Inter-laboratory agreement on embryo classification and clinical decision: Conventional morphological assessment vs. time lapse.

The aim of this study is to determine inter-laboratory variability on embryo assessment using time-lapse platform and conventional morphological assessment. This study compares the data obtained from a pilot study of external quality control (EQC) of time lapse, performed in 2014, with the classical EQC of the Spanish Society for the Study of Reproductive Biology (ASEBIR) performed in 2013 and 2014. In total, 24 laboratories (8 using EmbryoScope™, 15 using Primo Vision™ and one with both platforms) took part in the pilot study. The clinics that used EmbryoScope™ analysed 31 embryos and those using Primo Vision™ analysed 35. The classical EQC was implemented by 39 clinics, based on an analysis of 25 embryos per year. Both groups were required to evaluate various qualitative morphological variables (cell fragmentation, the presence of vacuoles, blastomere asymmetry and multinucleation), to classify the embryos in accordance with ASEBIR criteria and to stipulate the clinical decision taken. In the EQC time-lapse pilot study, the groups were asked to determine, as well as the above characteristics, the embryo development times, the number, opposition and size of pronuclei, the direct division of 1 into 3 cells and/or of 3 into 5 cells and false divisions. The degree of agreement was determined by calculating the intra-class correlation coefficients and the coefficient of variation for the quantitative variables and the Gwet index for the qualitative variables. For both EmbryoScope™ and Primo Vision™, two periods of greater inter-laboratory variability were observed in the times of embryo development events. One peak of variability was recorded among the laboratories addressing the first embryo events (extrusion of the second polar body and the appearance of pronuclei); the second peak took place between the times corresponding to the 8-cell and morula stages. In most of the qualitative variables analysed regarding embryo development, there was almost-perfect inter-laboratory agreement among conventional morphological assessment (CMA), EmbryoScope™ and Primo Vision™, except for false divisions, vacuoles and asymmetry (users of all methods) and multinucleation (users of Primo Vision™), where the degree of agreement was lower. The inter-laboratory agreement on embryo classification according to the ASEBIR criteria was moderate-substantial (Gwet 0.41-0.80) for the laboratories using CMA and EmbryoScope™, and fair-moderate (Gwet 0.21-0.60) for those using Primo Vision™. The inter-laboratory agreement for clinical decision was moderate (Gwet 0.41-0.60) on day 5 for CMA users and almost perfect (Gwet 0.81-1) for time-lapse users. In conclusion, time-lapse technology does not improve inter-laboratory agreement on embryo classification or the analysis of each morphological variable. Moreover, depending on the time-lapse platform used, inter-laboratory agreement may be lower than that obtained by CMA. However, inter-laboratory agreement on clinical decisions is improved with the use of time lapse, regardless of the platform used.

Elective single-embryo transfer in oocyte donation programmes: Should it be the rule?

The aim of this study is to compare the cumulative clinical pregnancy and live birth rates (fresh embryo transfers followed by frozen-thawed embryo transfers from the same stimulated cycle) between single-embryo transfer (SET) and double-embryo transfer (DET) in an oocyte donation programme. A retrospective analysis of the outcome in 1139 recipient fresh cycles (1073 from DET and 66 from SET) with at least three available embryos for transfer was performed. The clinical pregnancy rates were similar after SET (45.5%, 30/66) and DET (57.1%, 613/1073), whereas the multiple pregnancy rate was 0% and 39.5% for SET and DET, respectively. After evaluating the results using the Kaplan-Meier survival analysis in a period of 1 year, no statistically significant differences were observed in the cumulative clinical pregnancy and live birth rates (SET 82.8% and 76.4% versus DET 77.2% and 63.7%). The results indicate that for women who have at least three available embryos in oocyte donation programmes, one single embryo should be transferred as no significant decrease in the success rate is observed and multiple pregnancy can be avoided. Clinical pregnancy rate is higher when transferring two embryos compared with one. However, this also results in a higher incidence of twin pregnancy, which is associated with increased obstetric and perinatal risks. The aim of this study was to compare the cumulative clinical pregnancy and live birth rates (fresh embryo transfers followed by frozen-thawed embryo transfers from the same stimulated cycle) between single-embryo transfer (SET) and double-embryo transfer (DET) cycles in our oocyte donation programme. A retrospective analysis of the outcome in 1139 recipient fresh cycles (1076 from DET and 66 from SET) with at least three available embryos for transfer was performed. The clinical pregnancy rates were similar after SET (45.5%, 30/66) and DET (57.1%, 613/1073), whereas the multiple pregnancy rate was 0% and 39.5% for SET and DET, respectively. The cumulative clinical pregnancy and live birth rates were similar between the two strategies (SET 82.8% versus DET 77.2%) and the same was found for the cumulative live birth rates (SET 76.4% versus DET 63.7%). Our results indicate that for women who have at least three available embryos in OD programmes, one single embryo should be transferred as no significant decrease in the success rate is observed while multiple pregnancy is avoided.

Conceptos de nutrición enteral en geriatría (II) / No disponible

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Nutrición enteral en Geriatría / No disponible

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Correlation between embryological factors and pregnancy rate: development of an embryo score in a cryopreservation programme.

PURPOSE: To establish which embryo parameters, in frozen thawed embryo transfers, have the highest prognosis value in the establishment of pregnancy. The relative importance of different embryo parameters is used to develop an embryo score. METHODS: Retrospective analysis of the implantation rate in 356 frozen/thawed single embryo transfers. A logistic regression model is used to establish an embryo score. RESULTS: A direct correlation is established between the implantation rate and fresh embryo development (number of blastomeres and their symmetry), survival rate after thawing and mitosis resumption after overnight culture. CONCLUSIONS: An embryo score is developed to determine the implantation potential of frozen/thawed embryos.

Analysis of factors associated with multiple pregnancy in an oocyte donation programme.

The aim of this study is to identify the factors associated with multiple pregnancy in an oocyte donation programme. A retrospective study (2000-2007) of 945 synchronous cycles was performed. Two embryos were transferred in all cycles on day 2 after oocyte retrieval. All variables (egg donor and recipient age, number of inseminated oocytes, fertilized oocytes, cleaved embryos, good-quality embryos available, good-quality embryos transferred and frozen embryos) were analysed in relation to the clinical pregnancy rate per transfer (PR) and the multiple pregnancy rate (MPR). The donor age was 26.8±4.5 years and recipient age was 41.0±5.4. The number of good-quality embryos per recipient was 3.1±2.5. The PR was 55.1% and the MPR 36.5%. The number of good-quality embryos transferred (2 versus 0) was significantly associated (P<0.05) with the PR (60.6% versus 43.5%). The relationship between the MPR and the number of good-quality embryos transferred was adjusted by donor and recipient's age. For those patients who received 2 versus 0 good-quality embryos, the odds ratio of a multiple pregnancy was 2.1 (95% CI 1.121-3.876). The only predictive factor for multiple pregnancies in an oocyte donation programme is the quality of the transferred embryos. Since the development of assisted reproduction techniques, most countries have witnessed increased rates of multiple pregnancy. In IVF/intracytoplasmic sperm injection, effective strategies must be established to prevent multiple pregnancy without reducing overall pregnancy rates. In oocyte donation programmes, there is less awareness about the related risks. Actually, a minimum of two embryos are still transferred in most centres. The patient's age is higher and this fact implies more obstetric and perinatal complications. The aim of this study is to identify the factors associated with multiple pregnancy to contribute to establish future guidelines to avoid those risks.

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 Tesarik's and Scott's 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.