Sperm chromosomal abnormalities and their contribution to human embryo aneuploidy.

In this work we reviewed 18 years of experience using fluorescence in situ hybridization (FISH) for sperm aneuploidy testing. We evaluated parameters associated with increased numerical sperm chromosome abnormalities and determined the male contribution to embryo aneploidies in terms of reproductive outcome by increased sperm aneuploidy. This retrospective study analyzed data from 2008 sperm samples of infertile males undergoing FISH analysis because of clinical history of repetitive implantation failure, recurrent miscarriage, impaired sperm parameters, or mixed causes. Sperm concentration was the only sperm parameter associated with FISH results-we observed a gradual increase of abnormal sperm FISH results in males with decreasing sperm concentration. However, a great proportion of normozoospermic males also showed increased sperm aneuploidies, suggesting that sperm parameters alone do not enable identification of a substantial proportion of infertile males at risk of sperm aneuploidies. Regarding reproductive outcomes, couples with normal sperm FISH results for the male had similar outcomes regardless of conventional in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), or preimplantation genetic testing for aneuploidies (PGT-A). However, couples with abnormal sperm FISH results for the male showed better clinical outcomes after PGT-A, suggesting a potential contribution of sperm to embryo aneuploidy. Moreover, PGT-A cycles showed better clinical outcomes when 24 chromosomes were analyzed by array comparative genome hybridization (aCGH) or next-generation sequencing (NGS) instead of only nine chromosomes analyzed by FISH. In conclusion, sperm FISH analysis offers clinical prognostic value to evaluate reproductive possibilities in infertile couples. Therefore, couples with abnormal sperm FISH results should be offered genetic counseling and presented with clinical options such as PGT-A.

Fetal sex determination in twin pregnancies using cell free fetal DNA analysis.

OBJECTIVE(S): We sought to develop an accurate sex classification method in twin pregnancies using data obtained from a standard commercial non-invasive prenatal test. STUDY DESIGN: A total of 706 twin pregnancies were included in this retrospective analytical data study. Normalized chromosome values for chromosomes X and Y were used and adapted into a sex-score to predict fetal sex in each fetus, and results were compared with the clinical outcome at birth. RESULTS: Outcome information at birth for sex chromosomes was available for 232 twin pregnancies. From these, a total of 173 twin pregnancies with a Y chromosome identified in non-invasive pregnancy testing were used for the development of a predictive model. Global accuracy for sex classification in the testing set with 51 samples was 0.98 (95% confidence interval [0.90,0.99]), with a specificity and sensitivity of 1 (95% confidence interval [0.82,1.00]) and 0.97 (95% confidence interval [0.84,0.99]), respectively. CONCLUSION: While non-invasive prenatal testing is a screening method and confirmatory results must be obtained by ultrasound or genetic diagnosis, the sex-score determination presented herein offers an accurate and useful approach to characterizing fetus sex in twin pregnancies in a non-invasive manner early on in pregnancy.

Corrigendum to "A Higher Ovarian Response after Stimulation for IVF Is Related to a Higher Number of Euploid Embryos".

[This corrects the article DOI: 10.1155/2017/5637923.].

A Higher Ovarian Response after Stimulation for IVF Is Related to a Higher Number of Euploid Embryos.

This study has analysed the relationship between ovarian response and the number of euploid embryos. This is a post hoc analysis of a subset of data generated during a prospective cohort study previously published. Forty-six oocyte donors were subjected to ovarian stimulation with 150 IU of rFSH and 75 IU of hp-hMG in a GnRH agonist long protocol. Preimplantation genetic screening was performed in all viable embryos. We observed a positive relationship between ovarian response and the number of euploid embryos. When ovarian response was above the median (≥17 oocytes), the mean number of euploid embryos per donor was 5.0 ± 2.4, while when <17 oocytes were obtained the mean number of euploid embryos was 2.7 ± 1.4 (p = 0.000). Aneuploidy rate did not increase with ovarian response or gonadotropin doses. Also, the number of euploid embryos was inversely related to the amount of gonadotropins needed per oocyte obtained (ovarian sensitivity index). These results suggest that the number of euploid embryos available for embryo transfer increases as the number of oocytes obtained does. Considering the total number of euploid embryos seems more relevant than the aneuploidy rate.

Distribution patterns of segmental aneuploidies in human blastocysts identified by next-generation sequencing.

OBJECTIVE: To evaluate the ability of next-generation sequencing (NGS) to detect pure and mosaic segmental aneuploidies in trophectoderm biopsies and to identify distribution patterns in whole blastocysts. DESIGN: Validation study. SETTING: Reference laboratory. PATIENT(S): Seventy couples with known karyotypes who had undergone preimplantation genetic screening with diagnoses at the blastocyst stage using array comparative genomic hybridization (aCGH). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Concordance rates for segmental and whole-chromosome aneuploidies determined between aCGH and NGS, and estimates of mosaicism levels of segmental aneuploidies in fixed blastocysts. RESULT(S): We used NGS with amplified DNA from trophectoderm biopsies in which segmental aneuploidies had been previously detected by array comparative genomic hybridization (aCGH). Single-cell fluorescent in situ hybridization (FISH) was then used as an independent form of analysis. The concordance rate between NGS and aCGH was 124 (98.4%) of 126 for the detection of segmental aneuploidies, and 48 (96.0%) of 50 for whole-chromosome aneuploidies. The overall concordance rate was 99.8% (2,276 of 2,280 chromosomes assessed). After FISH analyses with 41.4 ± 24.3 cells per blastocyst, 26 (92.9%) of 28 segmentals detected by aCGH and NGS were confirmed. The FISH analysis did not detect the segmentals in two blastocysts, in which all cells analyzed were euploid. CONCLUSION(S): This is the first report analyzing distribution patterns of segmental aneuploidies in trophectoderm biopsy by NGS. We have demonstrated that NGS allows the detection of pure and mosaic segmental aneuploidies with the same efficiency as aCGH. The FISH analysis confirmed the existence of these events in the trophectoderm and the inner cell mass.

New tools for embryo selection: comprehensive chromosome screening by array comparative genomic hybridization.

The objective of this study was to evaluate the usefulness of comprehensive chromosome screening (CCS) using array comparative genomic hybridization (aCGH). The study included 1420 CCS cycles for recurrent miscarriage (n = 203); repetitive implantation failure (n = 188); severe male factor (n = 116); previous trisomic pregnancy (n = 33); and advanced maternal age (n = 880). CCS was performed in cycles with fresh oocytes and embryos (n = 774); mixed cycles with fresh and vitrified oocytes (n = 320); mixed cycles with fresh and vitrified day-2 embryos (n = 235); and mixed cycles with fresh and vitrified day-3 embryos (n = 91). Day-3 embryo biopsy was performed and analyzed by aCGH followed by day-5 embryo transfer. Consistent implantation (range: 40.5-54.2%) and pregnancy rates per transfer (range: 46.0-62.9%) were obtained for all the indications and independently of the origin of the oocytes or embryos. However, a lower delivery rate per cycle was achieved in women aged over 40 years (18.1%) due to the higher percentage of aneuploid embryos (85.3%) and lower number of cycles with at least one euploid embryo available per transfer (40.3%). We concluded that aneuploidy is one of the major factors which affect embryo implantation.

Use of array comparative genomic hybridization (array-CGH) for embryo assessment: clinical results.

OBJECTIVE: To review clinical outcomes after preimplantation genetic screening. Most methods of embryo viability assessment involve morphologic evaluation at different preimplantation developmental stages. A weak association between blastocyst morphology and aneuploidy has been described, supporting the basis for preimplantation genetic screening (PGS) for assessment of embryo viability. The expected improvement in reproductive outcome rates has been reached with the application of microarrays based on comparative genomic hybridization (CGH) in clinical routine PGS. DESIGN: Review of published studies and own unpublished data. SETTING: University-affiliated private institution. PATIENT(S): IVF patients undergoing PGS at different stages. INTERVENTION(S): PGS with polar body, cleavage-stage, and blastocyst biopsies. MAIN OUTCOME MEASURE(S): Aneuploidy, implantation, and pregnancy rates. RESULTS: The clinical outcome after analysis of all 24 chromosomes improved pregnancy and implantation rates for different indications to a higher degree than the previously available technology, fluorescence in situ hybridization (FISH), in which only a limited number of chromosomes could be analyzed. CONCLUSION(S): Most of the data regarding the controversy of day-3 biopsy come from FISH cycles, and the utility of day-3 biopsy with new array-CGH technology should be further evaluated through randomized controlled trials. The current trend is blastocyst biopsy with a fresh transfer or vitrification for transfer in a nonstimulated cycle.

False positive rate of an arrayCGH platform for single-cell preimplantation genetic screening and subsequent clinical application on day-3.

In this work, false positive rate of an arrayCGH platform for its use in day-3 single-blastomere analysis was calculated. For this purpose, 38 embryos diagnosed as abnormal on day-3 by FISH were re-biopsied on day-4. Single-cell day-4 arrayCGH diagnosis was then performed. A successful amplification was obtained in 97.4 % (37/38) of the day-4 cells analysed by arrayCGH. Day-3 FISH and day-4 arrayCGH diagnosis were concordant in 35/37 cases. The two discordant embryos were spread and all the cells from each embryo were re-analysed by FISH on day 5. The same error rate (2.7 %) for day-3 FISH and day-4 arrayCGH was obtained when comparing day-5 FISH re-analysis. After this pre-clinical phase, the platform was used for day-3 arrayCGH clinical application in 320 patients (1,760 embryos). Day-3 amplification rate was 98.6 %. An optimal reproductive outcome was obtained when applying arrayCGH to a clinical program: clinical pregnancy rate per cycle of 38.4 % and 60.3 % per transference were obtained, with an implantation rate of 53.5 %. Overall miscarriage rate was 10.6 %. Additionally, day-5 FISH re-analysis was performed in 42 of the embryos from the clinical phase, obtaining a concordance rate of 97.6 % with day-3 arrayCGH.

Redefining advanced maternal age as an indication for preimplantation genetic screening.

In this retrospective study, the utility of preimplantation genetic screening (PGS) in patients with advanced maternal age is evaluated. The patient population consisted of women aged 38-44years and included in a regular IVF programme with or without PGS analysis. Transfer rate, ongoing implantation rate and ongoing pregnancy rate were the main outcome parameters measured. A trend of better ongoing pregnancy rate per oocyte retrieval was observed in patients aged 38 and 39years in the non-PGS group when compared with PGS groups, but better ongoing pregnancy rate per oocyte retrieval was observed in patients 41-44years old in the PGS group. When patients with a low ovarian response accumulated oocytes in several stimulation cycles, clinical outcomes were comparable to those of normal-responder patients. These results show that, although PGS does not benefit patients less than 40years of age, reproductive success increases more than two-fold in patients over 40years, especially in patients with more than six metaphase II oocytes, as a result of a good ovarian response or gamete accumulation, suggesting a redefinition of advanced maternal age as indication for PGS. In this retrospective study, the utility of preimplantation genetic screening (PGS) in patients with advanced maternal age is evaluated. Patient population consisted of women aged 38-44 years and included in a regular IVF programme with or without PGS analysis. Transfer rate, ongoing implantation rate and ongoing pregnancy rate were the main outcome parameters measured. A trend of better ongoing pregnancy rate per ovarian stimulation cycle was observed in patients aged 38-39 years in the non-PGS group when compared with PGS groups, but better ongoing implantation rate was observed in patients aged 41-44 years old in the PGS group. When patients with a low ovarian response (low number of oocytes available for the IVF cycle) accumulated oocytes in several stimulation cycles, their reproductive possibilities were comparable to those of normal-responder patients. These results show that, although PGS does not benefit patients less than 40 years of age, reproductive success increases more than 2-fold in patients over 40 years, especially in patients with more than six metaphase II oocytes, as a result of a good ovarian response or gamete accumulation, suggesting a redefinition of advanced maternal age as indication for PGS.

Aneuploidies in embryos and spermatozoa from patients with Y chromosome microdeletions.

In patients with Y chromosome microdeletions and high percentage of numeric chromosome abnormalities detected by fluorescence in situ hybridization on sperm, a high percentage of abnormal embryos was observed compared with oligozoospermic patients without Y chromosome microdeletions, with a significant increase in the percentage of embryos with monosomy X. Differences in fertilization rates between the different patient groups were not observed; however, blastocyst rates were significantly impaired in patients with Y chromosome microdeletions.

Impact of different patterns of sperm chromosomal abnormalities on the chromosomal constitution of preimplantation embryos.

OBJECTIVE: To evaluate the effect of sperm chromosome abnormalities--disomy for sex chromosomes and diploidy--in the chromosomal constitution of preimplantation embryos. DESIGN: Retrospective cohort study. SETTING: Infertility clinic. PATIENT(S): Three groups: 46,XY infertile men with increased incidence of sex chromosome disomy in sperm; 46,XY infertile men with increased diploidy rates in sperm; 47,XYY infertile men with increased sex chromosome disomy and diploidy rates in sperm. INTERVENTION(S): Sperm collection for fluorescence in situ hybridization analysis. Embryo biopsy for preimplantation genetic screening. MAIN OUTCOME MEASURE(S): Frequencies of numerical abnormalities in sperm for chromosomes 13, 18, 21, X, and Y, and in embryos for chromosomes 13, 16, 18, 21, 22, X, and Y. RESULT(S): A significant increase of chromosomally abnormal and mosaic embryos was observed in the three study groups compared with controls. Those sperm samples with increased sex chromosome disomy rates produced significantly higher percentages of aneuploid embryos, with a threefold increase for sex chromosomes. Sperm samples with increased diploidy rates were mainly associated to the production of triploid embryos. CONCLUSION(S): A strong correlation between sperm and embryo chromosomal constitution has been shown in infertile men with 46,XY and 47,XYY karyotypes.

Prognostic factors for preimplantation genetic screening in repeated pregnancy loss.

The objective of this study was to identify specific subgroups of recurrent pregnancy loss (RPL) patients of unknown aetiology in whom the selection of chromosomally normal embryos for transfer improves reproductive outcome in preimplantation genetic screening (PGS). A total of 428 PGS cycles were included and chromosomes 13, 15, 16, 18, 21, 22, X and Y were evaluated. In RPL patients < or =37 years, a lower incidence of chromosomal abnormalities (P = 0.0004) and miscarriages (P = 0.0283) was observed, and there were significantly higher pregnancy (P < 0.0384) and implantation (P < 0.0434) rates than in patients >37 years. In the former subset, results showed: (i) significantly higher implantation rates (P = 0.0411) in couples that had experienced a previous aneuploid miscarriage; (ii) similar aneuploidy, pregnancy and implantation rates in couples suffering previous miscarriages during fertility treatments and in those with previous spontaneous pregnancies; (iii) no miscarriages after PGS in couples in whom a fluorescence in-situ hybridization assay showed the male partner's sperm to be abnormal; and (iv) lower implantation rates in couples with > or =5 previous miscarriages, associated with a lower percentage of chromosomally abnormal embryos. It is concluded that PGS is to be strongly recommended when RPL is associated with miscarriages during infertility treatments, chromosomopathy in a previous miscarriage, up to five previous miscarriages and a high incidence of chromosomal abnormalities in spermatozoa.

Impact of chromosomal abnormalities on preimplantation embryo development.

OBJECTIVES: To evaluate the influence of numerical chromosomal abnormalities on preimplantation embryo development. METHODS: This study includes 6936 embryos from 1245 women undergoing preimplantation genetic diagnosis (PGD). Indications for aneuploidy screening were: recurrent miscarriages, implantation failure, severe male factor, advanced maternal age, and mixed causes. Embryo biopsy was performed on day 3, and embryos were co-cultured until day 5, when embryo transfer was performed. RESULTS: In the aneuploidy screening regimen, normal euploid embryos showed significantly higher blastocyst rates (68.2%) compared to chromosomally abnormal (42.8%, p < 0.0001) and mosaic (53.7%, p < 0.0001) embryos. Among aneuploid embryos for autosomes, higher blastocyst rates were observed in trisomies than monosomies, although only statistically significant in patients over 36 years of age (50.8 vs 38.9%; p < 0.0001). In contrast, in embryos with sex chromosomes aneuploidy, similar blastocyst rates were observed between trisomies and monosomy X. CONCLUSION: Embryos with certain types of chromosomal abnormalities were negatively selected during preimplantation embryo development. Despite this selection, a remarkable percentage of chromosomally abnormal embryos can develop normally to blastocyst stage with high probability of implantation and pregnancy.

FISH screening of aneuploidies in preimplantation embryos to improve IVF outcome.

Preimplantation genetic diagnosis (PGD) has transformed the approach to the infertility patient in the IVF setting. Although the principal applications of PGD have been to prevent the transmission of sex-linked diseases, in time and with growing knowledge of the chromosomal abnormalities observed in preimplantation embryos, its applications have widened. Nowadays, apart from its implications in the prevention of transmission of chromosomal and genetic abnormalities, PGD is being used with increased frequency to improve the IVF outcome in patients with advanced maternal age (> or =38 years of age), recurrent miscarriage (> or =2 miscarriages), recurrent IVF failure (> or =3 failed IVF attempts) and severe male infertility. A high incidence of chromosomal abnormalities has been observed in these patient groups.

Selective generation of different dendritic cell precursors from CD34+ cells by interleukin-6 and interleukin-3.

There is a growing interest in generating dendritic cells (DCs) for using as vaccines. Several cytokines, especially stem cell factor (SCF) and FLT3-ligand (FL), have been identified as essential to produce large numbers of myeloid precursors and even to increase DC yield obtained by the action of granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha). However, there are few studies on the effect of the early-acting cytokines, commonly used to expand CD34+ progenitor cells, on DC generation. We report here that in the absence of serum, SCF, FL, and thrombopoietin (TPO) plus interleukin-6 (IL-6) and SCF, FL, and TPO plus IL-3 were able to generate CD14+CD1a- and CD14- CD1a+ myeloid DC precursors from CD34+ cells, but IL-6 had an inhibitory effect on the generation of CD14- CD1a+ cells. Both DC precursors differentiated into mature DCs by GM-CSF, IL-4, and TNF-alpha, and DCs obtained from both types of culture exhibited equal allostimulatory capacity. CD1a+ DCs generated could be identified on the basis of DC-specific intracellular adhesion molecule-grabbing nonintegrin (DC-SIGN) expression, a novel C-type lectin receptor expressed on dermal DCs but not on Langerhans cells. In addition, the inclusion of IL-3 to the culture medium induced the appearance of CD13- cells that differentiated into plasmacytoid DC (DC2) on the addition of TNF-alpha, allowing the identification of developmental stages of DC2. Like true plasmacytoid DCs, these cells secreted interferon-alpha after TLR9-specific stimulation with a specific CpG nucleotide.

CD34+CD38- is a good predictive marker of cloning ability and expansion potential of CD34+ cord blood cells.

BACKGROUND: Ex vivo expansion of HPCs is an attractive approach to overcoming the current limitations of human cord blood transplantation. It is important not only to define the optimal culture conditions but also to know the number of progenitor cells that can be obtained. CD34+ cells have a great variability in their cloning capacity and in their ability to expand HPCs. This study was carried out to assess whether this variability could be due to intrinsic or extrinsic factors. STUDY DESIGN AND METHODS: CD34+ cells were analyzed for the expression of CD38, CD133, and CD117 and cultured in serum-free culture medium with four cytokine combinations: SCF plus thrombopoietin plus flt3 ligand (STF), STF plus IL-3, STF plus IL-6, and STF plus IL-6 plus IL-3. After a 1-week culture, the numbers of CD34+ cells and CFUs were determined. RESULTS: The variability observed both in the cloning ability of CD34+ isolated cells and in their expansion capacity was inversely related to the frequency of the more immature CD34+CD38- cells. When more mature CD34+CD38+ cells were present within CD34+-isolated cells, a higher cloning ability, measured as CFUs, and a higher expansion capacity were observed. CONCLUSION: Enumeration of CD34+CD38- cells is correlated with the number of committed progenitors and the capacity of generating CD34+ cells, an important parameter if expansion protocols must be used in clinical transplantation.

IL-6 precludes the differentiation induced by IL-3 on expansion of CD34+ cells from cord blood.

BACKGROUND AND OBJECTIVES: Ex vivo expansion of hematopoietic progenitor cells (HPC) from umbilical cord blood (UCB) is an interesting strategy to obtain a sufficient number of transplantable cells for adults. To define the optimal culture conditions allowing the generation of HPC that retain their proliferative capacity without loss of long-term culture-initiating cells (LTC-IC), the effect of different cytokine combinations on the expansion of CD34+ cells from UCB was assessed. DESIGN AND METHODS: CD34+ cells were cultured in serum-free culture medium with four cytokine combinations: stem cell factor plus thrombopoietin plus flk2/flt3 ligand (STF), STF plus interleukin-3 (IL-3), STF plus interleukin-6 (IL-6) and STF plus IL-6 plus IL-3. After a 1-week culture, the number of CD34+ and CD133+ cells, colony forming units (CFU), LTC-IC and telomerase activity were determined. RESULTS: The addition of IL-6 or IL-3 to the combination of STF significantly enhanced the expansion of CD34+, CD133+ cells and CFU. All cytokine combinations tested induced a slight increase in LTC-IC number except that composed by STF plus IL-3. The greatest induction of telomerase activity was observed with the combination of STF plus IL-3 or plus IL-3 plus IL-6. Decay of the activity along time was observed when the combination of STF plus IL-3 was used, and this effect was reverted by the addition of IL-6. INTERPRETATION AND CONCLUSIONS: Our results demonstrate that the inclusion of IL-6 in a serum-free short-term culture has a beneficial effect on HPC expansion from UCB, and precludes the negative effects induced by IL-3 on LTC-IC expansion and telomerase activity.