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The World Journal of Men's Health Jul 2022Oocytes and spermatozoa are electrogenic cells with the ability to respond to electrical stimuli and modulate their electrical properties accordingly. Determination of...
PURPOSE
Oocytes and spermatozoa are electrogenic cells with the ability to respond to electrical stimuli and modulate their electrical properties accordingly. Determination of the ionic events during the gamete maturation helps to design suitable culture media for gametes in assisted reproductive technology (ART). The present systematic review focuses on the electrophysiology of human gametes during different stages of maturation and also during fertilization.
MATERIALS AND METHODS
The reports published in the English language between January 2000 and July 2021 were extracted from various electronic scientific databases following the PRISMA checklist using specific MeSH keywords.
RESULTS
Subsequent to the screening process with defined inclusion and exclusion criteria, 60 articles have been included in this review. Among them, 11 articles were directly related to the electrophysiology of human oocytes and 49 physiology department to the electrophysiology of human spermatozoa.
CONCLUSIONS
Gametes generate electrical currents by ionic exchange, particularly Na, K, Cl, H, Zn, Cu, Se, Mg, HCO, and Ca through specific ion channels in different stages of gamete maturation. The ionic concentrations, pH, and other physicochemical variables are modulated during the gametogenesis, maturation, activation, and the fertilization process following gamete function and metabolism. The electrical properties of human gametes change during different stages of maturation. Although it is demonstrated that the electrical properties are significant regulators of cell signaling and are fundamental to gamete maturation and fertilization, their exact roles in these processes are still poorly understood. Further research is required to unveil the intricate electrophysiological processes of human gamete maturation.
PubMed: 35021309
DOI: 10.5534/wjmh.210107 -
Journal of Assisted Reproduction and... Jul 2018Mammalian oogenesis and folliculogenesis share a dynamic connection that is critical for gamete development. For maintenance of quiescence or follicular activation,... (Review)
Review
PURPOSE
Mammalian oogenesis and folliculogenesis share a dynamic connection that is critical for gamete development. For maintenance of quiescence or follicular activation, follicles must respond to soluble signals (growth factors and hormones) and physical stresses, including mechanical forces and osmotic shifts. Likewise, mechanical processes are involved in cortical tension and cell polarity in oocytes. Our objective was to examine the contribution and influence of biomechanical signaling in female mammalian gametogenesis.
METHODS
We performed a systematic review to assess and summarize the effects of mechanical signaling and mechanotransduction in oocyte maturation and folliculogenesis and to explore possible clinical applications. The review identified 2568 publications of which 122 met the inclusion criteria.
RESULTS
The integration of mechanical and cell signaling pathways in gametogenesis is complex. Follicular activation or quiescence are influenced by mechanical signaling through the Hippo and Akt pathways involving the yes-associated protein (YAP), transcriptional coactivator with PDZ-binding motif (TAZ), phosphatase and tensin homolog deleted from chromosome 10 (PTEN) gene, the mammalian target of rapamycin (mTOR), and forkhead box O3 (FOXO3) gene.
CONCLUSIONS
There is overwhelming evidence that mechanical signaling plays a crucial role in development of the ovary, follicle, and oocyte throughout gametogenesis. Emerging data suggest the complexities of mechanotransduction and the biomechanics of oocytes and follicles are integral to understanding of primary ovarian insufficiency, ovarian aging, polycystic ovary syndrome, and applications of fertility preservation.
Topics: Animals; Female; Humans; Mechanotransduction, Cellular; Oocytes; Oogenesis; Ovarian Follicle; Ovary; Signal Transduction
PubMed: 29691711
DOI: 10.1007/s10815-018-1180-y -
Reproductive Biology and Endocrinology... Sep 2021Sequential embryo transfer has been proposed as a way to improve embryo implantation in women for in vitro fertilization (IVF), but the effect on pregnancy outcomes...
BACKGROUND
Sequential embryo transfer has been proposed as a way to improve embryo implantation in women for in vitro fertilization (IVF), but the effect on pregnancy outcomes remains ambiguous. This systematic review was conducted to investigate the efficacy of sequential embryo transfer on IVF outcomes.
METHODS
A literature search was performed in the PubMed, Web of Science, Cochrane Library, ScienceDirect and Wanfang databases. Data were pooled using a random- or fixed-effects model according to study heterogeneity. The results are expressed as relative risks (RRs) with 95% confidence intervals (CIs). Heterogeneity was evaluated by the I statistic. The study protocol was registered prospectively on INPLASY, ID: INPLASY202180019.
RESULTS
Ten eligible studies with 2658 participants compared sequential embryo transfer and cleavage transfer, while four studies with 513 participants compared sequential embryo transfer and blastocyst transfer. The synthesis results showed that the clinical pregnancy rate was higher in the sequential embryo transfer group than in the cleavage embryo transfer group (RR 1.42, 95% CI 1.26-1.60, P< 0.01) for both women who did experience repeated implantation failure (RIF) (RR 1.58, 95% CI 1.17-2.13, P< 0.01) and did not experience RIF (Non-RIF) (RR 1.44, 95% CI 1.20-1.66, P< 0.01). However, sequential embryo transfer showed no significant benefit over blastocyst embryo transfer.
CONCLUSION
The current systematic review demonstrates that sequential cleavage and blastocyst embryo transfer improve the clinical pregnancy rate over conventional cleavage embryo transfer. For women with adequate embryos, sequential transfer could be attempted following careful consideration. More high-grade evidence from prospective randomized studies is warranted.
Topics: Blastocyst; Cleavage Stage, Ovum; Embryo Transfer; Embryo, Mammalian; Female; Fertilization in Vitro; Humans; Infertility; Pregnancy; Pregnancy Outcome; Pregnancy Rate; Treatment Outcome
PubMed: 34521412
DOI: 10.1186/s12958-021-00824-y -
Journal of Assisted Reproduction and... Aug 2016The purpose of this study was to evaluate whether outcomes are different if controlled ovarian stimulation (COS) is started in the luteal phase rather than the... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The purpose of this study was to evaluate whether outcomes are different if controlled ovarian stimulation (COS) is started in the luteal phase rather than the follicular phase.
METHODS
A systematic review and meta-analysis was performed. Sixteen studies were included in the qualitative analysis, and eight studies with a total of 338 women were included in the quantitative analysis.
RESULTS
Cycles initiated in the luteal phase were slightly longer (WMD 1.1 days, 95 % CI 0.39-1.9) and utilized more total gonadotropins (WMD 817 IU, 95 % CI 489-1144). However, no differences were noted in peak estradiol levels (WMD -411 pg/ml, 95 % CI -906-84.7) or in the total number of oocytes retrieved (WMD 0.52 oocytes, 95 % CI -0.74-1.7). There were slightly more mature oocytes retrieved in the luteal phase (WMD 0.77 oocytes, 95 % CI 0.21-1.3), and fertilization rates were significantly higher (WMD 10 %, 95 % CI 0.03-0.18). While only three studies reported pregnancy outcomes, no difference was noted in the FET pregnancy rates after COS in the luteal versus follicular phase (RR 0.95, 95 % CI 0.56-1.7). A post hoc power analysis revealed that a sample of this size was sufficient to detect a clinically meaningful difference of 2 oocytes retrieved with 93 % power.
CONCLUSION
Although initiating COS in the luteal phase requires a longer stimulation and a higher dose of total gonadotropin, these differences are not clinically significant. Furthermore, COS initiated in the luteal phase does not compromise the quantity or quality of oocytes retrieved compared to outcomes of traditional stimulation in the follicular phase.
Topics: Adult; Cryopreservation; Female; Fertility Preservation; Fertilization in Vitro; Follicular Phase; Humans; Luteal Phase; Menstrual Cycle; Neoplasms; Oocyte Retrieval; Oocytes; Ovulation Induction; Pregnancy; Pregnancy Outcome
PubMed: 27146151
DOI: 10.1007/s10815-016-0721-5 -
The Cochrane Database of Systematic... Jan 2017Ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology (ART) cycles is a treatment-induced disease that has an estimated prevalence of 20% to 33%... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology (ART) cycles is a treatment-induced disease that has an estimated prevalence of 20% to 33% in its mild form and 3% to 8% in its moderate or severe form. These numbers might even be higher for high-risk women such as those with polycystic ovaries or a high oocyte yield from ovum pickup.
OBJECTIVES
The objective of this overview is to identify and summarise all evidence from Cochrane systematic reviews on interventions for prevention or treatment of moderate, severe and overall OHSS in couples with subfertility who are undergoing ART cycles.
METHODS
Published Cochrane systematic reviews reporting on moderate, severe or overall OHSS as an outcome in ART cycles were eligible for inclusion in this overview. We also identified Cochrane submitted protocols and title registrations for future inclusion in the overview. The evidence is current to 12 December 2016. We identified reviews, protocols and titles by searching the Cochrane Gynaecology and Fertility Group Database of Systematic Reviews and Archie (the Cochrane information management system) in July 2016 on the effectiveness of interventions for outcomes of moderate, severe and overall OHSS. We undertook in duplicate selection of systematic reviews, data extraction and quality assessment. We used the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool to assess the quality of included reviews, and we used GRADE methods to assess the quality of the evidence for each outcome. We summarised the characteristics of included reviews in the text and in additional tables.
MAIN RESULTS
We included a total of 27 reviews in this overview. The reviews were generally of high quality according to AMSTAR ratings, and included studies provided evidence that ranged from very low to high in quality. Ten reviews had not been updated in the past three years. Seven reviews described interventions that provided a beneficial effect in reducing OHSS rates, and we categorised one additional review as 'promising'. Of the effective interventions, all except one had no detrimental effect on pregnancy outcomes. Evidence of at least moderate quality indicates that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Metformin treatment before and during an ART cycle for women with PCOS (moderate-quality evidence).• Gonadotrophin-releasing hormone (GnRH) antagonist protocol in ART cycles (moderate-quality evidence).• GnRH agonist (GnRHa) trigger in donor oocyte or 'freeze-all' programmes (moderate-quality evidence). Evidence of low or very low quality suggests that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Clomiphene citrate for controlled ovarian stimulation in ART cycles (low-quality evidence).• Cabergoline around the time of human chorionic gonadotrophin (hCG) administration or oocyte pickup in ART cycles (low-quality evidence).• Intravenous fluids (plasma expanders) around the time of hCG administration or oocyte pickup in ART cycles (very low-quality evidence).• Progesterone for luteal phase support in ART cycles (low-quality evidence).• Coasting (withholding gonadotrophins) - a promising intervention that needs to be researched further for reduction of OHSS.On the basis of this overview, we must conclude that evidence is currently insufficient to support the widespread practice of embryo cryopreservation.
AUTHORS' CONCLUSIONS
Currently, 27 reviews in the Cochrane Library were conducted to report on or to try to report on OHSS in ART cycles. We identified four review protocols but no new registered titles that can potentially be included in this overview in the future. This overview provides the most up-to-date evidence on prevention of OHSS in ART cycles from all currently published Cochrane reviews on ART. Clinicians can use the evidence summarised in this overview to choose the best treatment regimen for individual patients - a regimen that not only reduces the chance of developing OHSS but does not compromise other outcomes such as pregnancy or live birth rate. Review results, however, are limited by the lack of recent primary studies or updated reviews. Furthermore, this overview can be used by policymakers in developing local and regional protocols or guidelines and can reveal knowledge gaps for future research.
Topics: Cabergoline; Ergolines; Female; Gonadotropin-Releasing Hormone; Humans; Metformin; Ovarian Hyperstimulation Syndrome; Pregnancy; Progesterone; Reproductive Techniques, Assisted; Review Literature as Topic
PubMed: 28111738
DOI: 10.1002/14651858.CD012103.pub2 -
Ultrasound in Obstetrics & Gynecology :... May 2017Blastocyst transfer in assisted reproduction techniques could be advantageous because the timing of exposure of the embryo to the uterine environment is more analogous... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Blastocyst transfer in assisted reproduction techniques could be advantageous because the timing of exposure of the embryo to the uterine environment is more analogous to a natural cycle and permits embryo self-selection after activation of the embryonic genome on day 3. Conversely, the in-vitro environment is likely to be inferior to that in vivo, and in-vitro culture beyond embryonic genomic activation could potentially harm the embryo. Our objective was to identify, appraise and summarize the available evidence comparing the effectiveness of blastocyst vs cleavage-stage embryo transfer.
METHODS
This was a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the transfer of blastocysts (days 5-6) with the transfer of cleavage-stage embryos (days 2-3) in women undergoing in-vitro fertilization or intracytoplasmic sperm injection. The last electronic searches were run on 1 August 2016. Abstracts and studies with a mean difference between the two study groups of > 0.5 for the number of embryos transferred were excluded.
RESULTS
We screened 1187 records and assessed 33 potentially eligible studies. Twelve studies were included, comprising a total of 1200 women undergoing blastocyst transfer and 1218 undergoing cleavage-stage embryo transfer. We observed low-quality evidence of no significant difference of blastocyst transfer on live birth/ongoing pregnancy (relative risk (RR), 1.11 (95% CI, 0.92-1.35), 10 RCTs, 1940 women, I = 54%), clinical pregnancy (RR, 1.10 (95% CI, 0.93-1.31), 12 RCTs, 2418 women, I = 64%), cumulative pregnancy (RR, 0.89 (95% CI, 0.67-1.16), four RCTs, 524 women, I = 63%) and miscarriage (RR, 1.08 (95% CI, 0.74-1.56), 10 RCTs, 763 pregnancies, I = 0%). There was moderate-quality evidence of a decrease in the number of women with surplus embryos after the blastocyst-stage embryo transfer (RR, 0.78 (95% CI, 0.66-0.91)). Overall, the quality of the evidence was limited by the quality of the included studies and by unexplained inconsistency across studies.
CONCLUSIONS
Current evidence shows no superiority of blastocyst compared with cleavage-stage embryo transfer in clinical practice. As the quality of the evidence for the primary outcomes is low, additional well-designed RCTs are still needed before robust conclusions can be drawn. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Topics: Blastocyst; Cleavage Stage, Ovum; Embryo Transfer; Female; Humans; Pregnancy; Pregnancy Outcome; Pregnancy Rate; Pregnancy, Multiple
PubMed: 27731533
DOI: 10.1002/uog.17327 -
Association between estrogen levels and temporomandibular disorders: a systematic literature review.Przeglad Menopauzalny = Menopause Review Dec 2015To evaluate whether the hypothesis that estrogen levels are associated with temporomandibular disorders (TMD) in humans can be confirmed or contradicted by available... (Review)
Review
INTRODUCTION
To evaluate whether the hypothesis that estrogen levels are associated with temporomandibular disorders (TMD) in humans can be confirmed or contradicted by available literature.
MATERIAL AND METHODS
A systematic review based on the content of PubMed, Scopus, and Cochrane Library databases was performed. Studies were identified using a combination of key words 'temporomandibular disorder' and 'estrogen'. Nine studies were included into our review.
RESULTS
The relationship between estrogen levels and TMD was found in seven out of nine reviewed papers. Results from two papers suggest that a high estrogen level is associated with an increased prevalence of TMD. Five additional papers found a relationship between a low estrogen level and an increase in TMD pain. In considering the value of evidence and inconsistencies of results in the reviewed publications, we state that there is weak evidence to support the hypothesis that estrogen levels are associated with TMD.
CONCLUSIONS
Results of reviewed studies were divergent and sometimes contradictory. One possible explanation is that estrogen influences TMD pain processing differently than temporomandibular joints (TMJ) structures, as shown in many animal studies. Estrogen may influence TMD pain processing differently than TMJ structures. We suggest consideration of the dual action of estrogen when planning future studies on its association with TMD.
PubMed: 26848299
DOI: 10.5114/pm.2015.56538 -
Ultrasound in Obstetrics & Gynecology :... Oct 2014To identify, appraise and summarize the available evidence regarding the effectiveness and safety of time-lapse embryo monitoring on the main outcomes of assisted... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To identify, appraise and summarize the available evidence regarding the effectiveness and safety of time-lapse embryo monitoring on the main outcomes of assisted reproductive techniques.
METHODS
In this systematic review and meta-analysis, we included only randomized controlled trials (RCTs) comparing time-lapse embryo imaging with standard embryo monitoring. Our primary outcomes were live births (efficacy) and congenital abnormalities (safety). The secondary outcomes were clinical pregnancy, ongoing pregnancy and miscarriage.
RESULTS
Two RCTs were considered eligible, and their data were extracted and included in a meta-analysis. In both studies embryos were transferred at the blastocyst stage. No studies reported rates of live birth or congenital abnormalities. Our estimates were not sufficiently precise to identify whether time-lapse monitoring provided a small benefit, no effect or minor harm on rates of clinical pregnancy (relative risk (RR), 1.05 (95% CI, 0.80-1.38)) or ongoing pregnancy (RR, 1.05 (95% CI, 0.76-1.45)), based on two studies involving 138 women with moderate-quality evidence. Considering the available data, we were unable to determine whether the intervention poses substantial benefit, no effect or substantial harm in the risk of miscarriage (RR, 0.95 (95% CI, 0.30-2.99)), based on two studies involving 76 clinical pregnancies with low-quality evidence.
CONCLUSIONS
Time-lapse embryo imaging is unlikely to have a large effect on the chance of achieving clinical and/or ongoing pregnancy when transferring embryos at the blastocyst stage. More studies are required to improve the quality of the current evidence and also to examine whether this intervention is useful when transferring embryos at the cleavage stage.
Topics: Adolescent; Adult; Cleavage Stage, Ovum; Embryo Transfer; Female; Humans; Pregnancy; Pregnancy Outcome; Pregnancy Rate; Reproductive Techniques, Assisted; Time-Lapse Imaging; Young Adult
PubMed: 24890582
DOI: 10.1002/uog.13428 -
The Cochrane Database of Systematic... Nov 2015Many media are commercially available for culturing pre-implantation human embryos in assisted reproductive technology (ART) cycles. It is unknown which culture medium... (Review)
Review
BACKGROUND
Many media are commercially available for culturing pre-implantation human embryos in assisted reproductive technology (ART) cycles. It is unknown which culture medium leads to the best success rates after ART.
OBJECTIVES
To evaluate the safety and effectiveness of different human pre-implantation embryo culture media in used for in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) cycles.
SEARCH METHODS
We searched the Cochrane Menstrual Disorders and Subfertility Group's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the National Research Register, the Medical Research Council's Clinical Trials Register and the NHS Center for Reviews and Dissemination databases from January 1985 to March 2015. We also examined the reference lists of all known primary studies, review articles, citation lists of relevant publications and abstracts of major scientific meetings.
SELECTION CRITERIA
We included all randomised controlled trials which randomised women, oocytes or embryos and compared any two commercially available culture media for human pre-implantation embryos in an IVF or ICSI programme.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected the studies, assessed their risk of bias and extracted data. We sought additional information from the authors if necessary. We assessed the quality of the evidence using Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methods. The primary review outcome was live birth or ongoing pregnancy.
MAIN RESULTS
We included 32 studies in this review. Seventeen studies randomised women (total 3666), three randomised cycles (total 1018) and twelve randomised oocytes (over 15,230). It was not possible to pool any of the data because each study compared different culture media.Only seven studies reported live birth or ongoing pregnancy. Four of these studies found no evidence of a difference between the media compared, for either day three or day five embryo transfer. The data from the fifth study did not appear reliable.Six studies reported clinical pregnancy rate. One of these found a difference between the media compared, suggesting that for cleavage-stage embryo transfer, Quinn's Advantage was associated with higher clinical pregnancy rates than G5 (odds ratio (OR) 1.56; 95% confidence interval (CI) 1.12 to 2.16; 692 women). This study was available only as an abstract and the quality of the evidence was low.With regards to adverse effects, three studies reported multiple pregnancies and six studies reported miscarriage. None of them found any evidence of a difference between the culture media used. None of the studies reported on the health of offspring.Most studies (22/32) failed to report their source of funding and none described their methodology in adequate detail. The overall quality of the evidence was rated as very low for nearly all comparisons, the main limitations being imprecision and poor reporting of study methods.
AUTHORS' CONCLUSIONS
An optimal embryo culture medium is important for embryonic development and subsequently the success of IVF or ICSI treatment. There has been much controversy about the most appropriate embryo culture medium. Numerous studies have been performed, but no two studies compared the same culture media and none of them found any evidence of a difference between the culture media used. We conclude that there is insufficient evidence to support or refute the use of any specific culture medium. Properly designed and executed randomised trials are necessary.
Topics: Abortion, Spontaneous; Culture Media; Embryo Transfer; Embryo, Mammalian; Female; Fertilization in Vitro; Humans; Live Birth; Oocytes; Pregnancy; Pregnancy Rate; Pregnancy, Multiple; Randomized Controlled Trials as Topic; Sperm Injections, Intracytoplasmic
PubMed: 26585317
DOI: 10.1002/14651858.CD007876.pub2 -
Medicine Dec 2017Pretreatment of myoinositol is a very new method that was evaluated in multiple small studies to manage poor ovarian response in assisted reproduction. This study was to... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Pretreatment of myoinositol is a very new method that was evaluated in multiple small studies to manage poor ovarian response in assisted reproduction. This study was to determine the efficacy of myoinositol supplement in infertile women undergoing ovulation induction for intracytoplasmic sperm injection (ICSI) or in vitro fertilization embryo transfer (IVF-ET).
METHODS
A meta-analysis and systematic review of published articles evaluating the efficacy of myo-inositol in patients undergoing ovulation induction for ICSI or IVF-ET was performed.
RESULTS
Seven trials with 935 women were included. Myoinositol supplement was associated with significantly improved clinical pregnancy rate [95% confidence interval (CI), 1.04-1.96; P = .03] and abortion rate (95% CI, 0.08-0.50; P = .0006). Meanwhile, Grade 1 embryos proportion (95% CI, 1.10-2.74; P = .02), germinal vescicle and degenerated oocytes retrieved (95% CI, 0.11-0.86; P = .02), and total amount of ovulation drugs (95% CI, -591.69 to -210.39; P = .001) were also improved in favor of myo-inositol. There were no significant difference in total oocytes retrieved, MII stage oocytes retrieved, stimulation days, and E2 peak level.
CONCLUSIONS
Myoinositol supplement increase clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET. It may improve the quality of embryos, and reduce the unsuitable oocytes and required amount of stimulation drugs.
Topics: Adult; Dietary Supplements; Embryo Transfer; Female; Fertilization in Vitro; Humans; Infertility, Female; Inositol; Oocytes; Ovulation Induction; Pregnancy; Pregnancy Rate; Sperm Injections, Intracytoplasmic
PubMed: 29245250
DOI: 10.1097/MD.0000000000008842