Ultrasound-guided embryo transfer improves pregnancy rates and increases the frequency of easy transfers

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.

Interventions to optimize embryo transfer in women undergoing assisted conception: a comprehensive systematic review and meta-analyses

BACKGROUND

Several interventions and techniques are suggested to improve the outcome of embryo transfer (ET) in assisted conception. However, there remains no consensus on the optimal practice, with high variations among fertility specialists.

OBJECTIVE AND RATIONALE

We conducted a comprehensive systematic review and meta-analyses of randomized controlled trials (RCTs) aiming to identify effective interventions that could be introduced around the time of ET to improve reproductive outcomes.

SEARCH METHODS

We searched the electronic databases (MEDLINE, EMBASE and Cochrane CENTRAL) from inception until March 2021 using a multi-stage search strategy of MeSH terms and keywords, and included all RCTs that evaluated an intervention in the 24-h period before/after ET in women undergoing IVF/ICSI. Our primary outcome was clinical pregnancy rate post-ET confirmed as viable pregnancy on ultrasound scan. We assessed the risk of bias in included trials and extracted data in duplicate. We pooled data using a random-effect meta-analysis and reported using risk ratio (RR) with 95% CI. We explored publication bias and effect modifiers using subgroup analyses.

OUTCOMES

Our search yielded 3685 citations of which we included 188 RCTs (38 interventions, 59 530 participants) with a median sample size of 200 (range 26-1761). The quality of included RCTs was moderate with most showing a low risk of bias for randomization (118/188, 62.8%) and attrition (105/188, 55.8%) but there was a significant risk of publication bias (Egger's test P = 0.001). Performing ET with ultrasound guidance versus clinical touch (n = 24, RR 1.265, 95% CI 1.151-1.391, I2 = 38.53%), hyaluronic acid versus routine care (n = 9, RR 1.457, 95% CI 1.197-1.261, I2 = 46.48%) and the use of a soft versus hard catheter (n = 27, RR 1.122, 95% CI 1.028-1.224, I2 = 57.66%) led to higher clinical pregnancy rates. Other pharmacological add-ons also showed a beneficial effect including granulocyte colony-stimulating factor (G-CSF: n = 4, RR 1.774, 95% CI 1.252-2.512, I2 = 0), Atosiban (n = 7, RR 1.493, 95% CI 1.184-1.882, I2 = 68.27%) and hCG (n = 17, RR 1.232, 95% CI 1.099-1.382, I2 = 57.76%). Bed rest following ET was associated with a reduction in clinical pregnancy (n = 6, RR 0.857, 95% CI 0.741-0.991, I2 = 0.01%). Other commonly used interventions, such as non-steroidal anti-inflammatory drugs, prophylactic antibiotics, acupuncture and cervical mucus removal, did not show a significant benefit on reproductive outcomes. Our effect estimates for other important outcomes, including miscarriage and live birth, were limited by the varied reporting across included RCTs.

WIDER IMPLICATIONS

Using ultrasound guidance, soft catheters and hyaluronic acid at the time of ET appears to increase clinical pregnancy rates. The use of Atosiban, G-CSF and hCG showed a trend towards increased clinical pregnancy rate, but larger trials are required before adopting these interventions in clinical practice. Bed rest post-ET was associated with a reduction in clinical pregnancy and should not be recommended.

National Survey Highlights the Urgent Need for Standardisation of Embryo Transfer Techniques in the UK

Embryo transfer (ET) is one of the vital steps in the in vitro fertilisation (IVF) process, yet there is wide variation in ET technique throughout the UK, without a nationally approved standardised approach. The aim of this study was to gain contemporaneous information regarding the current clinical ET practice in the UK.

METHOD

A 38-question electronic survey was distributed to the 79 UK Human Fertilisation and Embryology Authority (HFEA) registered clinics performing ETs.

RESULTS

In total, 59% (47/79) of units responded, 83% (39/47) performing ultrasound-guided transfers, with 42% (20/47) of units using a tenaculum; 22% (10/45) would proceed with transfer regardless of fluid in the endometrial cavity. In 91% (43/47) of units, embryos were deposited in the upper/middle portion of the uterine cavity, but interpretation of this area ranged from 0.5 to >2 cm from the fundus, with 68% (32/47) allowing patients to mobilise immediately after transfer. In 60% (27/45) of clinics, success rates were based on clinical pregnancy rates (CPR).

CONCLUSION

Within the UK there is a wide range of variability in ET techniques, with >70% of discordance in survey-responses between clinics. Whilst there are areas of good practice, some disadvantageous techniques continue to persist. This survey emphasises the importance of developing a standardised, evidence-based approach to improve ET success rates.

Antibacterial and Antifungal Activity of the Human Endometrial Fluid during the Natural Cycle

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.

Proteomics based drug repositioning applied to improve in vitro fertilization implantation: an artificial intelligence model

Embryo implantation is one of the most inefficient steps in assisted reproduction, so the identifying drugs with a potential clinical application to improve it has a strong interest. This work applies artificial intelligence and systems biology-based mathematical modeling strategies to unveil potential treatments by computationally analyzing and integrating available molecular and clinical data from patients. The mathematical models of embryo implantation computationally generated here simulate the molecular networks underneath this biological process. Once generated, these models were analyzed in order to identify potential repositioned drugs (drugs already used for other indications) able to improve embryo implantation by modulating the molecular pathways involved. Interestingly, the repositioning analysis has identified drugs considering two endpoints: (1) drugs able to modulate the activity of proteins whose role in embryo implantation is already bibliographically acknowledged, and (2) drugs that modulate key proteins in embryo implantation previously predicted through a mechanistic analysis of the mathematical models. This second approach increases the scope open for examination and potential novelty of the repositioning strategy. As a result, a list of 23 drug candidates to improve embryo implantation after IVF was identified by the mathematical models. This list includes many of the compounds already tested for this purpose, which reinforces the predictive capacity of our approach, together with novel repositioned candidates (e.g., Infliximab, Polaprezinc, and Amrinone). In conclusion, the present study exploits existing molecular and clinical information to offer new hypotheses regarding molecular mechanisms in embryo implantation and therapeutic candidates to improve it. This information will be very useful to guide future research.Abbreviations: IVF: in vitro fertilization; EI: Embryo implantation; TPMS: Therapeutic Performance Mapping System; MM: mathematical models; ANN: Artificial Neuronal Networks; TNFα: tumour necrosis factor factor-alpha; HSPs: heat shock proteins; VEGF: vascular endothelial growth factor; PPARA: peroxisome proliferator activated receptor-α PXR: pregnane X receptor; TTR: transthyretin; BED: Biological Effectors Database; MLP: multilayer perceptron.

Effect of embryo transfer depth on IVF/ICSI outcomes: A randomized clinical trial

Background

Although there has been remarkable advancement in the field of assisted reproductive technology, implantation failure remains a significant issue in most infertile couples receiving these treatments. Embryo transfer is important in assisted reproductive technology and directly affects the implantation rates and pregnancy outcomes.

Objective

To assess the effect of two different distance embryo transfer sites from fundal endometrial surface on the outcomes of in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles.

Materials and Methods

A total of 180 women who were candidate for IVF/ ICSI/ embryo transfer in Yazd Research and Clinical Center for Infertility were equally assigned to two groups based on the distance between the fundal endometrial surface and catheter tip to investigate implantation, chemical and clinical pregnancy (group A: 15 ± 5 mm and group B: 25 ± 5 mm, respectively).

Results

The subjects in the group B showed significantly higher implantation rate, chemical and clinical pregnancy rate compared to the group A (p = 0.03, 0.01, 0.04, respectively). The rate of ongoing pregnancy and miscarriage indicated no significant differences between groups (p = 0.21, 0.27, respectively).

Conclusion

In conclusion, our study showed that the depth of embryo replacement inside the uterine cavity at a distance of 25 ± 5 mm beneath fundal endometrial surface have better effects on the pregnancy outcomes of IVF/ICSI cycles and can be considered as an important factor to improve the success of IVF cycles.

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 in vitro 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 (α-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.

Clinical Trial Registration Number

Eudra CT 2007-000960-25.

Predictive factors influencing pregnancy rate in frozen embryo transfer

PURPOSE

To evaluate the outcomes of embryo transfer (ET) and to identify the parameters influencing pregnancy outcomes.

METHODS

This study included 938 ET cycles involving single frozen and thawed good-quality blastocyst (Gardner grade ≥3BB) between August 2017 and January 2018. The significance of several parameters including endometrial thickness, position of the transferred air bubble, self-evaluation score by physicians, and uterus direction at ET as predictors of clinical pregnancy was evaluated using univariate and multivariate analyses.

RESULTS

Among 938 ET cycles, 462 (49.3%) resulted in a clinical pregnancy. Endometrial thickness was positively associated with clinical pregnancy in a linear trend. Between the variable position of the transferred air bubble and clinical pregnancy rate showed a curvilinear relationship. Clinical pregnancy rate was higher in cases with good self-evaluation score, whereas there was no difference between groups with different uterus directions. Univariate analysis of predictive parameters identified endometrial thickness, self-evaluation score by physicians, and position of air bubbles as significant predictors of clinical pregnancy, of which endometrial thickness and position of air bubbles appeared to be independently related to clinical pregnancy.

CONCLUSION

Endometrial thickness and the position of transferred air bubbles influenced clinical pregnancy in ET cycles.

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.

The lipidome of endometrial fluid differs between implantative and non-implantative IVF cycles

OBJECTIVE

To characterize the most relevant changes in the lipidome of endometrial fluid aspirate (EFA) in non-implantative cycles.

DESIGN

Lipidomics in a prospective cohort study.

SETTINGS

Reproductive unit of a university hospital.

PATIENTS

Twenty-nine women undergoing an IVF cycle. Fifteen achieved pregnancy and 14 did not.

INTERVENTION

Endometrial fluid aspiration immediately before performing embryo transfer.

MAIN OUTCOME MEASURES

Clinical pregnancy rate and lipidomic profiles obtained on an ultra-high performance liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC-ToF-MS)-based analytical platform.

RESULTS

The comparative analysis of the lipidomic patterns of endometrial fluid in implantative and non-implantative IVF cycles revealed eight altered metabolites: seven glycerophospholipids and an omega-6 polyunsaturated fatty acid. Then, women with a non-implantative cycle were accurately classified with a support vector machine algorithm including these eight lipid metabolites. The diagnostic performances of the algorithm showed an area under the receiver operating characteristic curve, sensitivity, specificity, and accuracy of 0.893 ± 0.07, 85.7%, 80.0%, and 82.8%, respectively.

CONCLUSION

A predictive lipidomic signature linked to the implantative status of the endometrial fluid has been found.

Expression and localization of tubulin cofactors TBCD and TBCE in human gametes

The tubulin cofactors TBCD and TBCE play an essential role in regulation of the microtubule dynamics in a wide variety of somatic cells, but little information is known about the expression of these cofactors in human sperm and oocytes. In this study, we focused on the investigation of the presence of, and the differential distribution of, the tubulin cofactors TBCD and TBCE in human sperm and during human oocyte maturation. We performed expression assays for TBCD and TBCE by reverse transcription-polymerase chain reaction (RT-PCR), western blot and immunofluorescence and verified the presence of both cofactors in human gametes. TBCD and TBCE were located mainly in the middle region and in the tail of the sperm while in the oocyte the localization was cytosolic. The mRNA of both tubulin cofactors were present in the human oocytes but not in sperm cells. This finding gives a first insight into where TBCD and TBCE could carry out their function in the continuous changes that the cytoskeleton experiences during gametogenesis and also prior to fertilization.

Ultrasound versus 'clinical touch' for catheter guidance during embryo transfer in women

BACKGROUND

Many women undergoing an assisted reproductive technology (ART) cycle will not achieve a live birth. Failure at the embryo transfer stage may be due to lack of good-quality embryo/s, lack of uterine receptivity, or the transfer technique itself. Numerous methods, including the use of ultrasound guidance for proper catheter placement in the endometrial cavity, have been suggested as more effective techniques of embryo transfer. This review evaluates the efficacy of ultrasound-guided embryo transfer (UGET) compared with 'clinical touch' (CTET), which is the traditional method of embryo transfer and relies on the clinician's tactile senses to judge when the transfer catheter is in the correct position.

OBJECTIVES

To determine whether ultrasound guidance compared with clinical touch improves pregnancy outcomes in women undergoing embryo transfer during ART cycles.

SEARCH METHODS

For the 2016 update of this review, we ran updated searches in the Cochrane Gynaecology and Fertility Group trials register (May 2015), the Cochrane Central Register of Controlled Trials (the Cochrane Library, May 2015), MEDLINE (2009 to May 2015), and EMBASE (2009 to May 2015). We also handsearched relevant conference proceedings: American Society for Reproductive Medicine (ASRM), European Society for Human Reproduction and Embryology (ESHRE), and International Federation of Gynecology and Obstetrics (FIGO). There were no language restrictions.

SELECTION CRITERIA

We included only randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and quality of trials and extracted data from those selected. We calculated odds ratio (OR) and 95% confidence interval (CI) for dichotomous outcomes. No outcomes were reported using continuous data. We assessed the overall quality of the evidence for the main findings using the GRADE working group methods.

MAIN RESULTS

This systematic review now has 21 included studies (four of which we added in the 2016 update), two studies awaiting assessment, and 47 excluded studies. In total, data for meta-analyses were available in 21 trials (n = 6218 women), of which only four reported live births.UGET was associated with an increased chance of a live birth/ongoing pregnancy compared with CTET (OR 1.47, 95% CI 1.30 to 1.65; 13 trials; n = 5859 women; I(2) = 74%; low-quality evidence). Sensitivity analysis by including only trials with low risk of selection bias or by using a random-effects model did not alter the effect. We estimate that for women with a chance of a live birth/ongoing pregnancy of 23% using CTET, this would increase to between 28% and 33% using UGET. We considered the quality of the evidence using GRADE methodology to be low.UGET was associated with an increase in the chance of a clinical pregnancy (OR 1.31, 95% CI 1.17 to 1.45; 20 trials; n = 6711 women; I(2) = 42%; moderate-quality evidence). We identified no differences between groups for the incidence of adverse events including multiple pregnancy, ectopic pregnancy, or miscarriage. These events were relatively rare, and sample sizes limited the ability to detect such differences.

AUTHORS' CONCLUSIONS

The evidence suggests ultrasound guidance improves the chance of live birth/ongoing and clinical pregnancies compared with clinical touch, without increasing the chance of multiple pregnancy, ectopic pregnancy, or miscarriage. Methodological limitations included: only four studies reporting details of both computerised randomisation techniques and adequate allocation concealment, only four studies reported on the outcome of live birth, and none of the nine studies that reported on ongoing pregnancy reported on live birth, suggesting possible reporting bias. Adequate reporting of randomisation and allocation concealment will improve the quality of future studies. The primary outcome measure of future studies should be the reporting of live births per woman randomised.

Dynamics of expression and localization of the cannabinoid system in granulosa cells during oocyte nuclear maturation

OBJECTIVE

To describe the expression of cannabinoid receptors CB1 and CB2 and cannabinoid-degrading enzymes fatty acid amide hydrolase (FAAH) and monoglyceride lipase (MGLL) in human granulosa cells and to investigate their differential distribution with respect to CB1 at various stages during the nuclear maturation of the oocyte.

DESIGN

Analysis of granulosa cells from germinal vesicle (GV), metaphase I (MI), and MII oocytes by quantitative reverse transcriptase-polymerase chain reaction, Western blot, and indirect immunofluorescence assays.

SETTING

Academic research laboratory.

PATIENT(S)

Patients from the Human Reproduction Unit of Cruces University Hospital undergoing intracytoplasmic sperm injection.

INTERVENTION(S)

We analyzed the granulosa cells of 300 oocytes from 53 patients. The oocyte maturation stages were 75 at GV stage, 51 at MI, and 174 at MII.

MAIN OUTCOME MEASURE(S)

The mRNA and protein expression of CB1, CB2, FAAH, and MGLL and localization in granulosa cells at each oocyte maturation stage.

RESULT(S)

CB1, FAAH, and MGLL are present in human granulosa cells during oocyte maturation, but the presence of CB2 receptor is not entirely clear in those cells. CB1 and FAAH were detected in the periphery of the granulosa cells from the GV to the MII oocytes, and they colocalized in some portions of the cell membrane. On the other hand, MGLL immunostaining was more homogeneous across the cell and overlapped with CB1 only weakly.

CONCLUSION(S)

The presence of the cannabinoid system in granulosa cells suggests a possible role of this system in the nuclear maturation of the oocyte.

Ultrasound guidance during embryo transfer: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To summarize the current evidence on the effect of using ultrasound (US) guidance during embryo transfer (ET).

METHODS

In this systematic review, we included randomized controlled trials examining the effect of the use of US guidance during ET; data from studies using the same catheter type in study arms were not pooled with the results from studies that used different catheter types.

RESULTS

Twenty-one studies were included in the quantitative analysis: 18 compared 'US guidance' with 'clinical touch', of which one was subsequently excluded from the quantitative meta-analysis owing to a lack of available data, three studies compared transvaginal US guidance with transabdominal US guidance, and one study compared 'hysterosonometry before ET' with US guidance. Comparison of the use of US guidance with clinical touch, in studies that used the same catheter type in the study arms, indicated a benefit of using US guidance during ET on the rates of live birth (relative risk (RR), 1.48 (95% CI, 1.16-1.87)), based on two studies involving 888 women with moderate-quality evidence, and on the rates of clinical pregnancy (RR, 1.32 (95% CI, 1.18-1.46)), based on 13 studies involving 3641 women with high-quality evidence. However, when comparing the use of US guidance with clinical touch in studies that used different catheter types, the results suggest that using US guidance during ET has no effect on the rates of reproductive outcome: live birth (RR, 0.99 (95% CI, 0.83-1.19)), based on one study involving 1649 women with moderate-quality evidence; clinical pregnancy (RR, 1.04 (95% CI, 0.89-1.21)), based on five studies involving 2949 women with moderate-quality evidence. The estimates for the rate of miscarriage and for the other identified comparisons were imprecise.

CONCLUSIONS

The available evidence suggests that there is a benefit of using US guidance during ET. However, both US-guided transfer and clinical touch should be considered acceptable, as the benefit of US is not large and should be balanced against the increased cost and need to change the catheter type. More studies are required before conclusions can be drawn regarding the effect of other techniques on reproductive outcome.

Assisted reproductive techniques

Assisted reproductive technologies (ART) encompass fertility treatments, which involve manipulations of both oocyte and sperm in vitro. This chapter provides a brief overview of ART, including indications for treatment, ovarian reserve testing, selection of controlled ovarian hyperstimulation (COH) protocols, laboratory techniques of ART including in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI), embryo transfer techniques, and luteal phase support. This chapter also discusses potential complications of ART, namely ovarian hyperstimulation syndrome (OHSS) and multiple gestations, and the perinatal outcomes of ART.

The Impact of the Depth of Embryo Replacement into the Uterine Cavity under Transabdominal Ultrasound Guidance on In Vitro Fertilization and Embryo Transfer Outcome

Aim: The aim of the present study was to determine the importance of the depth of embryo replacement into the uterine cavity (upper or lower half endometrial cavity) on the implantation clinical pregnancy rates.Material and Methods: In this prospective observational were included 160 patients underwent controlled ovarian hyperstimulation followed by IVF/ICSI and embryo transfer. On the day of embryo transfer under direct transabdominal ultrasound guidance, the transfer catheter was advanced to a defined distance from the uterine fundus, up to the point estimated for transfer: 10 ± 2.5 mm (Group A) and 15 ± 2.5 mm (Group B).Results: In total, 160 patients, aged 24-42 years were included in the study. Overall clinical pregnancy rate were 41.2%. Analysis of our results demonstrated that pregnancy rate is significantly influenced by transfer distance from the fundus where the  pregnancy rate decreases from 48.7% in group B to 34.5%  in group A (p<0.05). There was not significantly difference in abortion rate between the two groups.Conclusion: In conclusion, our results suggest that depth of embryo replacement inside the uterine cavity may influence the pregnancy rates and should be considered as an important factor to improve the success of IVF cycles.

Human chorionic gonadotropin (hCG) plasma levels at oocyte retrieval and IVF outcomes

PURPOSE

The aim of our study was to ascertain the influence of hCG levels at oocyte pick-up on IVF outcomes, and their relationship with clinical parameters.

METHODS

A prospective study was performed including 473 women undergoing IVF, aged under 40 years. Blood samples to analyze hCG levels were obtained at the time of follicular aspiration, 36 h after the administration of 250 μg of recombinant hCG.

RESULTS

Neither the numbers of oocytes obtained or fertilized, nor the pregnancy rate, were correlated with hCG levels. Moreover, hCG values were very similar in women who did and did not become pregnant (123.3 ± 48.7 and 117.5 ± 44.7 mUI/mL). Cases in which no oocytes were recovered after follicular aspiration had similar hCG levels to those in which more than 1 oocyte was obtained. On the other hand, hCG levels were negatively related to body mass index, weight, and age.

CONCLUSIONS

These data indicate that after the administration of 250 μg of recombinant hCG, hCG levels are not responsible for failure to recover oocytes. Specifically, there was no correlation between plasma hCG levels and the number of oocytes obtained or other markers of IVF outcome. There was, however, an inverse relationship with BMI, body weight and age.

Mid-follicular LH supplementation in women aged 35-39 years undergoing ICSI cycles: a randomized controlled study

This single-centre, randomized, parallel group, comparative study aimed to identify potential benefits of mid-follicular recombinant human LH (r-HLH) supplementation in women aged 35-39 years undergoing ovarian stimulation for intracytoplasmic sperm injection (ICSI). The main endpoint was the number of metaphase II oocytes retrieved. After pituitary suppression with a gonadotrophin-releasing hormone agonist, ovarian stimulation was initiated with recombinant human FSH (r-HFSH; 300-450 IU/day). On stimulation day 6, patients were randomized to receive r-HFSH alone or r-HFSH + r-HLH (r-HLH 150 IU/day) for the remainder of the stimulation period. Final follicular maturation was triggered with 250 μg of recombinant human chorionic gonadotrophin. After assessing oocyte nuclear maturity, oocyte were fertilized by ICSI and afterwards embryo quality was analyzed. Of the 131 women enrolled, 68 were allocated to r-HFSH alone and 63 to r-HFSH + r-HLH. No significant differences were observed in markers of either oocyte or embryo quality or quantity. However, higher rates of implantation and live birth per started cycle were observed with r-HLH supplementation than with r-HFSH alone. Although additional large studies are required to further investigate these findings, r-HLH supplementation for women aged 35-39 years undergoing ICSI is recommended as it may have a beneficial action on implantation.

Expression and localization of cannabinoid receptors in human immature oocytes and unfertilized metaphase-II oocytes

Endocannabinoid anandamide and cannabinoid receptors have been described in some organs of the female reproductive system, but little is known about the expression of these receptors in human oocytes. The aim of the study was to describe the expression of cannabinoid receptors in human oocytes and to investigate their differential distribution at various stages of meiotic resumption in human oocytes. A total of 750 human oocytes from 214 patients were analysed by Western blot, immunocytochemistry and PCR. For this study, oocytes that were not suitable for intracytoplasmic sperm injection (ICSI) (germinal-vesicle and metaphase-I stages), as well as metaphase-II oocytes that had not developed into an embryo after ICSI were used. Western blot analysis revealed the presence of CB1 and CB2 receptor proteins in human oocytes. CB1 and CB2 receptor immunostaining patterns changed during the various stages of meiotic resumption. Localization of CB1 receptor was peripheral at germinal-vesicle stage, homogeneous over the entire oocyte at metaphase I and peripheral at mature metaphase II. CB2 receptor localization was peripheral at germinal-vesicle and metaphase-I stages but homogeneous over the entire cell at metaphase II. This finding suggests a possible role for endocannabinoids, acting via receptors, in the maturation of female gametes and fertilization. The number of couples with sterility problems attending fertility programmes is rising but treatment is not always successful. Important problems associated with failure to conceive remain unresolved because many physiological aspects of human reproduction are still unknown. Endocannabinoids are endogenous chemical compounds that mimic the action of the main psychoactive component of marijuana, delta-9-tetrahydrocannabinol. An endogenous cannabinoid named anandamide has been found in human follicular fluid. Thus, in order to develop knowledge in this field, in the present study we have described the presence of the cannabinoid receptors CB1 and CB2 (the proteins required to mediate the action of the cannabinoids) in the early stages of meiotic resumption of oocytes (the stages before ovulation) and we could postulate that the endocannabinoids could act in the regulation of maturation of oocytes. Our study, together with other studies, indicates that the endocannabinoid system may play a role in human reproduction.

Mid-follicular LH supplementation in women aged 35-39 years undergoing ICSI cycles: a randomized controlled study

This single-centre, randomized, parallel group, comparative study aimed to identify potential benefits of mid-follicular recombinant human LH (r-HLH) supplementation in women aged 35-39 years undergoing ovarian stimulation for intracytoplasmic sperm injection (ICSI). The main endpoint was the number of metaphase II oocytes retrieved. After pituitary suppression with a gonadotrophin-releasing hormone agonist, ovarian stimulation was initiated with recombinant human FSH (r-HFSH; 300-450 IU/day). On stimulation day 6, patients were randomized to receive r-HFSH alone or r-HFSH + r-HLH (r-HLH 150 IU/day) for the remainder of the stimulation period. Final follicular maturation was triggered with 250 mug of recombinant human chorionic gonadotrophin. After assessing oocyte nuclear maturity, oocyte were fertilized by ICSI and afterwards embryo quality was analyzed. Of the 131 women enrolled, 68 were allocated to r-HFSH alone and 63 to r-HFSH + r-HLH. No significant differences were observed in markers of either oocyte or embryo quality or quantity. However, higher rates of implantation and live birth per started cycle were observed with r-HLH supplementation than with r-HFSH alone. Although additional large studies are required to further investigate these findings, r-HLH supplementation for women aged 35-39 years undergoing ICSI is recommended as it may have a beneficial action on implantation.

Factors affecting pregnancy in IVF: age and duration of embryo transfer

The aim of this retrospective study was to investigate factors affecting clinical pregnancy rates, especially age and duration of embryo transfer, in IVF/intracytoplasmic sperm injection cycles (1313 embryo transfers). Overall clinical pregnancy rate was 30.0% (n=394). Clinical pregnancy rates were found to be 31.6% for the <44 s interval, 25.9% for the 45-59 s interval and 23.6% for the > or = 60 s interval (P=0.020). In the <35 year age group, clinical pregnancy rates were 35.1%, 29.9% and 30.6%, and in the > or = 35 year age group, they were 26.9%, 21.0% and 13.4% (P=0.013), respectively. According to logistic regression analyses, the odds of failed pregnancy increased by 1.61 times [95% confidence interval (CI) 1.07-2.41] for embryo transfer durations longer than 60 s and odds ratios of a failed pregnancy were 1.53 (95% CI 1.18-1.99) in the > or = 35 year age group, 1.49 (95% CI 1.05-2.12) for fewer than five oocytes and 3.38 (95% CI 2.10-5.43) for fewer than two transferred embryos. In conclusion, to increase the likelihood of a successful pregnancy in women over 35 years of age, the duration of embryo transfer must be kept below 60 s. The number of oocytes obtained and the number of transferred embryos also play a role in the success of pregnancy.

Ultrasound versus 'clinical touch' for catheter guidance during embryo transfer in women

BACKGROUND

Many women undergoing an Assisted Reproductive Technology (ART) cycle will not achieve a live birth. Failure at the embryo transfer stage may be due to lack of good quality embryo/s, lack of uterine receptivity, or the transfer technique itself. Numerous methods, including the use of ultrasound guidance for proper catheter placement in the endometrial cavity, have been suggested as a more effective technique of embryo transfer. This review evaluates the effectiveness of ultrasound guided embryo transfer (UGET) compared with 'clinical touch' (CTET) the traditional method of embryo transfer.

OBJECTIVES

To determine whether ultrasound guidance influences treatment outcomes in women undergoing embryo transfer (ET) during assisted reproductive technology (ART) cycles.

SEARCH STRATEGY

Electronic databases were searched in November 2009. We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched November 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2009), MEDLINE (1970-2009), EMBASE (1985-2009), BIO Extracts (1980-2009). Relevant conference proceedings were also hand searched (ASRM, ESHRE and FIGO).

SELECTION CRITERIA

Only randomised controlled trials were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility and quality of trials and extracted data from those selected.

MAIN RESULTS

This update identified 59 potential trials of which 42 were excluded. Data for analysis was available in seventeen studies. One study reported live births and personal communication resulted in data relating to this outcome being obtained in two additional studies. There is no evidence of a significant difference in the outcome of live birth (OR 1.14 (95%CI0.93 to 1.39; P=0.02) although heterogeneity was high (64%) and the results should be interpreted with caution. Seven studies reported on ongoing pregnancies. The ongoing pregnancies per woman randomised associated with UGET (441/1254) was significantly higher than for clinical touch (350/1218) OR 1.38, 95%CI 1.16 to 1.64, P<0.0003). No statistically significant differences in the incidence of adverse events were identified between the comparison groups. These events are relatively rare and sample sizes limit the ability to detect such differences.

AUTHORS' CONCLUSIONS

The studies are limited by their quality with only two studies reporting details of both computerised randomisation techniques and adequate allocation concealment. Ultrasound guidance does appear to improve the chances of live/ongoing and clinical pregnancies compared with clinical touch methods. The quality of future studies should be improved with adequate reporting of randomisation, allocation concealment, and power calculations. The primary outcome measure of future studies should be the reporting of live births per woman randomised.

Does the timing of mock embryo transfer affect in vitro fertilization implantation and pregnancy rates?∗

The timing of a mock embryo transfer does not affect in vitro fertilization implantation or pregnancy rates. Performing a mock embryo transfer at the time of oocyte retrieval, 3 to 5 days before embryo transfer, does not have a deleterious effect on the endometrium.

The position of transferred air bubbles after embryo transfer is related to pregnancy rate

OBJECTIVE

The possibility to visualize the transfer air bubbles is one of the main benefits of ultrasonographic-guided embryo transfer. The objective of this study was to analyze the relation between the position of the air bubbles and pregnancy rates.

DESIGN

Prospective data-analysis.

SETTING

University fertility clinic.

PATIENT(S)

IVF and intracytoplasmic sperm injection patients.

INTERVENTION(S)

Transabdominal ultrasonographic guidance at embryo transfer.

MAIN OUTCOME MEASURE(S)

Pregnancy rate, length endometrial plate, distance catheter to fundus, distance air bubbles to fundus.

RESULT(S)

Analysis of 367 consecutive ultrasonographic-guided embryo transfers following IVF or intracytoplasmic sperm injection treatment. Both absolute and relative position of the air bubbles were significantly closer to the fundus in patients who became pregnant compared with patients who did not become pregnant. When the relative position of the air bubbles was in the fundal half of the endometrial plate pregnancy rates were significantly higher compared with the lower half of the endometrial plate, 43.0% and 24.4%, respectively, P=.002. Multiple regression analysis revealed the relative position as an independently associated determinant for pregnancy.

CONCLUSION(S)

The position of the air bubbles after embryo transfer is related to pregnancy rate; the highest pregnancy rates are found when the air bubbles end up closer to the fundus.

Uterine Position Change Between Mock and Real Embryo Transfers

OBJECTIVE

This study was designed to assess the change in uterine position between mock and real embryo transfers.

MATERIALS AND METHODS

A total of 386 embryo transfer cycles were reviewed, and the uterine position was recorded at the time of mock embryo transfer and then again at the time of real embryo transfer.

RESULTS

Of 254 patients with an anteverted uterus at mock transfer, only 3 (1.2%) were found to have a retroverted uterus at actual embryo transfer. Of 132 patients with a retroverted uterus at mock transfer, 24 (18%) had an anteverted uterus at actual embryo transfer (p < 0.0001).

CONCLUSION

Routine ultrasound-guided embryo transfer is suggested when a retroverted uterus is found at mock embryo transfer, as there is a significant chance that the uterine position will change.

The influence of abdominal ultrasound-guided embryo transfer on pregnancy rate: a preliminary report

To determine whether the use of abdominal ultrasound-guided embryo transfer improves the clinical pregnancy rate in patients undergoing in vitro fertilization, 50 fresh cycles with day 3 embryo transfer were studied; 27 patients were randomized to ultrasound-guided transfers, and 23 patients were randomized to clinical touch transfers. Although the clinical pregnancy rate was not statistically different (18.5% in the ultrasound-guided group vs. 17.4% in the clinical touch group), the use of abdominal ultrasound during the embryo transfer procedure provided a greater degree of confidence and satisfaction to both patients and physicians.

The impact of the depth of embryo replacement on IVF outcome

PURPOSE

To evaluate the effect of the depth of embryo transfer replacement on clinical pregnancy rate.

METHODS

Data from a total of 104 consecutive embryo transfers performed on 104 women aged 26-37 years were prospectively collected for this study. All patients underwent a standard down regulation protocol for ovarian stimulation. Oocytes retrieval were performed at 36 h after hCG administration. Embryo transfer took place at 48 h after insemination. The patients were matched in two groups according to the distance between the tip of the catheter and the uterine fundus at transfer (group A > 10 < 15 mm and group B < or = 10 mm). The same method of loading embryos into the embryo transfer catheter was used.

RESULTS

Clinical pregnancy rates varied significantly (p < or = 0.05) between the two groups: 27.7% in group A and 14% in group B. The number and quality of embryos transferred did not differ between the groups.

CONCLUSIONS

The results suggest that the depth of embryo replacement may be an important variable in embryo transfer technique.

Ultrasound-guided embryo transfer does not offer any benefit in clinical outcome: a randomized controlled trial

BACKGROUND

Ultrasound-guided embryo transfer (ET) is widely suggested as a standard clinical practice that improves overall embryo implantation and pregnancy rates. Various studies of this issue suffer from methodological pitfalls, so that a randomized controlled trial, which overcomes these problems, might be valuable.

METHODS

Three hundred women aged <40, who underwent fresh ET, were included in this randomized, double-blind controlled trial. The K-J-SPPE echo tip soft catheter was used for the ultrasound-guided ET and the traditional K-Soft catheter for ETs not using ultrasound. One experienced operator performed all ETs. The primary study outcome was overall pregnancy rate (defined as the number of positive hCG results per transfer).

RESULTS

No significant differences between groups were found regarding baseline patient and embryological characteristics, except for male factor and unexplained infertility (higher in the blind and ultrasound-guided ET group, respectively, P < 0.05). Overall pregnancy rates were 53.3 and 51.3% in the ultrasound-guided and blind ET group, respectively. Two ectopic pregnancies were reported in each group. Difficulty in cervical negotiation did not differ between the two groups.

CONCLUSIONS

In patients undergoing ET by an experienced operator, ultrasound guidance did not provide any benefit in terms of overall clinical pregnancy and embryo implantation rates.

Ultrasound versus 'clinical touch' for catheter guidance during embryo transfer in women

BACKGROUND

Many women undergoing an Assisted Reproductive Technology (ART) cycle will not achieve a live birth. Failure at the embryo transfer stage may be due to poor embryo quality, lack of uterine receptivity, or the transfer technique itself. Numerous methods, including the use of ultrasound guidance for proper catheter placement in the endometrial cavity, have been suggested as a means of improving the technique of embryo transfer. This review evaluates the effectiveness of ultrasound (UGET) in comparison with 'clinical touch' embryo transfer (CTET) the traditional method of embryo transfer.

OBJECTIVES

:To determine whether ultrasound guidance influences treatment outcomes in women undergoing embryo transfer (ET) during assisted reproductive technology (ART) cycles.

SEARCH STRATEGY

All electronic databases were searched on 20 th August 2006. We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched August 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2006), MEDLINE (1970-2006), EMBASE (1985-2006), BIO Extracts (1980-2006). Relevant conference proceedings were also hand searched (ASRM, ESHRE and FIGO).

SELECTION CRITERIA

Only randomised controlled trials were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility and quality of trials and extracted data from those selected.

MAIN RESULTS

Thirteen out of fifteen identified studies were eligible for analysis. No study reported live births, however, personal communication resulted in data relating to this outcome being obtained in two of the studies. Six studies reported on ongoing pregnancies. The live birth/ ongoing pregnancies per woman randomised associated with UGET (452/1376) was significantly higher than for clinical touch (353/1338) OR 1.40, 95%CI 1.18 to 1.66, P<0.0001). This means, for example, that for a population of women with a 25% chance of pregnancy using clinical touch this would be increased to 32% (28% to 46%) by using UGET. There were no statistically significant differences in the incidence of adverse events between the two comparison groups with the exception of blood on the catheter.

AUTHORS' CONCLUSIONS

The studies are limited by their quality with only one of the thirteen studies reporting details of both computerised randomisation techniques and adequate allocation concealment. Ultrasound guidance does appear to improve the chances of live/ongoing and clinical pregnancies compared with clinical touch methods. The quality of future studies should be improved with adequate reporting of randomisation, allocation concealment, and power calculations. The primary outcome measure of future studies should be the reporting of live births per woman randomised.

Use of phenazopyridine for reducing discomfort during embryo transfer

OBJECTIVE

The embryo transfer is a critical part of in vitro fertilization. When performed under abdominal ultrasound guidance, the embryo transfer procedure requires a full bladder. Patients often state that the discomfort of the distended bladder causes more pain than the actual transfer procedure. Phenazopyridine HCl is a bladder analgesic. The objective of this study was to determine if a single dose of phenazopyridine prior to embryo transfer reduces patient discomfort during that procedure.

DESIGN

Prospective randomized double-blinded clinical trial.

SETTING

University-based Reproductive Medicine practice.

PATIENT(S)

Eighty-five reproductive age infertile women undergoing in vitro fertilization.

INTERVENTION(S)

Phenazopyridine (200 mg) or placebo taken 1 hour prior to embryo transfer utilizing transabdominal sonography.

MAIN OUTCOME MEASURE(S)

Pain as assessed by visual analogue pain scale and physician and nurse assessment of patient discomfort.

RESULT(S)

Study groups were similar in their demographic background. Mean pain score as assessed by a visual analogue pain scale during the procedure was 2.95 +/- 2.4 in the placebo group, and 3.03 +/- 2.6 in the active medication group (NS). There were also no significant differences in the observations of pain assessments.

CONCLUSION(S)

Phenazopyridine used in a single dose prior to embryo transfer does not alleviate patient discomfort.