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The aim of this study was to determine if the outcomes of aneuploidy and translocation testing by preimplantation genetic diagnosis (PGD) at the 8-cell stage have a predictive value for new genetic diagnosis cycles. In total, 83 cycles (39 patients) undergoing PGD of translocations and 378 cycles (176 patients) of aneuploidy were included. Predictability, defined as having similar rate (±20%) of euploid embryos in the first and successive cycles, was found in 66% of patients undergoing aneuploidy testing. Predictability was found significantly more often in patients undergoing PGD of translocations (90%, P = 0.006). In addition, patients with 0. < 30 or ≥30% euploid embryos in the first cycle were compared and groups 0 and < 30% had significantly fewer euploid embryos in the second cycle (22-26%) than those of the group with ≥30% (37%) (P < 0.05). Patients who did not become pregnant after the first attempt were stimulated more aggressively than those becoming pregnant. producing significantly more embryos in the second than in the first cycle (P < O.001). Therefore, correlation between euploidy rate and pregnancy rate could not be assessed objectively between cycles. In conclusion, the PGD results of a first cycle can predict the results of the second cycle, but this is likely to be of more value when the condition investigated is translocation rather than aneuploidy. The chance of pregnancy is usually related to the number of euploid embryos. [ABSTRACT FROM AUTHOR]

Objective: To achieve a predictive relationship between the proportion of abnormal spermatozoa and the proportion of abnormal embryos from couples in whom the males are translocation carriers. Materials/Methods: Preimplantation genetic diagnosis (PGD) was performed in 11 couples with reciprocal translocation male carriers. Blood sample and sperm sample were collected from each male partner. Embryo biopsy of the embryos was performed in each cycle. Fluorescence in-situ hybridization (FISH) analysis was performed in lymphocyte slides to characterize each translocation case. Specific FISH probes were applied for each of the sperm samples. Results: Sperm results: A total of 11,184 spermatozoa were counted from the 11 patients included in the study. A total of 99 embryos from these 11 cases were biopsied, 93 giving results. Comparison between FISH sperm analysis and PGD results indicated that there was no statistical difference between the segregation types observed in spermatozoa and embryos. A correlation was found between the percentage of abnormal gametes and the percentage of abnormal embryos, and a predictive equation is proposed for this relationship: A = -55 + (1.9 x B). where A is the percentage of abnormal embryos and B the percentage of abnormal spermatozoa. A total of 16 embryos were replaced in 9 of the 11 cases. Four became pregnant, of which three are ongoing and one delivered a healthy normal baby. Conclusions: The predictive value of the sperm analysis is established with a proposed equation. Patients with 65% or less chromosomally abnormal spermatozoa have a good chance at conceiving, whereas patients with higher rates would need to produce 10 or more good-quality embryos to have reasonable chances of conceiving. [ABSTRACT FROM AUTHOR]

Objective: Carriers of balanced translocations or other structural aberration are at risk for reduced fertility, pregnancy losses and delivery of an affected child. This study reports the obstetric outcome of 100 preimplantation genetic diagnosis (PGD) cycles of translocations, inversions and deletions. Materials/Methods: Pregnancy and obstetric outcome information of patients who achieved pregnancy via PGD for chromosomal structural aberrations was gathered via telephone calls with patients and review of a patient information database. Results: One hundred cycles of PGD lot chromosomal structural abnormalities were performed in 72 patients. Thirty cycles resulted in pregnancy, 49 did not, and transfer did not occur in 21. A total of 177 embryos were transferred resulting in 30 pregnancies with 43 fetal heart beats (24.3% implantation). Of these, one pregnancy was terminated because it was found that the fetus had the unbalanced translocation after replacing embryos without result from PGD. Two pregnancy losses occurred, one as a vanishing twin. A reduction from triplets to twins was also performed for obstetric reasons. In total. 39 babies were delivered (19 singletons, seven twins. two triplets). Three of the delivered babies have malformations. One singleton has cleft palate, diaphragmatic hernia and dysmorphism consistent with autosomal dominant lymphoedema-distichiasis syndrome. One of fraternal twins had bilateral renal agenesis. A singleton had tetralogy of Fallot. Conclusions: In the case of lymphoedema-distichiasis syndrome. PGD was performed for a separate condition. deletion 22q11.2. as seen in the mother. The baby inherited lymphoedema-distiehiasis syndrome from the father who is affected. Two babies have new non-familial findings: bilateral renal agenesis and tetralogy of Fallot. The percentage of babies with new malformations (5%. 2/39) is no greater than the 3-5% incidence of congenital malformations in the general population. PGD does not appear to increase the incidence of malformation in offspring. In determination of any association of malformation and the PGD process, one must consider factors such as multiples of pregnancy, non-related new or inherited single gene disorders, chromosomal make-up of the allotted, pregnancy history, study population size and incidence of malformations in a control group of pregnancies or live births. [ABSTRACT FROM AUTHOR]

Objective: One of the most critical steps in preimplantation genetic diagnosis (PGD) studies is the fixation required to obtain good fluorescence in-sire hybridization (FISH) nuclear quality without losing any of the cells analysed. Different fixation techniques have been described. The aim of this study was to compare the results of three fixation methods (i) acetic acid/methanol and modified tot single blastomere fixation: (ii) Tween 20; (iii) Tween 20 and acetic acid/methanol based on the number of cells lost after fixation, the average rate of informative cells, the rate of signal overlaps and the rate of FISH errors. Materials/Methods: Embryos were obtained front patients undergoing IVF at The Institute for Reproductive Medicine and Science at Saint Barnabas Medical Centre (Livingston, NJ) in accordance with guidelines approved by the internal review board. Written patient consent for donated embryo research and for PGD was provided for all embryos. For all three methods the temperature and humidity conditions were the same (22°C and 30-45% respectively), based on previous observations that nuclear diameters are a function of temperature and humidity. FISH analysis was performed using probes for chromosomes X, Y, 13, 15, 16, 17, 18, 21 and 22 following the previously published protocol, except that instead of a locus-specific probe for chromosome 14 we used a cefltrumeric one for chromosome 17, also labelled in Spectrum Orange (Vysis). Results: A total of 100, 106 and 114 blastomeres were fixed using techniques (i), (ii) and (iii) respectively, The present results indicate significant differences in nuclear diameter after fixation, with an average of 58 µm for method (i). 46 µm for method (ii), and 31 µm for method (iii) (P < 0.001) (Table 1). which translates to higher rates of nuclei with signal overlaps (from 14% for method (i) to up to 58% for method (iii). (P < 0.001), total number of overlaps, and FISH errors (from 10% for method (i) to 30% for method (iii), P < 0.005). see Table 1. The correlation between overlaps and FISH errors and small nuclear diameter was also observed irrespective of the type of fixation. For instance, taking all embryos together and grouping them by diameters, those cells with <30 µm in diameter had more overlaps and FISH errors than those cells with >60 µm in diameter (P < 0.005). Conclusions: Technique (ii) gave the worst nuclear quality with higher cytoplasm, number of overlaps and FISH errors, Although technique (i) showed a better nuclear quality in terms of greater nuclear diameter and fewer overlaps and FISH errors, it was difficult to perform correctly. However, technique (iii) showed reasonably good nuclear quality and was easier both to learn and to use for PGD studies than the others. [ABSTRACT FROM AUTHOR]

Objective: To develop a clinically applicable preimplantation genetic diagnosis (PGD) protocol that allows aneuploidy affecting any chromosome to be detected. A methodology was sought that would permit the use of comparative genomic hybridization (CGH) without the need for cryopreservation. Materials/Methods: A 40-year-old patient presenting for IVF treatment underwent ovarian stimulation. Oocytes were collected and the first polar bodies were biopsied from them. Polar body DNA was subjected to whole genome amplification and then used in a CGH experiment. Oocytes were fertilized using intracytoplasmic sperm injection and a single blastomere was biopsied from each of the resulting embryos on day 3 post-fertilization. Blastomeres were subjected to fluorescence in-situ hybridization (FISH) analysis, allowing confirmation of the CGH results. Results: Chromosome imbalance was detected in 9 out of 10 polar bodies tested. A variety of chromosomes were aneuploid, but chromosomal size was found to be an important predisposing factor. In three cases the resulting embryos were available for analysis using FISH and in each case the CGH diagnosis was confirmed. A single embryo could be recommended for transfer on the basis of the CGH data, but no pregnancy ensued on this occasion. Conclusions: Cytogenetic tests have revealed that over 50% of human embryos generated using assisted reproductive technology contain one or more aneuploid cells. There is evidence that such embryos have a reduced developmental potential and their high incidence may explain a significant fraction of failed IVF attempts. The identification and preferential transfer of chromosomally normal embryos to the mother is said to improve IVF outcomes for certain groups of patients. Unfortunately. current PGD methods only allow about one third of the chromosomes to be screened and consequently fail to detect a proportion of abnormal embryos. The first clinical application of a PGD strategy, based on whole genome amplification and CGH analysis of polar bodies, is reported. This allows a full analysis of every chromosome in single cells. The technique was accurate and allowed aneuploid embryos, which would have received a normal diagnosis using standard PGD techniques, to be identified. As well as comprehensive cytogenetic analysis, this protocol also permits simultaneous testing for multiple single-gene disorders. Combined cytogenetic and molecular genetic testing is not feasible using traditional PGD techniques based on FISH and polymerase chain reaction. More development is needed, but it is hoped that methods such as these could ultimately improve IVF success rates further. [ABSTRACT FROM AUTHOR]

Preimplantation genetic diagnosis (PGD) for gender selection for non-medical reasons has been considered an unethical procedure by several authors and agencies in the Western society on the basis that it could disrupt the sex ratio, that it discriminates against women and that it leads to disposal of normal embryos of the non-desired gender. In this study, the analysis of a large series of PGD procedures for gender selection from a wide geographical area in the USA shows that, in general, there is no deviation in preference towards any specific gender except for a preference of males in some ethnic populations of Chinese, Indian and Middle Eastern origin that represent a small percentage of the US population. In cases where only normal embryos of the non-desired gender are available, 45.5% of the couples elect to cancel the transfer, while 54.5% of them are open to have embryos transferred of the non-desired gender, this fact being strongly linked to cultural and ethnic background of the parents. In addition this study adds some evidence to the proposition that, in couples with previous children of a given gender, there is no biological predisposition towards producing embryos of that same gender. Based on these facts, it seems that objections to gender selection formulated by ethics committees and scientific societies are not well founded. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated mosaicism in a large series of cleavage-stage human embryos analysed by fluorescence insitu hybridization. Materials/Methods: Only embryos with at least three cells analysed were included (n = 1235) of which 556 were mosaics. These embryos were all analysed al least with probes for chromosomes XY, 13, 15, 16, 18, 21, 22 and either 1 or 17. Results: The most common types of mosaicism were chaotic (48%), diploid/polyploid (26%), and those caused by mitotic non-disjunction (25%). The number of abnormal cells per embryo ranged from 44% in diploid/polyploid to 84% in chaotic mosaics. Chromosome 16 was most commonly involved in mitotic non-disjunction mosaics. Although overall mosaicism did not increase with maternal age, the average maternal age of the embryos that had mosaics caused by mitotic non-disjunction was significantly higher than that for normal or other mosaic embryos (P < 0.1001). Conclusions: During cleavage-stage, the embryonic genome is not yet fully activated and consequently the mRNA and protein pools are still similar to those found in the oocyte. It is therefore proposed that the malfunctioning of the meiosis apparatus, which is similar to the mitotic one. may either cause meiotic errors or mitotic non-disjunction at cleavage-stage embryo development. [ABSTRACT FROM AUTHOR]

Embryo chromosome studies show high rates of abnormalities, above 50%, but most embryos studied were from patients aged 35 and older. The objectives of this study were firstly, to evaluate the rate of chromosome abnormalities in embryos from young egg donors, and secondly, to compare the range of chromosome abnormality rates between donors and non-egg donor cycles, both undergoing preimplantation genetic diagnosis (PGD) for infertility using fluorescence in-situ hybridization analysis with probes for chromosomes X, Y, 13, 15, 16, 18, 21, and 22. On average, only 43% of the embryos were chromosomally normal, while the comparison group had euploidy rates between 34 (age group 18-34) (P < 0.001) and 21% (age group 40-45) (P < 0.001). There was considerable variation between donor cycles, with almost one-third having less than 30% normal embryos. Also, within donors and recipients repeating several IVF cycles with PGD, only 29-56% of the second PGD cycles had similar rates of normal embryos to the first cycle, while in the comparison group it was 64%. The results can explain why some egg donors are successful whereas others are not, and may also show that a policy of PGD for first time egg donors is appropriate and indicated. [ABSTRACT FROM AUTHOR]