Introduction A potential impact of PGT-A on embryo implantation is often discussed in the reproduction of elderly women with a higher risk of oocyte aneuploidy while its impact is belied in women under 35 years at the same time. The authors studied the influence of PGT-A in egg donation program where the advanced reproductive age and potential oocyte incompetence is mostly excluded. Material and methods In total, 246 embryos were thawed and transferred in egg donation patients of the age category 35 plus in period January 2017 – December 2018. Group A consists of 188 patients with a comprehensive aneuploidy screening (PGT-A), group B consists of 58 patient with no PGT-A. There were performed elective single embryo transfers solely in both groups. Results In group A an implantation rate was 46% (86/188) while in group B 20%(12/58). Natural cycles with triggering ovulation were more successful than the HRT ones (IR 53% resp. 44%). Conclusions The results showed that PGT-A and transfer of euploid embryo improve an implantation rate in egg donation program in the age category 35 plus what is usually disregarded. The number of cycles to pregnancy was lower in case of a euploid embryo was transferred. The major factors involving the implantation rate besides the embryo quality and euploidy are an appropriate endometrial quality and striking the window of implantation (WOI). The implantation rate is slightly better in natural cycles compared to HRT (hormonal replacement treatment) cycles. Among other factors, we reached better results using a longer progesterone administration (minimum 5 days) and a time-lapse monitoring system used in synergy with an embryo selection for the biopsy.

Introduction With the introduction of next generation sequencing (NGS), preimplantation genetic testing of aneuploidies (PGT-A) has become a powerful tool for the selection of euploid embryos, increasing the implantation rate and reducing the risk of pregnancy miscarriage. Due to the higher resolution and dynamic range offered by NGS, the phenomenon of mosaicism and segmental aneuploidies has become challenging for clinical interpretations. Numerous studies have reported live-births after transfer of mosaic embryos, however, only a few studies focused on the clinical relevance of segmental aneuploidies. In our study, we compared various aneuploidy findings among two trophectoderm biopsies and a rest of the embryo. Material and methods In total, 89 embryos previously analyzed with the VeriSeq™ kit were de-vitrified and re-analyzed with the consent of the patients. A second trophectoderm biopsy (TE2) and the rest of the embryo including the inner cell mass (RE) was tubed separately. The TE2 and the RE as well as the amplification product from the original trophectoderm biopsy (TE1) were analyzed using the PG-Seq™ kit. After TE1 reanalysis, 18 biopsies were classified as euploid and the remaining 71 samples had the following aberrations, 62 whole chromosome aneuploid, 32 segmental aneuploid, 26 whole chromosome mosaic and 7 segmental mosaic. Concordance of various aneuploidy types was assessed between TE1, TE2 and RE. Results From the original group of 18 embryo biopsies classified as euploid with TE1, 17 (94.4%) were concordant with TE2 and 16 (88.9%) in RE. Whole chromosome aneuploidy was concordant in 95.2% of cases between TE1-TE2, 93.5% of TE1-RE and 92.3% of TE2-RE with nonconformance generally due to changes in the affected chromosome to segmental aneuploidy or whole chromosome mosaic. In contrast, from 33 individual segmental aneuploidies detected in the original TE1, only 14 of them were observed again in TE2 and RE (42.2%) with 13 changing to euploid. When the TE1 segmental aneuploidy was also manifested in the TE2, it was almost always observed in the RE, with one exception (1/19, 5.3%). Only 1 of 26 (3.8%) TE1 originally found to be whole chromosome mosaic was repeated in the TE2 and 7 in the RE (26.9%). No segmental mosaics were concordant between TE1-TE2 or TE1-ROE and only 1/8 was concordant between TE2-ROE. Conclusions Our study showed that euploid and whole chromosomal aneuploidies have a high predictive value towards the rest of the embryo. In contrast, mosaicism seems to have a low concordance rate between different parts of the embryo, which show us minimal predictive value of the mosaic findings. Interestingly, a 42.2% concordance rate between TE1 and other two parts of the embryo in the group of subchromosomal aneuploidies suggest their clinical potential for healthy live births since these errors may be of mitotic origin. Moreover, and in contrast to mosaics, second embryo biopsy helps to significantly increase the predictive value of segmental aneuploidies towards the rest of the embryo. Further clinical studies are needed, however, a second trophectoderm biopsy of embryos with segmental aneuploidies seems indicated, especially for patients where an euploid embryo is unavailable.

Introduction Karyomapping serves as the universal PGT-M platform based on Mendelian inheritance of SNP markers which assist in identifying haplotypes linked to a mutated gene. Moreover, karyomapping enables detection of aneuploidies by interrogating genome-wide SNP data in embryo samples and assists in a selection of euploid embryos for a transfer. We have found out that high quality SNP profiles, characterized by overall call rate ≥95%, might be reliably used for the identification of mitotic chromosome errors, aneuploidies in mosaic or segmental chromosome aberrations. Since karyomapping utilizes parental DNA samples, the origin of identified aneuploidies might be tracked in embryo samples. Our study describes the incidence and origin of aneuploidy, aiming at segmental chromosomes errors and mosaic aneuploidies which represents hot topic in respect to their clinical significance. Material & methods SNP data obtained by HumanKaryomap-12 BeadChips, Illumina SNP arrays were analysed in 2085 trophectoderm (TE) samples derived from 319 couples requesting PGT-M. Mean maternal age was 32.4 ± 4.5. Based on the karyomapping SNP data QC metrics, mean and median call rate was 90.4% and 95%, respectivelly. In total, 936 embryos fulfilled criteria of high quality SNP profiles (call rate ≥95%). A subset of twenty TE samples detected with mitotic trisomies, mosaic aneuploidies and segmental chromosome abnormalities by karyomapping were reanalysed using PG-Seq™ kit, which is the fully validated PGT-A platform in our laboratory. We have observed full concordance between both platforms. Results Analysing 936 high quality TE samples, we have observed that 617 (65.9%) of them were euploid. The remaining 319 TE samples were detected with the following aberrations: a) only aneuploid 234 (73.4%) samples; b) only mosaic 43 (13.5%) samples; c) aneuploid + mosaic 42 (13.2%) samples. In other words, overall mosaicism rate in 936 TE samples was 9.1% (85/936) in our study. This number tend to be underestimated, since we did not report low level mosaicism due to a lack of proper sensitivity validation of the karyomapping in last years. We have detected segmental aneuploidies in 12.6% (118/936) of TE samples, 56 (47.4%) of them were present in mosaic form. Regarding the origin of aneuploidies, 87% (220/253) of whole chromosome aneuploidies affected maternal chromosomes, the ratio difference was even more highlighted in whole chromosome trisomies (93%; 91 out of 98). In contrast, segmental chromosome abnormalities affected more frequently paternal chromosomes (61,3%; 38 out of 62). Notably, this trend towards paternally related segmental aneuploidies were also followed in segmental chromosome abnormalities in mosaic (60,7%; 34 out of 56). Conclusions 1. According to our validation, high quality SNP profiles (overall SNP call rate ≥95%) enables detection of mitotic trisomies, mosaicism at 25% sensitivity level and segmental chromosome abnormalities (in 5Mb resolution). 2. Meiotic whole chromosome trisomies prevail over mitotic whole chromosome trisomies (in full or mosaic state) in the ratio 4:1. 3. Segmental chromosome abnormalities (in full or mosaic state) affects more frequently paternal chromosomes (P value <0.01). 4. Whole chromosome aneuploidies in mosaic affect equally maternal and paternal chromosomes.

Uvod: V ramci jubilejniho 25. sympozia asistovane reprodukce byl pracovni oběd již posedme organizovaný formou diskuse, ktera se zabývala vybranými tematy asistovane reprodukce. U diskusnich stolů se seslo vice než 150 ucastniků sympozia, kteři diskutovali o aktualnich tematech reprodukcni mediciny. Řesena temata: Vybrana temata se týkala aktualnich otazek z oblasti gynekologie a embryologie. Během oběda byla řesena tato temata: (1) přeshranicni zdravotni pece v asistovane reprodukci, (2) indikace k PGS (preimplantacniho genetickeho screeningu) ve světle nových poznatků, (3) patři stimulace ovarii do ambulanci registrujicich gynekologů? (4) lecba klomifenem – jen pro odborniky v reprodukcni medicině? (5) jak a komu směrovat psychologickou podporu při IVF, (6) stimulace žen s nizkou ovarialni rezervou, (7) je vysetřeni spermiogramu dostacujici? (8) relevantni markery embryonalniho vývoje – time laps system, (9) jak se zorientovat v nabidce medii a spotřebniho materialu v IVF laboratoři a (10) freeze all – nový trend v kryokonzervaci vhodný pro vsechny? Zavěr: Veskere zavěry jednotlivých diskusi byly prezentovany vsem ucastnikům konference v odpolednim bloku a jsou uvedeny v teto praci. Tato cast byla zajimava pro mnoho ucastniků konference a měla hojnou ucast. Některa temata přinesla konkretni výsledek. Některa nebylo možne jednoznacně uzavřit a budou předmětem dalsich jednani v budoucnu.

BACKGROUND:Assisted reproduction, as well as pregnancy itself, in patients with breast cancer or other hereditary type of cancer, is a widely discussed topic. In the past, patients treated for breast cancer were rarely involved in the discussion about reproductive possibilities or infertility treatment. However, current knowledge suggests, that breast cancer is neither a contraindication to pregnancy, nor to assisted reproduction techniques. On the contrary, assisted reproduction and preimplantation genetic diagnosis methods might prevent the transmission of genetic risks to the fetus.AIM:In this review we summarize data concerning pregnancy risks in patients with increased risk of breast cancer. In addition, we introduce current possibilities and approaches to fertility preservation prior to assisted reproduction treatment as well as novel methods improving the safety of fertility treatment. In the second part of this review, we focus on karyomapping--an advanced molecular genetic tool for elimination of germinal mutations in patients with predisposition to cancer. Moreover, the rapid development of preimplantation genetic diagnosis methods contributes to detection of both chromosomal aneuploidy and causal mutations in a relatively short time-span.

Introduction: During the 25th symposium of assisted reproduction in Brno was lunch time organised as the lunch table discussion on the selected topics of assisted reproduction. More than 150 specialists reviewed themes related to gynecology and embryology.Discussed topics: Lunch table discussion covered the following topics: (1) Cross-border health care in assisted reproduction; (2) Indication for PGS (preimplantation genetic screening) in the context of actual information; (3) Does ovarian stimulation belong to the ambulance of registering gynecologists? (4) Therapy with clomifen - only for IVF specialists? (5) How and with whom should psychological support be directed during IVF? (6) Stimulation in women with low ovarian reserve; (7) Is basic semen analyses sufficient? (8) Time-lapse systems as relevant markers of embryonic development; (9) How to be oriented with choices of media and consumables in the IVF lab, and (10), Freeze All" - is this new trend in cryopreservation suitable for all?Conclusions: Panel conclusions were presented during the afternoon session, which had great attendance, featured lively commentary, and produced some definitive consensus. Certain issues remained inconclusive, and these matters will be the subject of further discussion in the future. Specific summation of all deductions is presented in this paper.

The guidlines are the recommendation for good laboratory practice in embryological laboratories. In this first part the requirements of the clean environment from the point of view of the oocytes, sperm, and embryos protection against infection and from point of view of the embryological laboratory staff health protection were described.

BACKGROUND The swim-up and hyaluronan (HA)-binding methods are used for the selection of good quality spermatozoa to improve pregnancy rates and embryo quality and to reduce the number of miscarriages after IVF. We evaluated whether the processing of sperm by these methods reduces the frequency of spermatozoa with abnormal karyotypes and altered chromatin quality in balanced translocation carriers. METHODS Semen samples of 12 carriers of balanced chromosomal translocations were analysed for the frequency of spermatozoa, which are chromosomally unbalanced due to the segregation of balanced translocations, aneuploidies for chromosomes 7, 8, 13, 18, 21, X or Y, diploid sperm or sperm with fragmented DNA and poorly condensed chromatin. Results obtained by fluorescence in situ hybridization (FISH) and sperm chromatin structure assay were compared between ejaculated (n = 12), swim-up (n = 12) and HA-binding processed (n = 6) semen samples of the translocation carriers and with the control group (n = 10). RESULTS The mean frequencies of unbalanced segregation products were 17.5 and 16.5% in neat and swim-up processed samples from Robertsonian translocation carriers, and 55.4, 54.5 and 50.9% in neat, swim-up and HA-bound sperm samples from reciprocal translocation carriers. Significant decreases in the frequency of sperm showing chromosome 18 and XY disomy and of diploidy, and in the rates of high-density staining sperm were observed in the motile swim-up fractions. There were significantly more sperm showing fragmented chromatin in the group of translocation carriers than in the control group, but no differences in the aneuploidy and diploidy rates were observed. CONCLUSIONS The swim-up method is suitable for selection of sperm with condensed chromatin and a lower frequency of some aneuploidies and of diploidy. The frequency of spermatozoa chromosomally unbalanced due to the segregation of reciprocal (but not Robertsonian) translocations is significantly lower in HA-bound sperm. However, the advantages of either method for selecting normal sperm are limited.

To examine interindividual differences in sperm chromosome aneuploidy, repeated semen specimens were obtained from a group of ten healthy men, aged 20–21 at the start of the study, and analyzed by multi-color fluorescence in situ hybridization (FISH) analysis to determine the frequencies of sperm aneuploidy for chromosomes X, Y, 8, 18 and 21 and of diploidy. Semen samples were obtained three times over a five-year period. Statistical analysis examining the stability of sperm aneuploidy over time by type and chromosome identified two men who consistently exhibited elevated frequencies of sperm aneuploidy (stable variants): one with elevated disomy 18 and one with elevated MII diploidy. Differences among frequencies of aneuploidy by chromosome were also seen. Overall, disomy frequencies were lower for chromosome X, 8 and 18 than for chromosomes 21 or Y and for XY aneuploidy. The frequency of chromosome Y disomy did not differ from XY sperm frequency. Also, the frequency of meiosis I (XY) and II (YY + XX) sex chromosome errors did not differ in haploid sperm, but the frequency of MII errors was lower than MI errors in diploid sperm. Frequencies of sperm aneuploidy were similar between the first sampling period and the second, two years later. However, the frequency of some types of aneuploidy (XY, disomy Y, disomy 8, total autosomal disomies, total diploidy, and subcategories of diploidy) increased significantly between the first sampling period and the last, five years later, while others remained unchanged (disomy X, 21 and 18). These findings confirm inter-chromosome differences in the frequencies of disomy and suggest that some apparently healthy men exhibit consistently elevated frequencies of specific sperm aneuplodies. Furthermore, time/age-related changes in sperm aneuploidy may be detected over as short a period as five years in a repeated-measures study.