Cyclic FEE Peptide Improves Human Sperm Movement Parameters without Modification of Their Energy Metabolism.

Cyclic fertilin peptide (cFEE: phenylalanine, glutamic acid; glutamic acid) improves gamete interaction in humans. We investigate whether it could be via improvement of sperm movement parameters and their mitochondrial ATP production. Sperm movement parameters were studied using computer-assisted sperm analysis (CASA) in sperm samples from 38 patients with normal sperm in medium supplemented with cyclic fertilin against a control group. Sperm mitochondrial functions were studied using donor's sperm, incubated or not with cFEE. It was evaluated by the measurement of their ATP production using bioluminescence, their respiration by high resolution oxygraphy, and of mitochondrial membrane potential (MMP) using potentiometric dyes and flow cytometry. cFEE significantly improved sperm movement parameters and percentage of hyperactivated sperm. Impact of inhibitors showed OXPHOS as the predominant energy source for sperm movement. However, cFEE had no significant impact on any of the analyzed mitochondrial bioenergetic parameters, suggesting that it could act via a more efficient use of its energy resources.

Live birth rate following frozen-thawed blastocyst transfer is higher with blastocysts expanded on Day 5 than on Day 6.

STUDY QUESTION: The aim of this study was to evaluate the live birth rate (LBR) after frozen-thawed Day 5 (D5) and Day 6 (D6) blastocyst transfers. SUMMARY ANSWER: LBR following frozen-thawed blastocyst transfer is significantly lower with D6 than with D5 blastocyst regardless of embryo quality. WHAT IS KNOWN ALREADY: During fresh embryo transfer cycles, pregnancy rates (PR) are significantly higher when transferring blastocysts expanded on D5 compared with slow developing blastocysts (D6). In programmed thawed blastocyst transfer (TBT) cycles, the same clinical outcomes should be expected when transferring D5 or D6 blastocysts because of endometrial/embryonic synchronization due to hormonal priming of endometrial receptivity. However, the impact of delayed blastocyst expansion at D6 on clinical outcomes remains unclear. Some reports have shown higher PRs after D5 TBT compared with those of D6, while others have shown equivalent TBT outcomes after D5 and D6 cryopreserved blastocysts transfers. STUDY, DESIGN, SIZE, DURATION: This retrospective cohort follow-up study included 1347 single autologous frozen-thawed blastocyst transfers performed between January 2012 and December 2015 at a tertiary care university hospital. PARTICIPANTS/MATERIALS, SETTING, METHODS: All of the patients scheduled for TBT were allocated to two groups according to the day of blastocyst expansion: on D5 (n = 994) or on D6 (n = 353). The primary outcome was LBR per embryo transfer in the first blastocyst thawing cycle. Secondary outcomes were clinical pregnancy rate (cPR), early miscarriage rate and neonatal outcomes following TBT for the two groups. Statistical analyses were conducted using univariate and multivariate logistic regression model. MAIN RESULTS AND THE ROLE OF CHANCE: The LBR was significantly increased in the D5 group compared to the D6 group [294/994 (29.6%) versus 60/353 (17.0%); P < 0.001]. The cPR was also higher when blastocysts were vitrified on D5 compared with those vitrified on D6 [429/994 (43.2%) versus 95/353 (26.9%); P < 0.001]. No significant differences were found between groups in terms of early miscarriage rate (P = 0.862). More good-quality embryos (defined as an B3-B4 or B5 embryo ≥BB according to the grading scale proposed by Gardner) were transferred in the D5 group than in the D6 group [807 (81.2%) versus 214 (60.6%); P < 0.001]. However, a comparison of TBT cycles with equal embryo quality (good versus low) also supported the superiority of D5 blastocysts. Concerning neonatal outcomes, the D5 group infants had a lower mean birth weight compared to those of the D6 group (P = 0.001). In addition, a significantly shorter gestational age at birth is reported in the D5 blastocyst group as compared to the D6 group (P = 0.004). After multivariate logistic regression taking into account potential confounders such as the women's age, number of previous IVF/ICSI procedures, the day of the blastocyst vitrification (D5 or D6) and embryo quality, blastocyst expansion at D6 was independently associated with a significant decrease in LBR compared to D5 expanded-blastocysts (OR 0.52; 95% CI 0.38-0.72; P < 0.001). LIMITATIONS, REASONS FOR CAUTION: The poor predictive value of the morphological approach in embryo selection could constitute a limitation in this study. However, blastocyst quality was evaluated similarly in both groups. WIDER IMPLICATIONS OF THE FINDINGS: The LBR following frozen-thawed blastocyst transfer was significantly lower with D6 than with D5 blastocysts, regardless of their quality. These results could affect cryopreservation procedures as they suggest that the use of D5-expanded blastocysts for TBT may be preferred in order to shorten the time of conceiving. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was obtained for this study. None of the authors have any competing interests to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Extended culture of poor-quality supernumerary embryos improves ART outcomes.

PURPOSE: The aims of this study were to investigate the possible benefits of extending the culture of poor-quality day-2 embryos (PQE) versus good-quality embryos (GQE) and to identify factors associated with pregnancy and live birth when transferring frozen-thawed blastocysts originating from GQE and PQE. METHODS: This is a retrospective cohort follow-up study performed between November 2012 and February 2015 at the IVF Laboratory Unit of Cochin University Hospital (Paris, France) including 3108 day-2 supernumerary embryos resulting from 1237 IVF/ICSI cycles. RESULTS: Total blastulation rate was 67.2% from GQE and 48.7% from PQE. Percentage of good-quality blastocysts was 60.7 and 47.9% respectively including 14.7 and 7.3% top-quality blastocysts. A total of 150 blastocysts originating from GQE and 729 from PQE were frozen, and then, 37 and 164 were thawed and transferred respectively resulting in 19 (51.4%) and 61 (37.9%) clinical pregnancies with 13 (35.1%) deliveries from GQE and 32 (19.9%) from PQE (p = 0.046) without any difference in neonatal outcomes. Quality of blastocysts that resulted in live birth was similar in the two groups. Women < 35 years old and day-5 blastocyst expansion were predictive of pregnancy and live birth. CONCLUSIONS: (i) PQE are able to reach the blastocyst stage, to implant, and to give healthy babies and (ii) women age and day of blastocyst expansion are predictive of pregnancy and live birth.

Sperm fluorescence in situ hybridization study in nine men carrying a Robertsonian or a reciprocal translocation: relationship between segregation modes and high-magnification sperm morphology examination.

OBJECTIVE: To evaluate whether observation of spermatozoa at × 6,100 magnification can distinguish between those with and without a balanced chromosomal content. DESIGN: Retrospective research study. SETTING: Genetics laboratory of a university hospital and in vitro fertilization center. PATIENT(S): Six men carrying a reciprocal translocation and three men with a Robertsonian translocation. INTERVENTION(S): Sperm fluorescence in situ hybridization (FISH) with a specific set of three probes for each translocation for determining chromosomal content, performed on both unselected spermatozoa and on spermatozoa selected at × 6,100 magnification according to the Cassuto-Barak classification. MAIN OUTCOME MEASURE(S): Chromosomal content in unselected and selected spermatozoa. RESULT(S): Chromosomal translocations lead to gametes carrying either a balanced or an unbalanced karyotype in offspring and consequently to changes in chromosome position within sperm nucleus and potentially in nuclear morphology. In the unselected spermatozoa, the rate of chromosomally balanced nuclei ranged from 37.1% to 52.6% and from 70% to 88.6% in reciprocal and Robertsonian translocations, respectively, which is in agreement with published data. In selected spermatozoa, there was no statistically significant difference between the rates of segregation modes when compared with their frequencies in unselected sperm cells. CONCLUSION(S): The observation of spermatozoa at high-magnification in translocation carriers cannot be used to select sperm cells with a balanced chromosomal content.