embryos showed normal chromosomal analysis (50.3% of the analysed embryos and 57.5% of the diagnosed embryos). Pregnancy, abortion and implantation rates were compared with 66 IVF-ICSI cycles performed in 44 patients with meiotic abnormalities without PGD (control group). No statistically significant differences in the pregnancy rate (52 versus 43.9%), implantation rate (32.1 versus 23.5%) and miscarriage rate (15.4 versus 10.3%) were observed between the groups. Although the embryos obtained from men with meiotic abnormalities showed a high frequency of chromosome abnormalities, no improvements in pregnancy and implantation rates were obtained after PGD-AS in the series analysed.

The importance of good practice in preimplantation genetic screening: critical viewpoints

ger association between prenatal depressive symptoms and the risk of preterm delivery. With regard to the subtypes of preterm delivery, unfortunately, we did not have such information for that study. However, as with the potential misclassification of depressive symptoms, the effect of potential misclassification of outcomes (i.e. assuming that depression during pregnancy is only related to certain subtype(s) of preterm delivery) is to attenuate the observed association. In other words, had we only included the subtypes that are associated with depressive symptoms during pregnancy, the observed association would have been stronger.

Pronuclear morphology, embryo development and chromosome constitution

The aim of the present study was to evaluate the usefulness of pronuclear patterns, according to the classifications of Tesarik and Scott, as predictors of embryo chromosome constitution. Up to 73 preimplantation genetic diagnosis/preimplantation genetic screening (PGD/PGS) cycles were analysed in this retrospective study including 17 cycles of translocation carriers and 56 PGS cycles. A total of 331 biopsied embryos were studied assessing pronuclear (PN) pattern, embryo quality and chromosome constitution. As regards to the relationship between PN pattern and embryo quality, the data obtained in this study show no correlation between both parameters. Although there were no significant differences when comparing the distribution of chromosomally normal and abnormal embryos with respect to embryo quality, such differences were observed when distinguishing between normal, aneuploid and polyploid embryos. The results show that the PN pattern using Tesariks and Scotts classification systems is not related to the embryo developmental potential or its chromosome constitution. Therefore, in the context of a PGD/PGS programme, the PN pattern cannot be used as a tool to predict embryo quality or chromosome status.

Could monopronucleated ICSI zygotes be considered for transfer? Analysis through time-lapse monitoring and PGS

PurposeThe purpose of this study was to investigate the chromosomal constitution and the developmental potential of intracytoplasmic sperm injection (ICSI) deriving embryos displaying a single pronucleus at the zygote stage.MethodsEighty-eight embryos from single pronucleus (1PN) two polar bodies (2PB) ICSI zygotes from 64 preimplantational genetic screening (PGS) cycles (October 2012–December 2014), were retrospectively analyzed. Zygotes were cultured in a time-lapse incubator. Embryo biopsy was performed on day 3 and genetic analysis approached by array comparative genomic hybridization.ResultsChromosomal analysis revealed that 17% (15/88) of embryos derived from 1PN 2PB zygotes were diagnosed as euploid. After blastomere biopsy at day 3, the blastocyst rate at day 5 was 3.4% (3/88). Only 2.3% (2/88) euploid blastocysts were obtained. In two couples and after counseling and patient agreement, the transfer of a euploid blastocyst from a 1PN 2PB ICSI zygote was performed resulting in the birth of a healthy child.ConclusionsThese results open the possibility to consider embryos coming from 1PN 2PB ICSI zygotes for transfer when no other embryos from 2PN 2PB ICSI zygotes are available and if a PGS diagnosis of euploidy is obtained. Confirmation of biparental inheritance is strongly recommended.

Oligonucleotide arrays vs. metaphase-comparative genomic hybridisation and BAC arrays for single-cell analysis: first applications to preimplantation genetic diagnosis for Robertsonian translocation carriers.

Comprehensive chromosome analysis techniques such as metaphase-Comparative Genomic Hybridisation (CGH) and array-CGH are available for single-cell analysis. However, while metaphase-CGH and BAC array-CGH have been widely used for Preimplantation Genetic Diagnosis, oligonucleotide array-CGH has not been used in an extensive way. A comparison between oligonucleotide array-CGH and metaphase-CGH has been performed analysing 15 single fibroblasts from aneuploid cell-lines and 18 single blastomeres from human cleavage-stage embryos. Afterwards, oligonucleotide array-CGH and BAC array-CGH were also compared analysing 16 single blastomeres from human cleavage-stage embryos. All three comprehensive analysis techniques provided broadly similar cytogenetic profiles; however, non-identical profiles appeared when extensive aneuploidies were present in a cell. Both array techniques provided an optimised analysis procedure and a higher resolution than metaphase-CGH. Moreover, oligonucleotide array-CGH was able to define extra segmental imbalances in 14.7% of the blastomeres and it better determined the specific unbalanced chromosome regions due to a higher resolution of the technique (≈20 kb). Applicability of oligonucleotide array-CGH for Preimplantation Genetic Diagnosis has been demonstrated in two cases of Robertsonian translocation carriers 45,XY,der(13;14)(q10;q10). Transfer of euploid embryos was performed in both cases and pregnancy was achieved by one of the couples. This is the first time that an oligonucleotide array-CGH approach has been successfully applied to Preimplantation Genetic Diagnosis for balanced chromosome rearrangement carriers.

Usefulness of oocyte accumulation in low ovarian response for PGS

Abstract This is an observational study of the response to ovarian stimulation and preimplantational genetic screening (PGS) cycles of 188 patients with a foreseen high aneuploid rate, undergoing two or three stimulation cycles (2SC and 3SC) and oocyte vitrification to accumulate oocytes (Accumulation group = 112 patients) compared to patients undergoing one stimulation cycle (1SC Group= 76 patients) and fresh embryo transfer, between January 2011 and July 2014. Accumulation was performed when <10 MII oocytes were retrieved. Oocytes were vitrified for later warming and IVF, when the planned number of oocytes was achieved. After PGS, euploid embryos were transferred. Comparing 2SC Group with 3SC Group, AMH, AFC, number of oocytes retrieved per pick-up and total number of biopsied embryos were significantly higher in the 2SC Group. After chromosome analysis, 18.5% of biopsied embryos were euploid and 58.9% patients reached embryo transfer. There were no differences in pregnancy rates per patient between the 1SC, 2SC and 3SC Groups (36.8%, 34.9% and 31.0%, respectively) or per embryo transfer (59.6, 56.8 and 60%, respectively). In patients with <10 MII oocytes after ovarian stimulation undergoing PGS, accumulating oocytes can render a pregnancy rate per patient and per embryo transfer comparable to those of fresh PGS cycles.

Linking back-to-back stimulation cycles with oral contraceptives or progestins in women undergoing embryo accumulation for preimplantation genetic testing, a retrospective study

Abstract This retrospective study was carried out to determine which strategy is associated with improved outcomes in two back-to-back cycles when undergoing embryo accumulation. Eighty patients with two stimulation cycles performed with <45 days between retrievals between Jan’16-Mar’17 were included. Patients were segregated according to the strategy used to link stimulations: spontaneous menses (SM), vaginal micronized progesterone (VMP) or oral contraceptive pills (OCP). Main outcome measure was oocytes retrieved. The oocytes retrieved difference between cycles was −0.9 in SM, −1.5 in VMP and +0.4 in OCPs. Although not statistically significant, more oocytes retrieved were observed in the 2ndcycle when OCPs were used (9.0 ± 3.7 vs. 9.4 ± 4.1)? whereas fewer oocytes retrieved were observed when SM (9.4 ± 3.9 vs. 8.5 ± .0) or VMP (9.8 ± 5.7 vs. 8.2 ± 4.4) were used. After adjusting for age, gonadotropins and stimulation days (2nd cycle) and treatment group in an ANCOVA model, no treatment was associated with a higher average number of oocytes retrieved (power: 14.9%) or a higher difference of oocytes retrieved (power: 22.3%). Although no statistical significance was reached, OCPs were observed to achieve higher average and positive difference of oocytes retrieved in the 2nd cycle. 摘要 本项回顾性研究旨在确定在接受胚胎积累女性的两个连续刺激周期中, 哪种策略与改善结局相关。经检索在1月16日至3月17日之间进行两次＜45天刺激周期的患者共有80例。根据不同刺激策略对患者进行以下分组：自发性月经（spontaneous menses, SM）、阴道微粒化黄体酮（vaginal micronized progesterone, VMP）和口服避孕药（oral contraceptive pills, OCP）。主要观察指标为获卵数。周期间获卵数的差异在SM组为-0.9, VMP组为-1.5, OCPs组为+0.4。尽管没有统计学意义, 但OCPs组在第2周期中可观察到更多的获卵数（9.0±3.7和9.4±4.1）；相反, SM组（9.4±3.9和8.5±.0）和VMP组（9.8±5.7和8.2±4.4）则观察到相对较少的获卵数。在协方差分析模型中, 调整年龄、促性腺激素及刺激天数（第2周期）和治疗组后, 未发现不同治疗与高平均获卵数（power：14.9%）或获卵数存在明显差异（power：22.3%）相关。尽管未达到统计学意义, 但观察到OCPs组在第2周期中平均获卵数和阳性差异更高。

Inconclusive results in preimplantation genetic testing: go for a second biopsy?

Abstract The transition in biopsy timing from blastomere to trophectoderm biopsy has led to a remarkable decrease in the percentage of undiagnosed blastocysts. However, patients with few or no euploid blastocysts can be affected by this residual percentage of diagnosis failure. The aim of this study is to assess whether blastocyst rebiopsy and revitrification is an efficient and safe procedure to be applied in cases of no results after analysis. Fifty-three patients agreed to the warming of 61 blastocysts to perform a second biopsy and PGT-A by aCGH. Only 75.4% of the blastocysts survived, reexpanded, and could be rebiopsied. After the second biopsy and analysis, 95.6% of the blastocysts were successfully diagnosed with an euploidy rate of 65.9%. Eighteen euploid blastocysts were warmed and transferred to 18 patients with a 100% survival and reexpansion rate. Seven clinical pregnancies have been achieved with 4 live births, 1 ongoing pregnancy, and 2 miscarriages. Thus, although few transfers of rebiopsied and revitrified blastocysts have been performed till date, our preliminary results show that this approach is efficient and safe to be applied for undiagnosed blastocysts, as it ultimately allows the transfer of euploid blastocysts and good clinical outcomes.