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Study Question: Does BCAR4 have a role in mammalian embryo development?, Summary Answer: Expression, localization and functional data support that BCAR4 is a maternal-effect protein in non-rodent mammals., What Is Known Already: BCAR4 was previously identified as an oocyte-specific gene in cattle, and as a marker of certain breast tumors in humans., Study Design, Size, Duration: Human oocytes were obtained from patients undergoing IVF, but had failed to mature after ovarian stimulation. Dog oocytes were obtained from ovariectomized bitches. Pig, horse and bovine ovaries were obtained from commercial slaughterhouses for extraction of immature oocyte-cumulus complexes. In vivo matured bovine matured oocytes were obtained after ovulation induction and ovulation inducing treatment of Montbeliard heifers., Materials, Setting and Methods: Expression at the RNA level was analyzed by reverse transcription coupled to polymerase chain reaction. Western blot and immunolabeling coupled to confocal or electronic microscopy were used to analyze bovine protein expression and intracellular localization. For the functional approach, short-interfering RNA were microinjected into mature bovine oocytes, followed by IVF; cleavage and embryo development were recorded., Main Results and the Role of Chance: The BCAR4 gene is conserved in mammalian species from various orders and has been lost in rodents after divergence with lagomorphs. The transcript is expressed in the oocytes of humans and domestic species. We bring the first experimental evidence of the BCAR4 protein in mammals. In cattle, the protein is not detected in immature oocytes but starts to be synthesized during maturation, increases in the zygote and persists until the morula stage. The protein is detected throughout the cytoplasm in mature oocytes, concentrates in and around the pronuclei in the zygote, and appears to shuttle in and out of the nuclei starting in the 2-cell embryo; BCAR4 is also present at the junctions between blastomeres from 2-cell to morula. In our functional approach, targeting the BCAR4 transcript by small-interfering RNA significantly compromised development to the morula or/and blastocyst stages (P < 0.05, logistic regression)., Limitations, Reasons for Caution: As indicated above, protein expression and function were investigated in cattle and mostly in vitro matured oocytes were used., Wider Implications of the Findings: This study provides a novel candidate gene whose mutation or deregulation may underlie certain cases of unexplained female infertility.

BACKGROUND Embryologists currently face a challenge when counselling patients regarding the stage and the number of embryos to transfer when no top-quality embryos (TQE) are available. METHODS The aim of this study was to evaluate the efficacy of single blastocyst transfer (SBT) in comparison with the transfer of two cleavage-stage embryos in women under 36 years old. A total of 450 women under 36 years undergoing their first or second IVF treatment who had no TQE on Day 2 were included in this prospective study. Couples were assigned to either a SBT or a double cleavage-stage embryo transfer (DET). The clinical end-points monitored were rates of implantation, delivery and multiple deliveries. RESULTS The rate of transfer was significantly lower for couples assigned to the SBT group compared with the DET group (88 versus 100%, respectively, P < 0.001) while the delivery rate per oocyte retrieval was similar in both groups (26.7%). By contrast, the rate of multiple deliveries was significantly lower in the SBT group compared with the DET group (3.3 versus 23.3%, respectively, P < 0.01). Blastocyst cryopreservation was twice as high in the SBT group compared with the DET group (39 versus 18%, respectively, P < 0.001). CONCLUSIONS These findings show the value of extended embryo culture for couples without TQE. In such situations, delaying embryo transfer in order to select a single blastocyst with the highest potential for implantation can reduce the number of multiple pregnancies. Furthermore, our results demonstrate that extended culture allows blastocyst cryopreservation from embryos not available for Day 2 cryopreservation.

Background: Whether extended culture allowing selection of embryos with high development potential has any advantage over cleavage-stage embryo transfer remains a matter of debate. Among the currently unsolved questions, the cumulative delivery rate resulting from fresh and frozen embryo transfers needs to be taken into account in both strategies. The aim of our study was, therefore, to compare the efficacy of single embryo transfer either on Day 2 or on Day 5/6 combining fresh and frozen embryo transfers., Methods: A prospective study including 478 couples assigned on a voluntary basis to undergo elective single embryo transfer (eSET, n = 243) on Day 2 or single blastocyst transfer (SBT, n = 235) on Day 5/6 was performed. The primary outcome measurement was the cumulative delivery rate including fresh and frozen-thawed cycles in both groups., Results: The delivery rate per cycle following fresh embryo transfer was significantly higher in the SBT group compared with the eSET group (P < 0.01). Conversely, frozen embryo and/or blastocyst transfers tended to result in a higher number of deliveries in the eSET compared with the SBT group. Altogether, the cumulative delivery rate per couple, including fresh and frozen embryo transfers, was similar between the two groups (37.9% versus 34.2% in the SBT and eSET groups, respectively)., Conclusions: The observed cumulative delivery rates in this study do not allow us to take a position in favor of SBT or eSET. An improvement in blastocyst cryopreservation may change this attitude.

The 'ESHRE Guidelines for Good Practice in IVF Laboratories' were drawn up by the Special Interest Group (SIG) in Embryology and published in the year 2000, and since then they constitute the minimal requirements for any laboratory offering assisted reproduction techniques (ART). In the understanding that the embryologist has a responsibility for the correct and justified application of ART in the laboratory, the implementation of these guidelines requires a quality management programme to be in place that encompasses and integrates the operative units, the processes and procedures that represent the core of ART clinics. In March 2004, the European Parliament issued the Directive 2004/23/EC 'On setting standards of quality and safety for the donation, procurement, testing, processing, preservation, storage and distribution of human tissues and cells'. The Directive applies to human tissues and cells, including fresh or frozen reproductive cells for application to the human body, and is mainly concerned with increasing quality and safety through the implementation of a quality management system. Therefore, the European Society of Human Reproduction and Embryology (ESHRE) undertook a series of initiatives aiming to promote assurance of good laboratory practice and to define the concept of qualified embryologists. One ESHRE initiative was to revise the guidelines for good practice in IVF laboratories, not only in response to the need of embryologists for support and guidance in their duties, but also as a complement to the requirements issued by the Tissue and Cell Directive. The SIG in Embryology hopes that this document may assist the laboratory staff to operate according to the requirements of harmonization, implementation, inspection and certification that are now common to all European member states.

Background: Dialogue between the oocyte and cumulus cells is essential for oocyte maturation. A prospective laboratory research project was designed to evaluate transcription of specific genes in cumulus cells harvested before intracytoplasmic sperm injection from pre-ovulatory follicles, according to individual oocyte nuclear maturity and developmental competence. Genes were chosen because their expression was induced by the LH peak [Steroidogenic Acute Regulatory protein (STAR), Cyclooxygenase 2 (COX2 or PTGS2), Amphiregulin (AREG)] or because they were involved in oocyte lipidic metabolism [Stearoyl-Coenzyme A Desaturase 1 and 5 (SCD1 and SCD5)] or in gap-junctions [Connexin 43 (CX43 or GJA1)]., Methods: mRNA levels in cumulus cells were assessed by real-time PCR., Results: Expression levels of all genes investigated, except Cx43, were increased after resumption of meiosis. Nuclear maturation was thus associated with increased expression of STAR, COX2, AREG, SCD1 and SCD5 by cumulus cells. When considering only cumulus associated with metaphase II oocytes, gene expression was independent of morphological status at Day 2. In contrast, transcript levels were lower and distributed over a narrower range in cumulus enclosing oocytes achieving blastocyst development at Day 5/6 than in cumulus enclosing oocytes unable to develop beyond the embryo stage., Conclusion: Further developmental potential from embryo to blastocyst stage was associated with lower expression in a narrow range for these genes.

Background: Non-invasive and routine developmental markers are available to select the most viable embryo; however their respective values in terms of blastocyst development potential remain difficult to distinguish., Methods: During this prospective study, the sequential growth of 4042 embryos individually cultured from day 1 to day 5/6 was recorded. Pronuclear morphology on day 1, and early cleavage, cell number and fragmentation rate on day 2 were evaluated for each zygote. Additionally, blastocyst transfers were analysed with regard to their implantation ability and early embryo development parameters., Results: Once adjusted to each other, each of the four parameters remained related to blastocyst development. Early cleavage and cell number on day 2 were the most powerful parameters to predict the development of a good morphology blastocyst at day 5. Moreover, whereas transfers of a good morphology blastocyst were associated with high implantation and live birth rates, parameters of early development were not helpful in predicting their implantation ability., Conclusions: The combination of all four parameters allowed the prediction of blastocyst development with an area under the receiver operating characteristics curve of 0.688, which represents a fairly low prediction of embryo viability. Such results indicate that it is necessary to search for additional criteria, including the ability of the blastocyst to develop.

Background: This study was designed to determine the efficacy of a programme using frozen donor semen in a cohort of patients returning for treatment after previously conceiving through donor insemination (DI)., Methods: The cohort included 222 couples with secondary infertility (previous live birth) in one University Hospital Centre. The treatment sequence involved DI cycles until completion. Live births, drop-out for personal or medical reasons and recourse to IVF with donor semen (IVF-D) were recorded for all patients. Live births were expressed as both rate per cycle and crude cumulative rate., Results: At the end of the DI cycles, 65% of couples in the cohort achieved second parenthood. Most of them (77%) succeeded after only four DI cycles. The majority of couples who stopped treatment did so for personal reasons., Conclusions: Patients involved in a second parenthood project belong to a 'selected' population. Management and counselling of such patients need to reconcile the early efficacy of DI cycles, the invasiveness of the IVF-D procedure and the availability of donor semen.

Background: This study was designed to determine the crude cumulative live-birth rates in a cohort initiating frozen donor semen treatment until completion., Methods: This cohort study included 588 couples with primary infertility in one University Hospital centre. The treatment sequence involved first artificial insemination (AID) followed by IVF if necessary (IVF-D). Live birth, drop-out for personal or medical reasons and recourse to IVF-D were recorded for all patients. Live births and drop-out were expressed both as rates per cycle and crude cumulative rates., Results: At the completion of AID and IVF-D cycles, 406 couples in the cohort (69%) achieved a live-birth and 182 couples (31%) discontinued treatment. In most cases, couples stopped treatment for personal reasons (74%) whereas fewer couples were denied further treatment for medical reasons (26%)., Conclusions: This is the first report on the crude cumulative live-birth rate in a cohort after AID and IVF-D cycles. Although calculation based on crude cumulative live-birth rate shows lower results in comparison with life table analysis, this method allows patients to obtain an insight into their actual chances of achieving a successful pregnancy.

Background: The purpose of this study was to evaluate the respective influences of blastomere survival and resumption of mitosis on the outcome of frozen-thawed embryos., Methods: A retrospective analysis was performed in our centre on 363 thawing cycles, involving 4-cell day 2 grade 1 embryos with <10% fragmentation., Results: A higher implantation rate per transferred embryo was observed when all transferred embryos were characterized by fully intact blastomeres (100% blastomere survival) as compared with damaged embryos (50 or 75% blastomere survival) (22.0 versus 7.2%; P < 0.0001). Moreover, the implantation rate per transferred embryo was significantly higher for cleaved embryos compared with uncleaved embryos (19.7 versus 3%; P < 0.0001). Transfer of fully intact, cleaved embryos resulted in the highest implantation rates compared with transfer of damaged and uncleaved embryos (27.4 versus 0%; P < 0.0001). Intermediate implantation rates were observed when only one of the two criteria was fulfilled (13 versus 11% respectively; P > 0.05). Multivariate analysis showed that the clinical pregnancy rate was influenced by both criteria (odds ratio = 3.4 for transfer of embryos with six or more cells versus embryos with less than six cells., Conclusion: The results of our study suggest that the most important factor to predict further embryo development is the total number of blastomeres in transferred embryos, however they are obtained (good survival and/or resumption of mitosis).

A case report of delayed delivery of a quadruplet pregnancy is presented. This quadruplet pregnancy resulted from in-vitro fertilization. To our knowledge, this case represents the first report of quadruplets delivered on three separate days using the technique of delayed interval delivery. All infants survived and are healthy 2 years later.