Delta and kappa opioid receptors in human endometrium during the menstrual cycle: Expression and localization

Objective Endogenous opioid peptides were reported to be involved in the regulation of reproductive physiology and their precursors and receptors were described in many of the male and female reproductive tissues. Mu opioid receptor (MOR) was described in human endometrial cells and its expression and localization changed during the menstrual cycle. However, there is no data from the distribution of the other opioid receptors: Delta (DOR) and Kappa (KOR). The objective of the present work was to analyze the dynamics of expression and localization of DOR and KOR in human endometrium throughout the menstrual cycle. Study design Human endometrial samples from different menstrual cycle phases were analyzed by immunohistochemistry. Results DOR and KOR were present in all samples analyzed and the protein expression and localization changed throughout the menstrual cycle. Both receptor expression increased during the late proliferative phase and decreased during the late secretory-one, especially in the luminal epithelium. DOR expression was generally higher than KOR expression in all cell compartments. Conclusions The presence of DOR and KOR in human endometrium and their dynamic changes during the menstrual cycle join the results previously obtained in MOR suggesting a possible role of opioids in reproduction events related to the human endometrium.The authors thank Leire Andrés (Cruces University Hospital) and Edurne Alonso (UPV/EHU) for help in the discussion on endometrial histology. This work received financial support from the University of the Basque Country (Grant PPGA19/04). E.O. carried out all the experimentation without any public or private financial help. L.T. acknowledges the financial support given by University of the Basque Country (PIF15/149). The authors also thank Ane Portillo for technical help in analysing the results

Meta-Analysis of the Embryo Freezing Transfer Interval

Background The decision of whether frozen embryo transfer (FET) should be performed in the cycle immediately after OPU or at least one cycle later is controversial. FET could improve pregnancy rates in IVF; however, how much time is needed for the endometrium to return to optimal receptivity after ovarian stimulation is not known. Methods Electronic search in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials to identify studies providing data on the influence of the interval between embryo freezing (or OPU) and FET in FET cycles published between January 1, 2007, and February 1, 2020. Main findings Data analyzed indicated that in the immediate FET cycles, there was a trend to an increased biochemical pregnancy rate (RR = 1.08; CI = 1.00-1.18), whereas the clinical pregnancy rate was somewhat higher, but without reaching statistical significance (RR = 1.07; CI = 0.99-1.15). The live birth rate was similar in the two groups (RR = 1.05; CI = 0.95-1.15), as was the implantation rate (RR = 0.98; CI = 0.83-1.16). Stratifying by embryo stage or FET type (freeze-all or FET after failed fresh transfer) showed no differences. Conclusion Systematically delaying FET does not offer benefits to IVF outcomes. In addition, immediate transfer is associated with a nonsignificant trend to better clinical pregnancy rate and it also avoids the psychological effects of prolonging the stress on prospective parents

Aspiration of excess follicles before intrauterine insemination in high response cycles

Purpose To assess the outcome of excess follicle aspiration before intrauterine insemination (EFABI) in intrauterine insemination (IUI) cycles with 4-6 follicles >= 14 mm. Methods A retrospective case-control study with 1559 patients undergoing IUI (donor and husband's sperm), of whom 86 underwent EFABI. We studied also an historical series of 2213 patients before EFABI implementation. For 3.5 years, all women undergoing IUI developing 4-6 follicles >= 14 mm were offered EFABI on the day of hCG administration. Pregnancy rates (PRs), multiple PRs, and adverse effects were measured. Results EFABI was associated with a similar multiple PR (17.8% vs 17.5% in non-EFABI cases), with no triplets in EFABI patients. Live birth rates were significantly higher in EFABI cycles in IUI overall (25.5% vs 15.2%). When considered separately, the performance of EFABI resulted in significantly increased live birth rates in IUI-donor cycles (32.5% vs 18.5%), whereas the differences in IUI-husband cycles (19.5% vs 12.9%) did not reach statistical significance. The PR was 21.2% during the EFABI implementation period and 19.4% in the pre-EFABI period. Conclusions EFABI in cycles in which 4-6 follicles reach >= 14 mm is a simple option that reduces cycle cancellation rates, results in higher PRs than cycles with 1-3 follicles, and lowers the risk of multiple pregnancy

Antibacterial and antifungal activity of the human endometrial fluid during the natural cycle

[EN] Purpose. Some microbiota patterns have been associated with favorable IVF prognosis and others with pathological conditions. The endometrial fluid aspirate (EFA) contains antibacterial proteins that are enriched in implantative IVF cycles, but the antimicrobial effect of EFA has not been addressed. We aimed to evaluate the antimicrobial activity of the human endometrial fluid during the natural cycle. Methods. EFA was obtained through an embryo transfer catheter in 38 women, aged 18-40 years, with regular cycles attending to a fertility clinic. The antimicrobial activity of EFAs was tested against two strains of Staphylococcus aureus; one strain each of Streptococcus agalactiae, Enterococcus faecalis, Escherichia coli, and Klebsiella pneumoniae; and three yeasts (Candida albicans, Candida glabrata, and Candida krusei). Results. All samples exhibited antibacterial activity against S. aureus. In addition, 32.4% of EFAs were active against one of the other microorganisms assayed, 16.2% against two, and 5.4% against four of them. In contrast, none exhibited antibacterial activity against E. coli or K. pneumoniae. The antimicrobial activity differs considerably between EFA samples, and we failed to observe a cycle-related pattern. Conclusions. EFA presented two antimicrobial activity patterns: (a) one common to all the samples, exhibiting activity against S. aureus and lack of activity against E. coli and K. pneumoniae, and (b) an individualized pattern, showing activity against some of the other microorganisms tested. The intensity of antibacterial activity differs between EFA samples. Our data suggest that the uterine microbiota is controlled by means of endometrial fluid components.This study was partially supported by a Grant for Fertility Innovation (GFI, 2011) from Merck, Darmstadt, Germany. M. Bregón-Villahoz is recipient of a predoctoral grant from the Universidad del País Vasco-Euskal Herriko Unibertsitatea (UPV/EHU) (PIF19/316). The authors thank the technical and human support provided by DNA Bank Service (SGIker) of the University of the Basque Country (UPV/EHU) and European funding (ERDF and ESF). CIC bioGUNE is accredited with the Severo Ochoa Excellence award by the Spanish Ministerio de Economía y Competitividad, MINECO (SEV-2016-0644)

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

OBJECTIVE: To assess the frequency of cervical pregnancy (CP) in women undergoing assisted reproductive techniques (ART) and to ascertain its risk factors DESIGN: Case-control study. Two control groups were established: tubal ectopic pregnancies and intrauterine pregnancies. SETTING: 25 private assisted reproduction clinics run by the same group in Spain PATIENT(S): Women undergoing ART (artificial insemination, or IVF with own or donor oocytes). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Frequency of CP. Ascertainment of demographic and clinical risk factors. Assessment of the influence of IVF parameters on CP risk. RESULT(S): There were 32 CPs out of 91,067 ongoing pregnancies, yielding a rate of 3.5/10,000. CPs represented 2.02% of all ectopic pregnancies (32/1582). The main risk factors were: ≥ 2 previous pregnancies (OR= 2.68; CI=1.18-6.07), ≥2 previous miscarriages (OR= 4.21, CI=1.7- 10.43), ≥ 2 previous curettages (OR=4.71; CI= (1.19-18.66) and smoking (OR= 2.82 (1.14-6.94). History of cesarean sections and tubal pregnancy were not associated with an elevated CP risk. Infertility conditions and endometrial thickness were similar across the three groups. The proportion of women from whom < 10 oocytes were retrieved was higher in the CP group than in either of the control groups. CONCLUSION(S): In ART, the main risk factors for ectopic pregnancy are a history of at least 2 pregnancies/miscarriages/curettages, and smoking. IVF parameters do not seem to influence the development of CP. CP is less common in ART than previously reported, likely attributable to improvements in ART, although a publication bias cannot be ruled out in early IVF reports

Effect of vitamin E administered to men in infertile couples on sperm and assisted reproduction outcomes: a double-blind randomized study

Objective: To evaluate the influence on sperm parameters and invitro fertilization (IVF) outcomes of the administration of 400 mg/day of vitamin E for 3 months to men from infertile couples who are undergoing IVF. Design: Double-blind, placebo-controlled, randomized study. Setting: Human reproduction unit of a university hospital. Patients: A total of 101 couples, 50 in the vitamin E group and 51 in the placebo group, undergoing IVF, among whom 64.4% of cases had an abnormal spermiogram according to World Health Organization (WHO) criteria. Interventions: Vitamin E (alpha-tocopherol), 400 mg daily by mouth for 3 months, with sperm analysis performed immediately before starting the treatment and 3 months later on the day of IVF. Main Outcome Measures: WHO sperm parameters and IVF outcomes. Results: Although there was a statistically significant increase in progressive motility in the vitamin E group compared with before-treatment values, a similar increase occurred in the placebo group. Normal morphology was even better in the placebo group. Regarding IVF outcomes, better fertilization rates were observed in the placebo group, but the live-birth rate per transfer was statistically significantly higher in the vitamin E group: 17 (41.46%) of 41 versus 9 (20.46%) of 44 in the placebo group. Although the clinical pregnancy rates (both per transfer and per cycle started) and the implantation rate were somewhat higher in the vitamin E group (43.9% and 25%; 36.0% and 22.0%; and 24.7% and 14.1%, respectively), the increase was not statistically significant. Conclusions: The effect of vitamin E on classic sperm parameters was not an improvement over placebo. Nonetheless, vitamin E administration was associated with a statistically significantly higher live-birth rate, and there was a trend toward better results in other IVF parameters

Estimation of preterm labor immediacy by nonlinear methods

Preterm delivery affects about one tenth of human births and is associated with an increased perinatal morbimortality as well as with remarkable costs. Even if there are a number of predictors and markers of preterm delivery, none of them has a high accuracy. In order to find quantitative indicators of the immediacy of labor, 142 cardiotocographies (CTG) recorded from women consulting because of suspected threatened premature delivery with gestational ages comprehended between 24 and 35 weeks were collected and analyzed. These 142 samples were divided into two groups: the delayed labor group (n = 75), formed by the women who delivered more than seven days after the tocography was performed, and the anticipated labor group (n = 67), which corresponded to the women whose labor took place during the seven days following the recording. As a means of finding significant differences between the two groups, some key informational properties were analyzed by applying nonlinear techniques on the tocography recordings. Both the regularity and the persistence levels of the delayed labor group, which were measured by Approximate Entropy (ApEn) and Generalized Hurst Exponent (GHE) respectively, were found to be significantly different from the anticipated labor group. As delivery approached, the values of ApEn tended to increase while the values of GHE tended to decrease, suggesting that these two methods are sensitive to labor immediacy. On this paper, for the first time, we have been able to estimate childbirth immediacy by applying nonlinear methods on tocographies. We propose the use of the techniques herein described as new quantitative diagnosis tools for premature birth that significantly improve the current protocols for preterm labor prediction worldwide.Work by the first author was supported by the Basque Government grant PRE-2015-1-194,and work by the first and second authors by the Basque Government grant IT974-16. This work was also supported in part by FERRING laboratories Madrid, Spain (RM), https://www.ferring.com/en/home/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

microRNA-based signatures obtained from endometrial fluid identify implantative endometrium

STUDY QUESTION Is it possible to use free and extracellular vesicle-associated microRNAs (miRNAs) from human endometrial fluid (EF) samples as non-invasive biomarkers for implantative endometrium? SUMMARY ANSWER The free and extracellular vesicle-associated miRNAs can be used to detect implantative endometrium in a non-invasive manner. WHAT IS KNOWN ALREADY miRNAs and extracellular vesicles (EVs) from EF have been described as mediators of the embryo-endometrium crosstalk. Therefore, the analysis of miRNA from this fluid could become a non-invasive technique for recognizing implantative endometrium. This analysis could potentially help improve the implantation rates in ART. STUDY DESIGN, SIZE, DURATION In this prospective study, we first optimized different protocols for EVs and miRNA analyses using the EF of a setup cohort (n = 72). Then, we examined differentially expressed miRNAs in the EF of women with successful embryo implantation (discovery cohort n = 15/validation cohort n = 30) in comparison with those for whom the implantation had failed (discovery cohort n = 15/validation cohort n = 30). Successful embryo implantation was considered when pregnancy was confirmed by vaginal ultrasound showing a gestational sac 4 weeks after embryo transfer (ET). PARTICIPANTS/MATERIALS, SETTING, METHODS The EF of the setup cohort was obtained before starting fertility treatment during the natural cycle, 16-21 days after the beginning of menstruation. For the discovery and validation cohorts, the EF was collected from women undergoing frozen ET on Day 5, and the samples were collected immediately before ET. In this study, we compared five different methods; two of them based on direct extraction of RNA and the other three with an EV enrichment step before the RNA extraction. Small RNA sequencing was performed to determine the most efficient method and find a predictive model differentiating between implantative and non-implantative endometrium. The models were confirmed using quantitative PCR in two sets of samples (discovery and validation cohorts) with different implantation outcomes. MAIN RESULTS AND THE ROLE OF CHANCE The protocols using EV enrichment detected more miRNAs than the methods based on direct RNA extraction. The two most efficient protocols (using polymer-based precipitation (PBP): PBP-M and PBP-N) were used to obtain two predictive models (based on three miRNAs) allowing us to distinguish between an implantative and non-implantative endometrium. The first Model 1 (PBP-M) (discovery: AUC = 0.93; P-value = 0.003; validation: AUC = 0.69; P-value = 0.019) used hsa-miR-200b-3p, hsa-miR-24-3p and hsa-miR-148b-3p. Model 2 (PBP-N) (discovery: AUC = 0.92; P-value = 0.0002; validation: AUC = 0.78; P-value = 0.0002) used hsa-miR-200b-3p, hsa-miR-24-3p and hsa-miR-99b-5p. Functional analysis of these miRNAs showed strong association with key implantation processes such as in utero embryonic development or transforming growth factor-beta signaling. LARGE SCALE DATA The FASTQ data are available in the GEO database (access number GSE178917). LIMITATIONS, REASONS FOR CAUTION One important factor to consider is the inherent variability among the women involved in the trial and among the transferred embryos. The embryos were pre-selected based on morphology, but neither genetic nor molecular studies were conducted, which would have improved the accuracy of our tests. In addition, a limitation in miRNA library construction is the low amount of input RNA. WIDER IMPLICATIONS OF THE FINDINGS We describe new non-invasive protocols to analyze miRNAs from small volumes of EF. These protocols could be implemented in clinical practice to assess the status of the endometrium before attempting ET. Such evaluation could help to avoid the loss of embryos transferred to a non-implantative endometrium. STUDY FUNDING/COMPETING INTEREST(S) J.I.-P. was supported by a predoctoral grant from the Basque Government (PRE_2017_0204). This study was partially funded by the Grant for Fertility Innovation (GFI, 2011) from Merck (Darmstadt, Germany). It was also supported by the Spanish Ministry of Economy and Competitiveness MINECO within the National Plan RTI2018-094969-B-I00, the European Union's Horizon 2020 research and innovation program (860303), the Severo Ochoa Centre of Excellence Innovative Research Grant (SEV-2016-0644) and the Instituto de Salud Carlos III (PI20/01131). The funding entities did not play any role in the study design, collection, analysis and interpretation of data, writing of the report or the decision to submit the article for publication. The authors declare no competing interests.J.I.-P. was supported by a predoctoral grant from the Basque Government (PRE_2017_0204). This study was partially funded by the Grant for Fertility Innovation (GFI, 2011) from Merck (Darmstadt, Germany). The project was also supported by the Spanish Ministry of Economy and Competitiveness MINECO within the national plan RTI2018-094969-B-I00, the European Union's Horizon 2020 research and innovation program (860303), the Severo Ochoa Centre of Excellence Innovative Research Grant (SEV-2016-0644) and the Instituto de Salud Carlos III (PI20/01131). The funding entities did not have any role in study design, sample collection, analysis and interpretation of data, report writing or decision to submit the article for publication

Colonización materna por streptococus del grupo B (SGB), profilaxis de la serpis neonatal: tesis doctoral

Tesis doctoral original leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Obstetricia y Ginecología. Fecha de lectura: 14 de mayo de 198