Can Microfluidics Improve Sperm Quality? A Prospective Functional Study.

The same sperm selection techniques in assisted reproduction clinics have remained largely unchanged despite their weaknesses. Recently, microfluidic devices have emerged as a novel methodology that facilitates the sperm selection process with promising results. A prospective case-control study was conducted in two phases: 100 samples were used to compare the microfluidic device with Density Gradient, and another 100 samples were used to compare the device with the Swim-up. In the initial phase, a significant enhancement in progressive motility, total progressive motile sperm count, vitality, morphology, and sperm DNA fragmentation were obtained for the microfluidic group compared to Density Gradient. Nevertheless, no statistically significant differences were observed in sperm concentration and chromatin structure stability. In the subsequent phase, the microfluidic group exhibited significant increases in sperm concentration, total progressive motile sperm count, and vitality compared to Swim-up. However, non-significant differences were seen for progressive motility, morphology, DNA structure stability, and DNA fragmentation. Similar trends were observed when results were stratified into quartiles. In conclusion, in a comparison of microfluidics with standard techniques, an improvement in sperm quality parameters was observed for the microfluidic group. However, this improvement was not significant for all parameters.

Embryo long-term storage does not affect assisted reproductive technologies outcome: analysis of 58,001 vitrified blastocysts over 11 years.

BACKGROUND: Recently, the potential detrimental effect that the duration of storage time may have on vitrified samples has raised some concerns, especially when some studies found an association between cryostorage length and decreased clinical results. OBJECTIVE: This study aimed to evaluate the effects of the storage time length of day-5 vitrified blastocysts in 2 study groups: freeze-all cycles and nonelective frozen embryo transfers. STUDY DESIGN: This was a retrospective study that included 58,001 vitrified/warmed day-5 blastocysts from 2 different populations, according to the reason for frozen embryo transfer. Elective frozen embryo transfer comprised freeze-all cycles (N=16,615 blastocysts and 16,615 patients) in which only single embryo transfers and only the first frozen embryo transfer were included. The nonelective frozen embryo transfer group included 41,386 embryos from 25,571 patients where frozen embryo transfer took place using supernumerary embryos after fresh embryo transfer. All the possible frozen embryo transfers were included. Both single embryo transfer and double embryo transfers were included. Donor and autologous oocytes were used. The period covered by this study was 11 years. The blastocyst sample was clustered into deciles, which provided specific storage duration categories. The main outcome was the live birth rate, and secondary outcomes were embryo survival, miscarriage, and clinical and ongoing pregnancy rates according to storage duration. The impact of storage time was assessed by univariable analyses in both groups. The comparison was made between each decile and the last one. A multivariable logistic regression analysis was conducted, including the variables with significant association found in the univariate analysis. Student t test and chi-square tests, or an analysis of variance, were used wherever appropriate. P<.05 was considered statistically significant. RESULTS: There were statistical differences in baseline characteristics of patients included in the study groups. Storage durations ranged from ≤0.67 to ≥4.34 and from ≤1.8 to ≥34.81 months in freeze-all and nonelective frozen embryo transfer, respectively. Embryo survival did not show statistical differences across the categories of storage time in freeze-all and nonelective frozen embryo transfer groups. Statistical differences were found for the live birth rate across some, but not all, the subgroups of storage duration. The multivariable analysis showed no association between storage time and the live birth rate in both groups (nonsignificant). Blastocyst quality, body mass index, number of retrieved oocytes, endometrial preparation, male factor, and uterine factor were related to the drop in the live birth rate in the freeze-all group (P<.05). In the nonelective frozen embryo transfer group, the variables that showed significant association with the live birth rate were age at retrieval and frozen embryo transfer, type of frozen embryo transfer (single embryo transfer or double embryo transfers), number of retrieved oocytes, body mass index, endometrial preparation, origin of sperm sample, and female factor. CONCLUSION: This large study demonstrated no association between storage time and clinical outcome. Other variables, such as the patient's age, embryo quality, body mass index, and etiology, are somewhat responsible for impacting the outcome. This provides evidence for the safety of embryo vitrification, even after long storage periods. This is reassuring for both in vitro fertilization practitioners and patients undergoing frozen embryo transfer of either elective or nonelective embryos.

Deciphering a shared transcriptomic regulation and the relative contribution of each regulator type through endometrial gene expression signatures.

BACKGORUND: While various endometrial biomarkers have been characterized at the transcriptomic and functional level, there is generally a poor overlap among studies, making it unclear to what extent their upstream regulators (e.g., ovarian hormones, transcription factors (TFs) and microRNAs (miRNAs)) realistically contribute to menstrual cycle progression and function. Unmasking the intricacies of the molecular interactions in the endometrium from a novel systemic point of view will help gain a more accurate perspective of endometrial regulation and a better explanation the molecular etiology of endometrial-factor infertility. METHODS: An in-silico analysis was carried out to identify which regulators consistently target the gene biomarkers proposed in studies related to endometrial progression and implantation failure (19 gene lists/signatures were included). The roles of these regulators, and of genes related to progesterone and estrogens, were then analysed in transcriptomic datasets compiled from samples collected throughout the menstrual cycle (n = 129), and the expression of selected TFs were prospectively validated in an independent cohort of healthy participants (n = 19). RESULTS: A total of 3,608 distinct genes from the 19 gene lists were associated with endometrial progression and implantation failure. The lists' regulation was significantly favoured by TFs (89% (17/19) of gene lists) and progesterone (47% (8 /19) of gene lists), rather than miRNAs (5% (1/19) of gene lists) or estrogen (0% (0/19) of gene lists), respectively (FDR < 0.05). Exceptionally, two gene lists that were previously associated with implantation failure and unexplained infertility were less hormone-dependent, but primarily regulated by estrogen. Although endometrial progression genes were mainly targeted by hormones rather than non-hormonal contributors (odds ratio = 91.94, FDR < 0.05), we identified 311 TFs and 595 miRNAs not previously associated with ovarian hormones. We highlight CTCF, GATA6, hsa-miR-15a-5p, hsa-miR-218-5p, hsa-miR-107, hsa-miR-103a-3p, and hsa-miR-128-3p, as overlapping novel master regulators of endometrial function. The gene expression changes of selected regulators throughout the menstrual cycle (FDR < 0.05), dually validated in-silico and through endometrial biopsies, corroborated their potential regulatory roles in the endometrium. CONCLUSIONS: This study revealed novel hormonal and non-hormonal regulators and their relative contributions to endometrial progression and pathology, providing new leads for the potential causes of endometrial-factor infertility.

Medroxyprogesterone acetate: an alternative to GnRH-antagonist in oocyte vitrification for social fertility preservation and preimplantation genetic testing for aneuploidy.

RESEARCH QUESTION: Can medroxyprogesterone acetate (MPA) be used as a pituitary suppressor instead of a gonadotrophin releasing hormone (GnRH) antagonist during ovarian stimulation in elective fertility preservation and preimplantation genetic testing for aneuploidy (PGT-A) cycles? DESIGN: A multicentre, retrospective, observational, cohort study conducted in 11 IVIRMA centres affiliated to private universities. Of a total of 1652 cycles of social fertility preservation, 267 patients were stimulated using a progestin-primed ovarian stimulation protocol (PPOS), and 1385 patients received a GnRH antagonist. In the PGT-A cycles, 5661 treatments were analysed: 635 patients received MPA and 5026 patients received GnRH antagonist. A further 66 fertility preservation and 1299 PGT-A cycles were cancelled. All cycles took place between June 2019 and December 2021. RESULTS: In the social fertility preservation cycles, the number of mature oocytes vitrified in MPA was similar to the number of those treated with an antagonist, a trend that was seen regardless of age (≤35 or >35 years). In the PGT-A cycles, no differences were found in number of metaphase II, two pronuclei, number of biopsied embryos (4.4 ± 3.1 versus 4.5 ± 3.1), rate of euploidy (57.9% versus 56.4%) or ongoing pregnancy rate (50.4% versus 47.1%, P = 0.119) between the group receiving MPA versus a GnRH antagonist, whereas the clinical miscarriage rate was higher in the antagonist group (10.4% versus 14.8%, P = 0.019). CONCLUSIONS: Administration of PPOS yields similar results to GnRH antagonists in oocytes retrieved, rate of euploid embryos and clinical outcome. Hence, PPOS can be recommended for ovarian stimulation in social fertility preservation and PGT-A cycles, as it allows greater patient comfort.

COVID-19 mRNA vaccines have no effect on endometrial receptivity after euploid embryo transfer.

RESEARCH QUESTION: Does the COVID-19 vaccination affect endometrial receptivity after single euploid embryo transfer, measured by sustained implantation rate? DESIGN: A retrospective cohort study analysing two groups of single euploid embryo transfers using own oocytes: one historical cohort of 3272 transfers 1 year before the pandemic; and one comprising 890 transfers in women previously vaccinated with mRNA vaccines against severe acute respiratory syndrome coronavirus 2. The main outcomes were clinical pregnancy rate (CPR) and sustained implantation rate (SIR) per embryo transfer. These outcomes were compared between non-vaccinated and vaccinated women, and women who had received one and two doses. Lastly, vaccinated women were divided into quartiles according to the time from last dose to embryo transfer. RESULTS: Similar CPR and SIR were found between non-vaccinated and vaccinated women, and the odds ratio for both outcomes was not statistically significant after being controlled for potential confounders (OR 0.937, 95% CI 0.695 to 1.265 and OR 0.910, 95% CI 0.648 to 1.227 respectively). Within the vaccinated group, women who had received one or two doses also had similar outcomes. In addition, no differences were found according to the time interval from vaccination to embryo transfer. CONCLUSION: The administration of mRNA vaccines against COVID-19 had no effect on endometrial receptivity and embryo implantation, regardless of the number of doses and time interval from vaccination to embryo transfer. The potential negative effect of the vaccine on endometrial receptivity and reproductive outcomes is reassuring for patients in the process of undergoing assisted reproductive treatment.

The higher the score, the better the clinical outcome: retrospective evaluation of automatic embryo grading as a support tool for embryo selection in IVF laboratories.

STUDY QUESTION: Is the automatic embryo grading function of specific time-lapse systems clinically useful as a decision support tool for IVF laboratories? SUMMARY ANSWER: Blastocyst grading according to the automatic scoring system is directly associated with the likelihood of implantation and live birth, at least in treatments without preimplantation genetic testing for aneuploidy (PGT-A). WHAT IS KNOWN ALREADY: Several embryo selection algorithms have been described since the introduction of time-lapse technology in IVF laboratories, but no one algorithm has yet been sufficiently consolidated for universal use. Multicentric models based on automated grading systems offer promise for standardization of embryo selection. STUDY DESIGN, SIZE, DURATION: A retrospective cohort study was performed including 1678 patients who underwent IVF treatments between 2018 and 2020 and whose embryos (n = 12 468) were cultured in time-lapse systems. PARTICIPANTS/MATERIALS, SETTING, METHODS: After obtaining the required parameters (division time to 2, 3, 4 and 5 cells; time of blastocyst formation; inner cell mass quality; and trophectoderm quality), the automatic embryo score was calculated using the software included in the appropriate workstation. First, embryo score was compared with conventional morphological quality and the subsequent clinical outcomes of 1952 single blastocyst transfers. Second, we quantified the contribution of the automatic embryo score and conventional morphological grade to implantation and live birth outcome with multivariate logistic regression analysis in different patient populations. MAIN RESULTS AND THE ROLE OF CHANCE: A higher embryo score was associated with a better clinical outcome of IVF treatment. The mean of the automatic embryo score varied significantly (P < 0.001) among embryos with different morphological categories, between euploid and aneuploid embryos, between embryos resulting in positive versus negative pregnancy, between implanted and non-implanted embryos, and between embryos resulting in positive and negative live birth. Embryo score was related to the odds of implantation and live birth in the oocyte donation program (odds ratio (OR)=1.29; 95% CI [1.19-1.39]; P < 0.001 for implantation and OR = 1.26; 95% CI [1.16-1.36]; P < 0.001 for live birth) and in conventional treatments with autologous oocytes (OR = 1.38; 95% CI [1.24-1.54]; P < 0.001 for implantation and OR = 1.47; 95% CI [1.30-1.65]; P < 0.001 for live birth). There was no significant association of embryo score with implantation or live birth in treatments involving PGT-A. LIMITATIONS, REASONS FOR CAUTION: This study is limited by its retrospective nature. Further prospective randomized trials are required to confirm the clinical impact of these findings. The single-center design should be taken into account when considering the universal application of the model. WIDER IMPLICATIONS OF THE FINDINGS: Evidence of the clinical efficiency of automated embryo scoring for ranking embryos with different morphological grade and potential in order to achieve higher implantation and live birth rates may make it a decision support tool for embryologists when selecting blastocysts for embryo transfer. STUDY FUNDING/COMPETING INTEREST(S): This research has been funded by a grant from the Ministry of Science, Innovation and Universities FIS (PI21/00283) awarded to M.M. There are no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Treatment with Calcium Ionophore Improves The Results in Patients with Previous Unsuccessful Attempts at The Fertilization: A Cohort Study.

BACKGROUND: The objective of this study is to evaluate artificial oocyte activation (AOA) with calcium ionophore (CaI) in a subsequent attempt at fertilisation in patients after extremely low or failed fertilisation. We assessed improvements in fertilisation, implantation and pregnancy rates as well as cancellation rates in these patients. Finally, was evaluated the result testing in addition to delivery rate and obstetric outcomes in children born after AOA. MATERIALS AND METHODS: This was a retrospective observational study conducted in an IVF laboratory of an IVI clinic (IVIRMA Valencia, Spain). One group (509 mature oocytes from 66 patients) received a first intracytoplasmic sperm injection (ICSI) without AOA, which resulted in either a failed fertilisation or very low values (<30%). This group was compared with a second group (616 mature oocytes from the same 66 patients) that used AOA. Outcome was compared by McNemar's test and the dependent t tests. RESULTS: AOA plus CaI resulted in enhanced fertilisation (51 vs. 13.1%), ongoing pregnancy (47 vs. 21.7%), and implantation (31.1 vs. 13.1%) rates, and less chances for cancelling the cycle (22.7 vs. 69.3%). There were no observed adverse effects in obstetric and perinatal outcomes after the use of AOA. CONCLUSION: Our findings support the use of AOA for a given population of patients where fertilisation was affected during previous attempts. After AOA, we observed a significant increase in reproductive success due to the increased number of embryos available for embryo selection and, therefore, enhanced chances for success. The use of this artificial technique is comforting after checking non-existence of detrimental effects on the offspring.

Machine Learning-Based Approach Highlights the Use of a Genomic Variant Profile for Precision Medicine in Ovarian Failure.

Ovarian failure (OF) is a common cause of infertility usually diagnosed as idiopathic, with genetic causes accounting for 10-25% of cases. Whole-exome sequencing (WES) may enable identifying contributing genes and variant profiles to stratify the population into subtypes of OF. This study sought to identify a blood-based gene variant profile using accumulation of rare variants to promote precision medicine in fertility preservation programs. A case-control (n = 118, n = 32, respectively) WES study was performed in which only non-synonymous rare variants <5% minor allele frequency (MAF; in the IGSR) and coverage ≥ 100× were considered. A profile of 66 variants of uncertain significance was used for training an unsupervised machine learning model to separate cases from controls (97.2% sensitivity, 99.2% specificity) and stratify the population into two subtypes of OF (A and B) (93.31% sensitivity, 96.67% specificity). Model testing within the IGSR female population predicted 0.5% of women as subtype A and 2.4% as subtype B. This is the first study linking OF to the accumulation of rare variants and generates a new potential taxonomy supporting application of this approach for precision medicine in fertility preservation.

Elevated serum progesterone does not impact euploidy rates in PGT-A patients.

PURPOSE: Some women undergoing stimulated cycles have elevated serum progesterone (P) on the day of ovulation trigger, but its effect on embryo quality is unclear. We analyze embryo quality among patients with high and low serum P undergoing preimplantation genetic testing for aneuploidy (PGT-A). METHODS: This retrospective study included 1597 patients divided into two groups by serum P values: < 1.5 ng/mL or ≥ 1.5 ng/mL. A gonadotrophin-releasing hormone (GnRH) antagonist protocol was established for each patient. Serum P levels were measured on the day of triggering. Propensity score matching and Poisson regression were done. Age, body mass index, and ovarian sensitivity index were also compared. RESULTS: Elevated serum P was not significantly associated with euploid embryo rate or other embryo-quality variables evaluated in our study. Age was the only variable associated with euploidy rate (per MII oocyte, P < 0.001; per biopsied embryo, P = 0.008), embryo biopsy rate (P < 0.001), absolute number of euploid embryos (P = 0.008), and top-quality embryo rate (P = 0.008). Categorical variables decreased in value for every year of increased age in patients with high serum P. CONCLUSIONS: Elevated serum P did not affect the number of euploid and good-quality embryos for transfer in GnRH antagonist intracytoplasmic sperm injection (ICSI) cycles. Contrary to the clear influence of premature P elevation on endometrial receptivity based on literature, our results may help to tip the balance towards the absence of a negative effect of P elevation on embryo competence. More studies are needed to fully understand the effect of P elevation on reproductive outcomes.

Oocyte vitrification for fertility preservation for both medical and nonmedical reasons.

Growing evidence of successful outcomes achieved with the oocyte vitrification technique has greatly contributed to its application in the field of fertility preservation (FP). The population that can benefit from FP includes women at a risk of losing their ovarian function because of either iatrogenic causes or natural depletion of their ovarian reserve. Therefore, oncological patients and healthy women who wish to delay motherhood for various reasons-elective FP-are currently being offered this option. Satisfactory oocyte survival rates and clinical outcomes, including cumulative live birth rates, have been reported in recent years. These studies show that age at oocyte retrieval strongly affects reproductive prognosis after FP. Therefore, elective FP patients should be encouraged to decide before they reach the age of 35 years to significantly increase their chances of success. The effect of age has also been observed in patients with cancer and women diagnosed with endometriosis. The reproductive outcome after FP is worse in patients with cancer, but a direct association between the disease and reproductive outcome is yet to be proven. Young patients (≤35 years) with endometriosis who have undergone cystectomy before oocyte retrieval for FP have worse outcomes than nonoperated women in age-matched groups. In addition, the number of oocytes used per patient is closely related to success in all populations, with considerable improvement in the result with the addition of a few oocytes, especially in healthy young patients.

Differential sperm proteomic profiles according to pregnancy achievement in intracytoplasmic sperm injection cycles: a pilot study.

PURPOSE: To describe the proteomic profiles in semen samples and define the differences in sperm proteomic profiles among samples that ultimately achieved pregnancy (P) via intracytoplasmic sperm injection (ICSI) in an oocyte donation program and those that were unsuccessful (NP). METHODS: Prospective, analytical, observational nested case and control study evaluating the proteomic profile of spermatozoa from patients' ejaculates where pregnancies were (group pregnant (P), n= 4) or were not (group non-pregnant (NP), n=4) achieved after ICSI in an oocyte donation program aiming to standardize female factor. Proteins were separated and analyzed by means of SWATH-MS) and compared between P/NP groups to identify sperm biomarkers of fertility/infertility. Proteins are available via ProteomeXchange. RESULTS: We identified and quantified 2228 proteins, with 37 significantly higher in the P group and 16 higher in NP. Enrichment analysis revealed that the increased proteins in P group sperm were related to motility, anaerobic metabolism, and protein biosynthesis functions, while the increased proteins in the NP group were involved in protein biosynthesis, protein folding, aerobic metabolism, and signal transduction, all of which are functions not previously described as influencing sperm success. Some proteins identified (e.g., SLC2A3, or CD81) are located in the cell membrane and thus may be employed to select spermatozoa by magnetic-activated cell sorting (MACS). CONCLUSION(S): This work revealed differences in the proteomic profiles of sperm samples successful in achieving pregnancy and those that were not, expanding our understanding of sperm function and infertility-related molecular markers, and enabling the future development of male fertility diagnostic tools and therapies.

Prediction of embryo survival and live birth rates after cryotransfers of vitrified blastocysts.

RESEARCH QUESTION: Which pre-vitrification parameters are the most predictive of survival and live birth in vitrified-warmed blastocyst transfer cycles? DESIGN: A retrospective study including 11,936 warmed blastocysts. Pre-vitrification morphological parameters analysed for blastocysts included day of vitrification; blastocyst expansion degree; trophoectoderm grade (A, B and C); and inner cell mass grade (A, B and C). Univariate and multivariate generalized estimating equations models were used to analyse survival, clinical pregnancy and live birth rate. A stepwise regression analysis was conducted to select and classify by order which outcomes were the most predictive. RESULTS: The odds of survival increased almost twice for blastocysts with lower expansion degree (OR 1.92; 95% CI 1.37 to 2.69; P < 0.001) and by about 50% for blastocysts vitrified on day 5 (OR 1.56; 95% CI 1.27 to 1.89; P < 0.001). Multivariate generalized estimating equations model showed that trophectoderm grade followed by the day of vitrification were the most significant predictors of live birth. The odds of live birth increased nearly three times for blastocysts with trophectoderm graded as A compared with those with trophectoderm graded as C (OR 2.85; 95% CI 2.48 to 3.27; P < 0.001), and double for blastocysts vitrified on day 5 compared with those vitrified on day 6 (OR 2.22; 95% CI 1.97 to 2.49; P < 0.001). The odds of live birth also increased in higher expansion degree blastocysts. CONCLUSIONS: Blastocysts vitrified on day 5 and those with higher trophoectoderm grade should be given priority when warming.

Number needed to freeze: cumulative live birth rate after fertility preservation in women with endometriosis.

RESEARCH QUESTION: How does the number of oocytes used affect the cumulative live birth rate (CLBR) in endometriosis patients who had their oocytes vitrified for fertility preservation? DESIGN: Retrospective observational study including data from 485 women with endometriosis who underwent fertility preservation from January 2007 to July 2018. Survival curves and Kaplan-Meier plots were used to analyse the CLBR according to the number of vitrified oocytes used. Endometriosis curves were compared with plots developed using elective fertility preservation (EFP) patients as control group. Log-rank, Breslow and Tarone-Ware tests were used to compare the survival curves. RESULTS: The CLBR increased as the number of oocytes used per patient rose, reaching 89.5% (95% confidence interval [CI] 80.0-99.1%) using 22 oocytes. Higher outcomes were observed in young women (≤35 years old versus >35 years old). In the younger group, the CLBR was 95.4% (95% CI 87.2-103.6%) using approximately 20 oocytes versus 79.6% (95% CI 58.1-101.1%) in older women (log-rank [Mantel-Cox] P = 0.002). The mean age was higher in EFP patients (37.2 ± 4.9 versus 35.7 ± 3.7; P < 0.001). The outcome was better in the endometriosis group as compared with EFP: a CLBR of 89.5% (95% CI 80.0-99.1%) versus 59.9% (95% CI 51.4-68.6%) when 22 oocytes were used (log-rank [Mantel-Cox] P < 0.00001). CONCLUSION: The probability of live birth increases as the number of oocytes used increases in patients with endometriosis, but better outcomes were observed among young women. The information provided here may be of interest to both patients and treating physicians for counselling purposes.

Impact of low serum progesterone levels on the day of embryo transfer on pregnancy outcome: a prospective cohort study in artificial cycles with vaginal progesterone.

STUDY QUESTION: Is there a serum progesterone (P) threshold on the day of embryo transfer (ET) in artificial endometrium preparation cycles below which the chances of ongoing pregnancy are reduced? SUMMARY ANSWER: Serum P levels <8.8 ng/ml on the day of ET lower ongoing pregnancy rate (OPR) in both own or donated oocyte cycles. WHAT IS KNOWN ALREADY: We previously found that serum P levels <9.2 ng/ml on the day of ET significantly decrease OPR in a sample of 211 oocyte donation recipients. Here, we assessed whether these results are applicable to all infertile patients under an artificial endometrial preparation cycle, regardless of the oocyte origin. STUDY DESIGN, SIZE, DURATION: This prospective cohort study was performed between September 2017 and November 2018 and enrolled 1205 patients scheduled for ET after an artificial endometrial preparation cycle with estradiol valerate and micronized vaginal P (MVP, 400 mg twice daily). PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients ≤50 years old with a triple-layer endometrium ≥6.5 mm underwent transfer of one or two blastocysts. A total of 1150 patients treated with own oocytes without preimplantation genetic testing for aneuploidies (PGT-A) (n = 184), own oocytes with PGT-A (n = 308) or donated oocytes (n = 658) were analyzed. The primary endpoint was the OPR beyond pregnancy week 12 based on serum P levels measured immediately before ET. MAIN RESULTS AND THE ROLE OF CHANCE: Women with serum P levels <8.8 ng/ml (30th percentile) had a significantly lower OPR (36.6% vs 54.4%) and live birth rate (35.5% vs 52.0%) than the rest of the patients. Multivariate logistic regression showed that serum P < 8.8 ng/ml was an independent factor influencing OPR in the overall population and in the three treatment groups. A significant negative correlation was observed between serum P levels and BMI, weight and time between the last P dose and blood tests and a positive correlation was found with age, height and number of days on HRT. Multivariate logistic regression showed that only body weight was an independent factor for presenting serum P levels <8.8 ng/ml. Obstetrical and perinatal outcomes did not differ in patients with ongoing pregnancy regardless of serum P levels being above/below 8.8 ng/ml. LIMITATIONS, REASONS FOR CAUTION: Only women with MVP were included. Extrapolation to other P administration forms needs to be validated. WIDER IMPLICATIONS OF THE FINDINGS: This study identified the threshold of serum P as 8.8 ng/ml on the day of ET for artificial endometrial preparation cycles necessary to optimize outcomes, in cycles with own or donated oocytes. One-third of patients receiving MVP show inadequate levels of serum P that, in turn, impact the success of the ART cycle. Monitoring P levels in the mid-luteal phase is recommended when using MVP to adjust the doses according to the needs of the patient. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: NCT03272412.

Novel and conventional embryo parameters as input data for artificial neural networks: an artificial intelligence model applied for prediction of the implantation potential.

OBJECTIVE: To describe novel embryo features capable of predicting implantation potential as input data for an artificial neural network (ANN) model. DESIGN: Retrospective cohort study. SETTING: University-affiliated private IVF center. PATIENT(S): This study included 637 patients from the oocyte donation program who underwent single-blastocyst transfer during two consecutive years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The research was divided into two phases. Phase 1 consisted of the description and analysis of the following embryo features in implanted and nonimplanted embryos: distance and speed of pronuclear migration, blastocyst expanded diameter, inner cell mass area, and trophectoderm cell cycle length. Phase 2 consisted of the development of an ANN algorithm for implantation prediction. Results were obtained for four models fed with different input data. The predictive power was measured with the use of the area under the receiver operating characteristic curve (AUC). RESULT(S): Out of the five novel described parameters, blastocyst expanded diameter and trophectoderm cell cycle length had statistically different values in implanted and nonimplanted embryos. After the ANN models were trained and validated using fivefold cross-validation, they were capable of predicting implantation on testing data with AUCs of 0.64 for ANN1 (conventional morphokinetics), 0.73 for ANN2 (novel morphodynamics), 0.77 for ANN3 (conventional morphokinetics + novel morphodynamics), and 0.68 for ANN4 (discriminatory variables from statistical test). CONCLUSION(S): The novel proposed embryo features affect the implantation potential, and their combination with conventional morphokinetic parameters is effective as input data for a predictive model based on artificial intelligence.

The influence of oxygen concentration during embryo culture on obstetric and neonatal outcomes: a secondary analysis of a randomized controlled trial.

STUDY QUESTION: Does oxygen concentration during 3-day embryo culture affect obstetric and neonatal outcomes? SUMMARY ANSWER: Oxygen concentration during 3-day embryo culture does not seem to affect the obstetric and neonatal outcomes measured. WHAT IS KNOWN ALREADY: Atmospheric oxygen appears to be harmful during extended embryo culture. Embryo culture conditions might therefore be a potential risk factor for subsequent fetal development and the health of future children. No data are available concerning the obstetrics and neonatal outcomes after Day 3 transfer of embryos cultured under reduced and atmospheric oxygen tensions. STUDY DESIGN, SIZE, DURATION: A secondary analysis of a previous randomized controlled trial assessing clinical pregnancy outcomes was carried out. This analysis included 1125 consecutive oocyte donation cycles utilizing ICSI or IVF and Day 3 embryo transfers between November 2009 and April 2012. The whole cohort of donated oocytes from patients who agreed to participate in the study were randomly allocated (1:1 ratio) to a reduced O2 tension group (6% O2) or an air-exposed group (20% O2) based on a computer-generated randomization list. Fresh and vitrified oocytes were used for oocyte donation. Only those pregnancies with a live birth at or beyond 24 weeks of gestation were included. PARTICIPANTS/MATERIALS, SETTING, METHODS: Day 3 embryos were cultured in an atmosphere of 5.5% CO2, 6% O2, 88.5% N2 versus a dual gas system in air. MAIN RESULTS AND THE ROLE OF CHANCE: From the eligible 1125 cycles, 564 were allocated to the 6% O2 group and 561 cycles to the 20% O2 group. However, 50 and 62 cycles did not reach embryo transfer in the 6% and 20% O2 groups, respectively. No differences were found between 6% O2 and atmospheric O2 tension in the number of livebirths per embryo transfer (mean ± SD, 0.5 ± 0.7 versus 0.5 ± 0.7), pregnancy complications or neonatal outcomes. Both groups (6% and atmospheric O2) had similar single and twin delivery rates (40.8% versus 38.1% and 10.7% versus 12.3%, respectively). Preterm delivery rates and very preterm delivery rates (10.80% versus 13.24% and 1.25% versus 2.94%, respectively), birthweight (3229 ± 561 g versus 3154 ± 731 g), low birthweight (2.92% versus 2.45%), birth height (50.18 ± 2.41 cm versus 49.7 ± 3.59 cm), head circumference (34.16 ± 1.87 cm versus 33.09 ± 1.85 cm) and 1 min Apgar scores (8.96 ± 0.87 versus 8.89 ± 0.96) were also similar between 6% and atmospheric O2 groups, respectively. LIMITATIONS, REASONS FOR CAUTION: The number of liveborns finally analyzed is still small and not all obstetric and neonatal variables could be evaluated. Furthermore, a small proportion of the obstetric and neonatal data was obtained through a questionnaire filled out by the patients themselves. One reason for the lack of effect of oxygen concentration on pregnancy outcome could be the absence of trophectoderm cells at cleavage stage, which may make Day 3 embryos less susceptible to hypoxic conditions. WIDER IMPLICATIONS OF THE FINDINGS: Nowadays many IVF laboratories use a more physiological oxygen concentration for embryo culture. However, the benefits of using low oxygen concentration on both laboratory and clinical outcomes during embryo culture are still under debate. Furthermore, long-term studies investigating the effect of using atmospheric O2 are also needed. Gathering these type of clinical data is indeed, quite relevant from the safety perspective. The present data show that, at least in egg donation cycles undergoing Day 3 embryo transfers, culturing embryos under atmospheric oxygen concentration seems not to affect perinatal outcomes. STUDY FUNDING/COMPETING INTEREST(S): The present project was supported by the R + D program of the Regional Valencian Government, Spain (IMPIVA IMDTF/2011/214). The authors declare that they have no conflict of interest with respect to the content of this manuscript. TRIAL REGISTRATION NUMBER: NCT01532193.

Oocyte vitrification for fertility preservation in women with endometriosis: an observational study.

OBJECTIVE: To describe the outcome of fertility preservation (FP) using vitrified oocytes in patients with endometriosis and to determine the impact of ovarian surgery. DESIGN: Retrospective observational study. SETTING: University-affiliated private in vitro fertilization (IVF) center. PATIENT(S): Four hundred and eighty-five women with endometriosis who underwent FP from January 2007 to July 2018. INTERVENTION(S): Vitrification of metaphase II (MII) oocytes for future use. MAIN OUTCOME MEASURE(S): Oocyte survival rate and cumulative live-birth rate (CLBR). RESULT(S): Mean age at vitrification was 35.7 ± 3.7 years. The women undergoing operations were younger than the nonsurgical patients (33.4 ± 3.6 years vs. 36.7 ± 3.7 years). The survival rate and CLBR were 83.2% and 46.4%, respectively. The number of vitrified oocytes per cycle (6.2 ± 5.8) was higher for the nonsurgical patients compared with the unilateral (5.0 ± 4.5) or bilateral (4.5 ± 4.4) surgery groups, but was comparable among the surgical patients. The effect of age (adjusted odds ratio [OR] 0.904; 95% CI, 0.858-0.952), number of oocytes (adjusted OR 1.050; 95% CI, 1.025-1.091), and survival (adjusted OR 1.011; 95% CI, 1.001-1.020) on the CLBR was confirmed. However, the effect of surgery was not observed (adjusted OR 1.142; 95% CI, 0.778-1.677). Nonetheless, the ovarian response (vitrified oocytes = 8.6 ± 6.9 vs. 5.1 ± 4.8) and CLBR (72.5% vs. 52.8%) were higher in young (≤35 years) nonsurgical patient versus the surgical patients; older women showed similar outcomes. CONCLUSION(S): Fertility preservation gives patients with endometriosis a valid treatment option to help them increase their reproductive chances. We suggest performing surgery after ovarian stimulation for FP in young women. In older women, an individualized treatment should be considered.

Cervical pregnancy in assisted reproduction: an analysis of risk factors in 91,067 ongoing pregnancies.

RESEARCH QUESTION: What is the frequency of cervical pregnancy in women undergoing assisted reproductive technologies (ART) and what are the risk factors? DESIGN: Case-control study of women undergoing assisted reproductive technology (ART) at 25 private assisted reproduction clinics run by the same group in Spain. Two control groups (tubal ectopic pregnancies and intrauterine pregnancies) were established. The main outcome measure was frequency of cervical pregnancy. Demographic, clinical factors and IVF parameters were assessed for their influence on cervical pregnancy risk. RESULTS: Thirty-two clinical pregnancies were achieved out of 91,067 ongoing pregnancies, yielding a rate of 3.5/10,000. Cervical pregnancies represented 2.02% of all ectopic pregnancies (32/1582). The main risk factors two or more previous pregnancies (OR 2.68; CI 1.18 to 6.07); two or more previous miscarriages (OR 4.21; CI1.7 to 10.43), one or more previous curettages (OR 3.99, CI 1.67 to 9.56), two or more previous curettages (OR 4.71; CI 1.19 to 18.66) and smoking (OR 2.82 CI 1.14 to 6.94). History of caesarean sections and tubal pregnancy was not associated with an elevated cervical pregnancy risk. Infertility conditions and endometrial thickness were similar across the three groups. The proportion of women from whom fewer than 10 oocytes were retrieved was higher in the clinical pregnancy group than in the IUP group. CONCLUSIONS: In ART, the main risk factors for cervical ectopic pregnancy are a history of at least two pregnancies, miscarriages, at least one curettage and smoking. IVF parameters do not seem to influence the development of clinical pregnancies. Cervical pregnancies are less common in ART than previously reported, attributable to improvements in ART; a publication bias in early IVF reports cannot be ruled out.

Time of morulation and trophectoderm quality are predictors of a live birth after euploid blastocyst transfer: a multicenter study.

OBJECTIVE: To investigate whether the morphodynamic characterization of a euploid blastocyst's development allows a higher prediction of a live birth after single-embryo-transfer (SET). DESIGN: Observational cohort study conducted in two phases: training and validation. SETTING: Private in vitro fertilization centers. PATIENT(S): Euploid blastocysts: 511 and 319 first vitrified-warmed SETs from 868 and 546 patients undergoing preimplantation genetic testing for aneuploidies (PGT-A) in the training and validation phase, respectively. INTERVENTION(S): Data collected from time of polar body extrusion to time of starting blastulation, and trophectoderm and inner-cell-mass static morphology in all embryos cultured in a specific time-lapse incubator with a continuous medium. Logistic regressions conducted to outline the variables showing a statistically significant association with live birth. In the validation phase, these variables were tested in an independent data set. MAIN OUTCOME MEASURE(S): Live births per SET. RESULT(S): The average live birth rate (LBR) in the training set was 40% (N = 207/511). Only time of morulation (tM) and trophectoderm quality were outlined as putative predictors of live birth at two IVF centers. In the validation set, the euploid blastocysts characterized by tM <80 hours and high-quality trophectoderm resulted in a LBR of 55.2% (n = 37/67), while those with tM ≥ 80 hours and a low-quality trophectoderm resulted in a LBR of 25.5% (N = 13/51). CONCLUSION(S): Time of morulation and trophectoderm quality are better predictors of a euploid blastocyst's reproductive competence. Our evidence was reproducible across different centers under specific culture conditions. These data support the crucial role of morulation for embryo development, a stage that involves massive morphologic, cellular, and molecular changes and deserves more investigation.