Recurrent implantation failure in assisted reproduction: how to counsel and manage. B. Treatment options that have not been proven to benefit the couple

Recurrent Implantation Failure: Bioinformatic Discovery of Biomarkers and Identification of Metabolic Subtypes

Recurrent implantation failure (RIF) is a challenging scenario from different standpoints. This study aimed to investigate its correlation with the endometrial metabolic characteristics. Transcriptomics data of 70 RIF and 99 normal endometrium tissues were retrieved from the Gene Expression Omnibus database. Common differentially expressed metabolism-related genes were extracted and various enrichment analyses were applied. Then, RIF was classified using a consensus clustering approach. Three machine learning methods were employed for screening key genes, and they were validated through the RT-qPCR experiment in the endometrium of 10 RIF and 10 healthy individuals. Receiver operator characteristic (ROC) curves were generated and validated by 20 RIF and 20 healthy individuals from Peking University People's Hospital. We uncovered 109 RIF-related metabolic genes and proposed a novel two-subtype RIF classification according to their metabolic features. Eight characteristic genes (SRD5A1, POLR3E, PPA2, PAPSS1, PRUNE, CA12, PDE6D, and RBKS) were identified, and the area under curve (AUC) was 0.902 and the external validated AUC was 0.867. Higher immune cell infiltration levels were found in RIF patients and a metabolism-related regulatory network was constructed. Our work has explored the metabolic and immune characteristics of RIF, which paves a new road to future investigation of the related pathogenic mechanisms.

Allogeneic lymphocytes immunotherapy in female infertility: Lessons learned and the road ahead

The endometrium is an essential tissue in the normal immunologic dialogue between the mother and the conceptus, which is necessary for the proper establishment and maintenance of a successful pregnancy. It's become evident that the maternal immune system plays a key role in the normal pregnancy's initiation, maintenance, and termination. In this perspective, the immune system contributes to regulating all stages of pregnancy, thus immunological dysregulation is thought to be one of the major etiologies of implantation failures. Many researchers believe that immune therapies are useful tactics for improving the live births rate in certain situations. Lymphocyte immunotherapy (LIT) is an active form of immunotherapy that, when used on the relevant subgroups of patients, has been shown in multiple trials to dramatically enhance maternal immunological balance and pregnancy outcome. The primary goal of LIT is to regulate the immune system in order to create a favorable tolerogenic immune milieu and tolerance for embryo implantation. However, there are a plethora of influential factors influencing its therapeutic benefits that merit to be addressed. The objective of our study is to discuss the mechanisms and challenges of allogeneic LIT.

Cellular and Molecular Nature of Fragmentation of Human Embryos

Embryo fragmentation represents a phenomenon generally characterized by the presence of membrane-bound extracellular cytoplasm into the perivitelline space. Recent evidence supports the cellular and molecular heterogeneity of embryo fragments. In this narrative review, we described the different embryo fragment-like cellular structures in their morphology, molecular content, and supposed function and have reported the proposed theories on their origin over the years. We identified articles related to characterization of embryo fragmentation with a specific literature search string. The occurrence of embryo fragmentation has been related to various mechanisms, of which the most studied are apoptotic cell death, membrane compartmentalization of altered DNA, cytoskeletal disorders, and vesicle formation. These phenomena are thought to result in the extrusion of entire blastomeres, release of apoptotic bodies and other vesicles, and micronuclei formation. Different patterns of fragmentation may have different etiologies and effects on embryo competence. Removal of fragments from the embryo before embryo transfer with the aim to improve implantation potential should be reconsidered on the basis of the present observations

Efficacy of therapies and interventions for repeated embryo implantation failure: a systematic review and meta-analysis

The aim of the present systematic review and meta-analysis was to assess the effect of the different therapeutic options for repeated embryo implantation failure (RIF) on a subsequent IVF cycle outcome. Twenty-two RCTs and nineteen observational studies were included. Pooling of results showed a beneficial effect of intrauterine PBMC infusion on both CPR (RR 2.18; 95% CI 1.58-3.00; p < 0.00001; OR 2.03; 95% CI 1.22-3.36; p = 0.006) and LBR (RR 2.41; 95% CI 1.40-4.16; p = 0.002; OR 3.73; 95% CI 1.13-12.29; p = 0.03), of subcutaneous G-CSF administration on CPR (RR 2.29; 95% CI 1.58-3.31; p < 0.0001) and of intrauterine PRP infusion on CPR (RR 2.45; 95% CI 1.55-3.86; p = 0.0001). Observational studies also demonstrated a positive effect of IVIG and intrauterine hCG infusion on both CPR and LBR and of atosiban on CPR. Studies investigating intrauterine G-CSF infusion, LMWH, intravenous intralipid, hysteroscopy, blastocyst-stage ET, ZIFT, PGT-A and AH failed to observe an impact on IVF outcome. The quality of the evidence that emerged from RCTs focused on intrauterine PBMC infusion and subcutaneous G-CSF administration was moderate. For all other therapies/interventions it varied from low to very low. In conclusion, intrauterine PBMC infusion and subcutaneous G-CSF administration are the most promising therapeutic options for RIF. However, further well conducted RCTs are necessary before their introduction into clinical practice.

The sequential embryo transfer compared to blastocyst embryo transfer in in vitro fertilization (IVF) cycle in patients with the three repeated consecutive IVF. A randomized controlled trial

The purpose of this study was to determine the pregnancy rate in the double sequential transfer of embryos on both day 3 and day 5 compared to day 5 alone, in in vitro fertilization-embryo transfer (IVF/ET) in patients with the three repeated consecutive IVF failures. In this controlled trial, women scheduled for IVF/ET with the three repeated consecutive IVF failures were randomized to either sequential transfer of embryos on day 2 and on day 5 after ovum pick-up (group 1, n = 60) or blastocyst ET on day 5 (group 2, n = 60) as a control group. The primary outcome measures were the chemical and clinical pregnancy rate. Baseline and cycle characteristics were comparable in both groups. Chemical and clinical pregnancy rate was similar in the sequential ET group (40%) compared to the day 5 of ET group (38.3%) (p value = .85). It seems that the double ET does not increase the chance of pregnancy rate compared to blastocyst ET on day 5 in the patients with the three repeated IVF-ET failures.

Intrauterine administration of peripheral mononuclear cells in recurrent implantation failure: a systematic review and meta-analysis

It has been proposed that intrauterine administration of peripheral blood mononuclear cells (PBMCs) modulates maternal immune response through a cascade of cytokines, chemokines and growth factors to favor implantation. We conducted a meta-analysis to verify the effect of intrauterine PBMC administration on the outcome of embryo transfer in women with recurrent implantation failure (RIF). All relevant trials published in PubMed, Web of Science and Cochrane library databases were searched. Two randomized controlled trials and three cohort studies (1173 patients in total) matched the inclusion criteria. No differences in live birth rates were seen between the PBMC-treated patients and controls (OR: 1.65, 95% CI: 0.84–3.25; p = 0.14; I²: 66.3%). The clinical pregnancy rate was significantly higher in women who received intrauterine PBMCs before embryo transfer compared with those who did not (OR: 1.65, 95% CI: 1.30–2.10; p = 0.001, heterogeneity; I²: 60.6%). Subgroup analyses revealed a significant increase in clinical pregnancy rates with the administration of PBMCs in women with ≥3 previous failures compared with controls (OR: 2.69, 95% CI: 1.53–4.72; p = 0.001, I²: 38.3%). In summary, the data did not demonstrate an association between the administration of PBMCs into the uterine cavity before fresh or frozen-thawed embryo transfer and live birth rates in women with RIF. Whether intrauterine PBMC administration significantly changes live birth and miscarriage rates requires further investigation.

The HLA-G 14-bp polymorphism and recurrent implantation failure: a meta-analysis

PURPOSE

The human leucocyte antigen-G (HLA-G) 14-bp insertion/deletion polymorphism was implicated in recurrent implantation failure (RIF), but individual published studies showed inconclusive results. Thus, a meta-analysis was performed to clarify the effect of HLA-G 14-bp polymorphism on RIF risk.

METHODS

A comprehensive search for relevant articles was conducted. The odds ratios (ORs) and 95% confidence intervals (CIs) for HLA-G 14-bp polymorphism and RIF were calculated.

RESULTS

A total of five studies were included. In studies conducted in RIF patients and controls who had at least one spontaneous pregnancy, meta-analysis revealed no statistically significant association between the HLA-G 14-bp polymorphism and RIF in allele contrast and all genetic models in the overall population, but significant association was found in the population of Caucasian origin under allele contrast (OR = 1.73, 95% CI, 1.20, 2.50) and genetic models of +14 bp/+14 bp vs. -14 bp/-14 bp (OR = 3.09, 95% CI, 1.43, 6.65). In studies conducted in RIF patients and controls who had successful pregnancy following IVF-ET, the meta-analysis showed that there was statistically significant association between the HLA-G 14 bp polymorphism and RIF in allele contrast (OR = 1.74, 95% CI, 1.13, 2.67) and genetic models of +14 bp/+14 bp vs. -14 bp/-14 bp (OR = 10.20, 95% CI, 2.47, 42.14) and dominant model (OR = 4.34, 95% CI, 1.72, 10.92). No publication bias was found in the present studies.

CONCLUSIONS

This meta-analysis suggested that the HLA-G 14-bp insertion allele may increase the risk of RIF in Caucasians. Further studies with large sample size of different ethnic populations are necessary.

Thrombophilia and assisted reproduction technology-any detrimental impact or unnecessary overuse?

PURPOSE

The aim of this study is to provide an overview of the studies investigating a possible association between thrombophilia and assisted reproductive technology (ART) outcome.

METHODS

This is a literature review.

RESULTS

Congenital thrombophilias (CoT) are reported to be associated with pregnancy loss. However, the association between CoT and early pregnancy loss is weak and does not necessarily support causation. CoT are more likely to be associated with late fetal loss. Even though data pooled from case-control and cohort studies suggest an increased risk of ART failure in women with CoTs, there seems no association when the analysis is confined to better quality cohort studies. The evidence supporting anticoagulation to improve ART outcome in CoT carriers is weak. Likewise, studies on antiphospholipid antibodies (APAs) and ART outcome suffer from multiple methodological limitations and a detrimental impact of APA positivity is controversial. Empirical administration of heparin or low molecular weight heparin to women with recurrent ART failures is supported by weak evidence. Importantly, thrombophilias are likely to increase thrombotic complications after ovarian stimulation for ART.

CONCLUSIONS

Current evidence does not support routinely testing for or treatment of thrombophilia in the setting of ART nor in couples with implantation failure. A careful personal and family history should be obtained and a risk assessment for thrombotic complications should be made in every woman undergoing ovarian stimulation. If positive, testing for thrombophilia is warranted.

An endometrial gene expression signature accurately predicts recurrent implantation failure after IVF

The primary limiting factor for effective IVF treatment is successful embryo implantation. Recurrent implantation failure (RIF) is a condition whereby couples fail to achieve pregnancy despite consecutive embryo transfers. Here we describe the collection of gene expression profiles from mid-luteal phase endometrial biopsies (n = 115) from women experiencing RIF and healthy controls. Using a signature discovery set (n = 81) we identify a signature containing 303 genes predictive of RIF. Independent validation in 34 samples shows that the gene signature predicts RIF with 100% positive predictive value (PPV). The strength of the RIF associated expression signature also stratifies RIF patients into distinct groups with different subsequent implantation success rates. Exploration of the expression changes suggests that RIF is primarily associated with reduced cellular proliferation. The gene signature will be of value in counselling and guiding further treatment of women who fail to conceive upon IVF and suggests new avenues for developing intervention.

Higher pregnancy rates using testicular sperm in men with severe oligospermia

OBJECTIVE

To evaluate assisted reproductive technology (ART) outcomes using testicular sperm in oligospermic men who previously failed to achieve paternity using TUNEL-positive ejaculated sperm.

DESIGN

Retrospective cohort.

SETTING

Academic medical center.

PATIENT(S)

Twenty-four oligospermic men who failed one or more ART cycles using ejaculated sperm with TUNEL-positive proportion >7%, and subsequently underwent microsurgical testicular sperm extraction (TESE).

INTERVENTION(S)

TESE followed by intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

TUNEL-positive level in ejaculated and testicular sperm; clinical pregnancy.

RESULT(S)

The mean TUNEL-positive level was 24.5% for ejaculated sperm, and 4.6% for testicular sperm. Clinical pregnancy was achieved in the first ART cycle with testicular sperm in 12 (50%) out of 24 couples. There was no statistically significant difference in maternal and paternal age, maternal gravity and parity, number of previous ART attempts, concentration or motility of retrieved sperm, number of oocytes retrieved, fertilization rate, or number of embryos transferred between couples who did and did not achieve pregnancy. No miscarriages occurred. All 12 pregnancies resulted in the delivery of healthy children.

CONCLUSION(S)

The percentage of TUNEL-positive cells is lower in testicular sperm for oligospermic men who have abnormal ejaculated sperm DNA fragmentation. The use of testicular sperm for ICSI was associated with a 50% pregnancy and live-birth rate for couples who had previously failed one or more IVF-ICSI cycles with ejaculated sperm. No other clinical predictors of successful pregnancies after the use of surgically retrieved sperm could be identified. In men with elevated TUNEL-positive ejaculated sperm and failed ART, TESE may be considered.

A novel approach to normal responder patient with repeated implantation failures--a case report

We describe a case of normal responder patients with repeated implantation failure who was offered the combination of the ultrashort GnRH-ag/ GnRH-ant COH protocol, followed by endometrial injury and a subsequent natural cycle frozen-thawed embryos transfer. The patient conceived following the natural FET cycle that was supported by luteal daily progesterone, with the additional single injection of HCG and GnRH-agonist, on day of ET and 4 days later, respectively. This combined approach seems to be a valuable tool in the armamentarium for treating normal responder patients with repeated implantation failures and should be further examined in large randomized controlled trials.

Management of poor responders in IVF: is there anything new?

Despite the fact that in the last two decades an enormous number of papers on the topic of poor ovarian response have been published in the literature, so far it has been impossible to identify any efficient treatment to improve the ovarian response and the clinical outcome of this group of patients. The incidence of poor ovarian responders among infertile women has been estimated at 9–24% but according to recent reviews, it seems to have slightly increased. The limitation in quantifying the incidence of these patients among the infertile population is due to the difficulty of a clear definition in literature. A recent paper by the Bologna ESHRE working group on poor ovarian response has been the first real attempt to find a common definition. Current literature proposes new risk factors which could be the cause of a reduction in ovarian reserve, which also includes genetic factors. This represents the first necessary step towards finding applicable solutions for these patients. To date, there is a substantial lack of literature that identifies an ideal protocol for these patients. The use of the “Bologna criteria” and the introduction of long acting gonadotropin in clinical practice have given rise to new promising stimulation protocols for this group of patients.

Should zygote intrafallopian transfer be offered to all patients with unexplained repeated in-vitro fertilization cycle failures?

BACKGROUND

One of the suggest strategy for patients with repeated implantation failure (RIF) is zygote intrafallopian transfer (ZIFT). However, no data exist regarding to the issue of when and under which circumstances should ZIFT be offered to patients with RIF? We therefore aimed to examine whether repeated implantation failure (RIF) patients characteristics or their previous controlled ovarian hyperstimulation (COH) variables may differentiate between those who will conceive following a ZIFT cycle and those who will not.

METHODS

Forty seven consecutive women admitted to our IVF unit during a 7 year period, who underwent ZIFT for RIF, were included. Ovarian stimulation characteristics, number of oocytes retrieved and number and quality of zygotes/embryos transferred were assessed and compared between the ZIFT cycle and the previous IVF/ICSI cycle and between those who conceived following the ZIFT cycle and those who did not.

RESULTS

Twelve clinical pregnancies (clinical pregnancy rate- 25.5%) were recorded following the ZIFT cycle. Those who benefit from ZIFT were young patients (≤31 yrs), who underwent ≤6 cycle attempts, yielding over eight 2PN embryos with low (≤0.4) ratio of number of top-quality embryos to total 2PN embryos. Moreover, in those destined for a ZIFT cycle, only those with >7 2PN embryo should undergo a transfer of at least five 2PN embryos.

CONCLUSIONS

Further large prospective studies are needed to identify the specific characteristics of RIF women who may benefit from ZIFT.

Implantation in assisted reproduction: a look at endometrial receptivity

Implantation failure in assisted reproduction is thought to be mainly due to impaired uterine receptivity. With normal uterine anatomy, changes in endocrine profile during ovarian stimulation and medical conditions of the mother (i.e. thrombophilia and abnormal immunological response) could result in a non-receptive endometrium. High oestradiol concentrations during ovarian stimulation lead to premature progesterone elevation, causing endometrial advancement and hampering implantation, which can be overcome by a freeze-all approach and embryo transfer in natural cycles or by milder stimulation protocols. Patients with recurrent implantation failure (RIF) should be tested for inherited and acquired thrombophilias. Each patient should be individually assessed and counselled regarding therapy with low-molecular-weight heparin (LMWH). Empirical treatment with LMWH, aspirin or corticosteroids is not effective for women with RIF who have negative thrombophilic tests. If thrombophilic tests are normal, patients should be tested for immunological causes. If human leukocyte antigen dissimilarity is proven, treatment with intravenous immunoglobulin might be beneficial. Preliminary observational studies using intralipid infusion in the presence of increased natural killer cytotoxic activity are interesting but the proposed rationale is controversial and randomized controlled trials are needed. Hysteroscopy and/or endometrial scratching in the cycle preceding ovarian stimulation should become standard for patients with RIF.

Does a single endometrial biopsy regimen (S-EBR) improve ICSI outcome in patients with repeated implantation failure? A randomised controlled trial

OBJECTIVE

To evaluate the effect of a single endometrial biopsy regimen (S-EBR) in the cycle preceding the ICSI cycle in patients with repeated implantation failure.

STUDY DESIGN

This was a prospective randomized controlled trial which included two-hundred infertile women with a history of repeated implantation failure. The subjects were randomly divided into two groups. Group A subjects underwent hysteroscopy and endometrial scraping by Novak curette in the cycle preceding the ICSI cycle, while group B subjects underwent hysteroscopy without endometrial scraping. Implantation rate, clinical pregnancy rate, abortion rate and live birth rate were compared between both groups.

RESULTS

The number of retrieved oocytes in group A was 11.6 ± 3 and in group B was 11.6 ± 2.8 with no statistically significant difference (p=0.787). There were statistically significant differences regarding the implantation rate, the clinical pregnancy rate and live birth rate. The implantation rate in group A was 12% while in group B it was 7% (p=0.015), the clinical pregnancy rate was 32% in group A while it was only 18% in group B (p=0.034) and the live birth rate was 28% in group A while it was 14% in group B (p=0.024).

CONCLUSIONS

The single endometrial biopsy regimen (S-EBR) performed during hysteroscopy has statistically significant higher implantation rate, clinical pregnancy rate and live birth rate than hysteroscopy without endometrial scraping.

Assessment and treatment of repeated implantation failure (RIF)

Repeated implantation failure (RIF) is determined when embryos of good quality fail to implant following several in vitro fertilization (IVF) treatment cycles. Implantation failure is related to either maternal factors or embryonic causes. Maternal factors include uterine anatomic abnormalities, thrombophilia, non-receptive endometrium and immunological factors. Failure of implantation due to embryonic causes is associated with either genetic abnormalities or other factors intrinsic to the embryo that impair its ability to develop in utero, to hatch and to implant. New methods of time-lapse imaging of embryos and assessment of their metabolic functions may improve selection of embryos for transfer, and subsequent outcomes for IVF patients, as well as for those diagnosed with RIF. This review discusses the various causes associated with RIF and addresses appropriate treatments.

The efficacy of melatonin administration on oocyte quality

The aim of the study was to evaluate the efficacy of melatonin administration on oocyte quality in women underwent in vitro fertilization (IVF) cycles. Eighty-five women undergoing IVF cycles were randomized in two groups during IVF-embryo transfer (ET) procedure, 40 women with melatonin treatment (A) and 45 women without melatonin treatment (B). Primary endpoint was the number of morphologically mature oocytes retrieved (MII oocytes). Secondary endpoints were fertilization rate per number of mature oocytes, embryo quality and pregnancy rate. There were no differences between two groups according to age, and peak estradiol levels. The mean number of oocytes (15.33 vs. 14.27) and the mean number of mature oocytes did not differ between the two groups (12.63 vs. 10.94), whereas the percentage of mature oocytes (M2/oocytes retrieved) was significantly different in melatonin-treated group (p < 0.05). Fertilization rate (72.75 vs. 71.16) did not differ between the two groups. The mean number of class 1 embryos resulted higher in the group A (3.28 vs. 2.53) (p < 0.05). Clinical pregnancy rate was in tendency higher in the group treated with melatonin, although the differences did not reach statistical significance. Melatonin is likely to improve oocyte and embryo quality in women undergoing IVF or intracytoplasmic sperm insemination (ICSI).

Association of p53 polymorphism with ICSI/IVF failure and recurrent pregnancy loss

BACKGROUND

The p53 tumour suppressor gene is a well-known factor regulating apoptosis in a wide variety of cells. Alterations in the p53 gene are among the most common genetic changes in human cancers. Several polymorphisms of the p53 tumour suppressor gene have been associated with recurrent pregnancy loss (RPL).

AIMS

To evaluate the association of polymorphisms p53 codon 72 with the response to in vitro fertilisation (IVF) treatment and occurrence of repeated miscarriages.

METHODS

The homozygous and heterozygous genotypes and allelic frequencies of Arg and Pro p53 at codon 72 were identified by using polymerase chain reaction-restriction fragment length polymorphism technique in 70 infertile women with more than two IVF failures. Each comparison was made with 97 women experiencing RPL and 32 fertile women each with at least two healthy children as the control group.

RESULTS

The frequency of homozygous Pro/Pro genotypes was found significantly higher among the women with RPL than the other two groups (P = 0.041). Whereas, Arg/Arg genotype was significantly different in the recurrent implantation failure (RIF) group (P = 0.005).

CONCLUSION

It is concluded that p53 codon 72 polymorphism may serve as a susceptible factor affecting the chances of RPL and RIF.

Pregnancies and live births following ICSI with testicular spermatozoa after repeated implantation failure using ejaculated spermatozoa

The use of testicular spermatozoa for IVF/intracytoplasmic sperm injection (ICSI) is currently indicated exclusively for patients with azoospermia, since a favourable outcome is expected even when very few spermatozoa are present in the ejaculate. Here, a series of four couples with long-standing male factor infertility and multiple failed IVF/ICSI cycles are described. In all couples, the use of ejaculated spermatozoa for ICSI resulted in poor embryo quality and repeated implantation failure. Testicular sperm aspiration was performed in subsequent cycles, and testicular spermatozoa were used for ICSI. Embryo implantation and ongoing pregnancies/deliveries were achieved in all four couples. It is postulated that spermatozoa are subjected to post-testicular damage during sperm transport between the seminiferous tubules and epididymis, with the injection of damaged spermatozoa being the cause for repetitive IVF/ICSI failures. In selected patients, the use of testicular spermatozoa for IVF/ICSI should be considered, even when motile spermatozoa can be identified in the ejaculate.

Gamete cytogenetic study in couples with implantation failure: aneuploidy rate is increased in both couple members

PURPOSE

Implantation failure is known to be associated with an increased risk of aneuploidy in embryos, a situation leading to a pre-implantation genetic screening, not allowed in different countries like France. Our aim was to evaluate the gamete aneuploidy incidence in this context, using first polar body and spermatozoa aneuploidy screening.

METHODS

Three groups were considered: 11 couples with pregnancy obtained after IVF for female infertility (group 1); 20 couples with pregnancy obtained after IVF for male infertility (group 2); and 35 couples with implantation failure (group 3). In group 3, 28 couples treated by ICSI volunteered for first polar body analysis (PB1).

RESULTS

Spermatozoa aneuploidy rate was increased in groups 2 (1.6%) and 3 (2.1%) in comparison to group 1 (0.6%). PB1 aneuploidy rate was 35.4% in group 3. Finally, eight couples (32%) had no particular chromosomal risk in gametes, 15/25 (60%) presented an increased spermatic (>2%) or oocyte (>1/3) aneuploidy rate, and 2/25 (8%) had both.

CONCLUSION

Those results confirm that implantation failure has a heterogeneous origin, that gamete chromosome abnormality rate is one of the major contributing factors, and that 1st Polar body and spermatozoa aneuploidy screening or pre-implantation genetics screening may be indicated for these couples.

The effect of preimplantation genetic screening on the probability of live birth in young women with recurrent implantation failure; a nonrandomized parallel group trial

OBJECTIVE

The aim of this study was to evaluate the efficacy of preimplantation genetic screening (PGS) in women younger than 38 years and who had recurrent implantation failure (RIF).

STUDY DESIGN

A prospective nonrandomized parallel group study was performed in the assisted reproduction unit of a private tertiary care hospital. 140 infertile couples who had three or more previous failed cycles were included. Genetic counseling was given and couples who opted for another treatment cycle with PGS (n=54) formed the PGS group whereas couples who declined PGS formed the control group (n=86). In the PGS group, following FISH analysis for the detection of chromosomes 13, 16, 18, 21, 22, X and Y, only euploid embryos were transferred on day 5. In the control group embryo transfer was performed on day 3. Clinical pregnancy and live birth rates were compared. 95% confidence intervals for differences between the groups were calculated.

RESULTS

Baseline and treatment cycle characteristics were similar in both groups. In the PGS group, a mean number of two embryos were transferred; there were 8 clinical pregnancies (14.8%). The implantation rate was 11.9%. There were no miscarriages and the live birth rate was 14.8%. In the control group, a mean number of 2.7 embryos were transferred resulting in 23 pregnancies (26.7%). The implantation rate was 18.4%. There were 2 miscarriages and the live birth rate was 24.4%. The differences among the groups were not statistically significant.

CONCLUSION

The results suggest that this particular group of young patients with RIF may not benefit from PGS. However, PGS is a multistep procedure that is highly human dependent, and results may vary across laboratories.

Researching human oocyte cryopreservation: ethical issues

OBJECTIVE

To evaluate some ethical concerns related to the selection of participants for oocyte cryopreservation research.

DESIGN

Review of ethical issues related to human oocyte cryopreservation research.

SETTING

Academic medical center.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

A discussion of some ethical concerns surrounding selection of participants for oocyte cryopreservation research.

RESULT(S)

Human oocyte cryopreservation has the potential to expand reproductive options for infertile couples. Care needs to be taken, however, to carefully select participants in ways that maximizes benefits to them and to society and minimizes risks. Infertility programs can do so by trying to recruit women who stand to benefit the most from participating in oocyte cryopreservation protocols.

CONCLUSION(S)

Biomedical research is necessary to improve current medical therapies. Oocyte cryopreservation can increase the flexibility of assisted reproductive programs and offer hope to a significant number of infertile couples. Nonetheless, scientific research cannot be attentive only to the creation of new knowledge and new technologies; it also is inextricably tied to ethical considerations about the well-being of participants.

Two-year outcome after recurrent implantation failure: prognostic factors and additional interventions

Objectives

After recurrent implantation failure (RIF), empirical figures on further prospects are essential for counselling but difficult to estimate within single IVF centres due to high drop-out rates. Alternatively, couples referred to a tertiary unit for RIF were evaluated.

Materials and methods

Multi-centre 2-year observational trial of 1,174 eligible couples treated consecutively with adjuvant lymphocyte immunotherapy (LIT) in a university immunological department from 1999 to 2002 after three or more unsuccessful fresh embryo transfers. Acquisition of data was completed in 2005.

Results

With another 1.5 oocyte retrievals, delivery rate per couple depended on age (39.3% at <30 years, 16.9% at >39 years, P < 0.005). Prognosis was favourable when frozen embryo transfers had been conducted before (34.4 vs. 25.8%, P < 0.005). The outcome was slightly better in ICSI couples as compared to conventional IVF (31.0 vs. 24.8%, P < 0.05). Birth rates per fresh embryo transfer from the fourth to eighth retrieval were 17.4–18.3–15.0–12.9–12.9% (decline not significant). Apart from LIT, further additional interventions were given more often to couples who had had frozen embryo transfers before (49 vs. 40%, P < 0.005).

Conclusions

Female age and ovarian response are crucial for further IVF prognosis. Previous frozen embryo transfers indicate better chances. Couples with male factor infertility may benefit from intracytoplasmatic sperm injection (ICSI) because underlying female factors are less prevalent. Cycle rank had comparatively little impact. Additional interventions are preferentially offered to couples who have a favourable prognosis anyway. Their multiple use is common practice in RIF, but its value should be considered limited.

Müllerian inhibiting substance is an accurate marker of ovarian response in women of advanced reproductive age undergoing IVF

While multiple investigators have demonstrated that Müllerian inhibiting substance (MIS) concentration is an accurate marker of ovarian reserve, all previous reports have focused on patients aged 36 and younger. It remains to be seen if MIS concentration is a useful marker in patients with the highest prevalence of diminished ovarian reserve: those aged 37 and over. Day 2 MIS concentrations in patients aged 37 and over undergoing IVF were examined, and the predictive value of MIS concentration was compared to that of FSH and oestradiol concentration. Three groups of patients were studied: (i) patients who experienced cycle cancellation; (ii) patients who underwent oocyte retrieval; (iii) patients who were precluded from IVF due to elevated FSH concentrations. While FSH and oestradiol concentrations were statistically similar in groups 1 and 2, MIS concentrations were significantly lower in group 1. In group 2, MIS concentration positively correlated with the number of oocytes retrieved. In group 3, 91% had low or undetectable MIS concentrations. The results indicate that MIS concentration accurately predicts cycle cancellation that is belied by normal FSH and oestradiol measurements, and has a better correlation with the number of oocytes retrieved than FSH and oestradiol measurements.

Timing intra-Fallopian transfer procedures

With the gradual decline in the use of zygote intra-Fallopian transfer (ZIFT), current practice is to offer ZIFT almost exclusively to patients with repeated implantation failure (RIF). For practical reasons, the procedure is sometimes deferred by 1 day and embryo intra-Fallopian transfer (EIFT) is performed. The aim of the present study was to compare the reproductive outcome of ZIFT versus EIFT. In a retrospective analysis, 176 patients who failed in 7.65 +/- 3.7 previous IVF cycles underwent 200 ZIFT and 73 EIFT procedures. Implantation and live birth rates were compared for both groups. Patients in both groups were found comparable for demographic and clinical parameters. Similar numbers of oocytes were retrieved and fertilized in both groups, and 5.2 +/- 1.2 zygotes/embryos were transferred. Implantation and live birth rates (10.5 and 26.5% versus 10.9 and 24.7% for ZIFT and EIFT respectively) were comparable. It is concluded that tubal transfer of zygotes and day-2 cleavage stage embryos are equally effective.

Progesterone supplementation to prevent recurrent miscarriage and to reduce implantation failure in assisted reproduction cycles

Implantation failure has been questioned for many cases of recurrent miscarriage and unsuccessful assisted reproduction. The exact cause of implantation failure is not known, but luteal phase defect is encountered in many of these cases. Consequently, women with recurrent miscarriages have been treated with progesterone supplementation with various degrees of success, and a recent meta-analysis has shown trends for improved live birth rates in those women. Progesterone probably acts as an immunological suppressant blocking T-helper (Th)1 activity and inducing release of Th2 cytokines. Numerous studies have confirmed that ovarian stimulation used in assisted reproduction is associated with luteal phase insufficiency, even when gonadotrophin-releasing hormone antagonists are used. In those patients, advanced endometrial histological maturity and a decrease in the concentration of cytoplasmic progesterone receptors are observed. Progesterone supplementation results in a trend towards improved ongoing and clinical pregnancy rates, except in patients treated with human menopausal gonadotrophin-only regimens, in whom ongoing pregnancy rates increase significantly. More randomized controlled trials are needed to increase the power of the currently available meta-analyses to further evaluate progesterone supplementation in both conditions.

Towards better quality research in recurrent implantation failure: standardizing its definition is the first step

Recurrent implantation failure is a frustrating condition for clinicians and patients alike. The number of potential therapies offered to patients in order to overcome this problem is increasing, and more research is needed to establish which of those treatment options is truly beneficial. Improved understanding of their value is more likely if the same definition of recurrent implantation failure is used across future studies. In this article, the inconsistency present in current literature is examined and the case is argued for a standardized definition for the condition.

Firm embryo transfer catheters for assisted reproduction: a systematic review and meta-analysis using direct and adjusted indirect comparisons

A systematic review of published evidence on firm embryo transfer catheters is presented. Extensive searches were conducted for full-text manuscripts, abstracts, ongoing and unpublished trials. Direct and adjusted indirect comparisons were undertaken, where appropriate. Twenty-six randomized controlled trials comparing embryo transfer catheters were identified. Only two trials (314 transfers) compared different firm embryo catheters. Using direct comparison, both the Tom Cat and Tefcat catheters demonstrated statistically significant increased chances of clinical pregnancy compared with the Tight Difficult Transfer (TDT) catheter (P=0.007; OR=3.67, 95% CI=1.48-9.10 and P<0.0001; OR=4.71, 95% CI=2.34-9.48 respectively). The implantation rates were also higher with the Tom Cat and Tefcat catheters than the TDT catheter (P=0.005; OR=3.67, 95% CI=1.48-9.10 and P<0.00001; OR=4.29, 95% CI=2.45-7.50 respectively). Using adjusted indirect comparison, Tom Cat and Tefcat catheters were compared, and shown to have similar pregnancy and implantation rates (OR=0.99; 95% CI=-0.87-1.79 and OR=0.86; 95% CI=-0.77-1.35). In conclusion, both Tom Cat and Tefcat catheters give better outcomes than the TDT catheter, but are similar to each other.

Safety of IVF under anticoagulant therapy in patients at risk for thrombo-embolic events

The objective of this study was to assess the safety of induction of ovulation and oocyte retrieval in patients at risk of thrombosis, necessitating treatment with anticoagulants. Twenty-four patients considered as high risk for a thromboembolic event underwent 73 IVF cycles and 68 oocyte retrieval procedures, and were treated concomitantly with anticoagulation therapy (low molecular weight heparin; LMWH). A subgroup of five patients considered at especially high risk for thrombosis was isolated. These patients were prepared for oocyte retrieval using a controlled spontaneous cycle. All these patients were programmed exclusively for surrogacy. Nineteen women underwent 49 cycles of ovulation induction with gonadotrophins. The average peak oestradiol concentration was 1791 +/- 1420 pg/ml with an average of 13.5 +/- 8.4 oocytes retrieved in each cycle. The five patients from the very high risk group underwent 24 cycles: the average peak oestradiol concentration was 163 +/- 98 pg/ml. In 18, an egg was retrieved and in 14, fertilization was achieved. No bleeding or thromboembolic complications were noted during treatment of both groups of patients. It is concluded that during induction of ovulation in patients at risk for thrombosis, the introduction of LMWH as a cycle protective treatment was not associated with any medical complication. The use of a controlled spontaneous cycle with LMWH is suggested in very high risk patients.

Future directions of failed implantation and recurrent miscarriage research

Recurrent implantation failure is today the major reason for women completing several IVF/intracytoplasmic sperm injection attempts without having achieved a child, and is probably also the explanation for many cases of unexplained infertility. Most causes of recurrent miscarriage are still poorly elucidated, but from a theoretical point of view recurrent implantation failure and recurrent miscarriage are suggested to have partly overlapping causes. Recent research has indeed documented that both syndromes can be caused by the same embryonic chromosomal abnormalities and the same maternal endocrine, thrombophilic and immunological disturbances. Consequently, many treatments attempting to normalize these abnormalities have been tested or are currently used in women with both recurrent implantation failure and recurrent miscarriage. However, no treatment for the two syndromes is at the moment sufficiently documented to justify its routine use. In this review, an overview is given regarding present knowledge about causes that may be common for recurrent implantation failure and recurrent miscarriage, and suggestions are put forward for future research that may significantly improve understanding and treatment options for the syndromes.

Uterine natural killer cells, implantation failure and recurrent miscarriage

Uterine natural killer (uNK) cells are the most abundant leukocytes in preimplantation endometrium and early pregnancy decidua. Maternal uNK cells are adjacent to, and have the ability to interact directly with, fetal trophoblasts. uNK cells can secrete an array of cytokines that are important in angiogenesis and thus placental development and the establishment of pregnancy. Increased numbers of uNK cells have been associated with reproductive failure. The number of preimplantation uNK cells has been reduced with prednisolone. However, despite these exciting advances in understanding of the uNK cells, considerably more work needs to be done to establish a specific role for uNK cells and to use uNK cells as a test of malfunctioning endometrium and the basis for future treatment for reproductive failure.

Sequential transfer of day 3 embryos and blastocysts after previous IVF failures despite adequate ovarian response

The purpose of this study was to compare IVF outcome following sequential embryo transfer (ET) with that following the transfer of early cleavage embryos among patients with previous multiple IVF failures but adequate ovarian response. A retrospective matched case-control analysis was made of the medical files of 66 women who underwent sequential transfer of day 3 embryos and blastocysts in the Chaim Sheba Medical Centre between January 1999 and May 2004. The control group included 117 matched women who underwent embryo transfer on day 3 only. Sequential transfer of embryos in women resulted in a pregnancy rate of 30.3% (20/66) compared with 17.1% (20/117) following day 3 ET (P < 0.05). Multiple pregnancies (most of them twins) were significantly more common in women undergoing sequential transfer (10/20 versus 2/20; P < 0.02). Sequential transfer of embryos may be indicated for women with repeated IVF cycles, but the number of embryos transferred must be limited in order to prevent multifetal gestations. More data are needed to support this approach.

Effect of fragment removal on blastocyst formation and quality of human embryos

Blastomere fragmentation is one of the most significant defects in cleaving embryos. Scientists believed that removing the fragments was a possible way to reduce their unwanted effects. This hypothesis has been tested in some studies in which the development of human fragmented embryos was followed in vivo after all fragments were removed, but little is known about the potential for in-vitro development of such embryos, which is the subject of the present study. For this purpose, 4-6 cell surplus human embryos were scored according to the degree and pattern of fragmentation into four grades, allocated into two groups of control and fragmentation removal (experimental) and cultured sequentially. At the end of day 6 of culture, in the experimental group especially in grade IV blastocyst rate, size and number of blastomeres in each blastocyst were all improved compared with those of the control group (42.3 versus 20.0%; 19,205.7 +/- 1060.3 versus 15,825.9 +/- 448.7 microm(2) and 100.14 +/- 13.48 versus 63.75 +/- 19.79 respectively, P < 0.05). In the grade IV embryos, apoptotic index was also significantly reduced after embryo fragmentation removal (3.40 +/- 0.88 versus 22.99 +/- 4.45, P < 0.05). In conclusion, fragmentation removal had a positive effect on human fragmented embryos and produced the best quality blastocysts.

Endometriosis, recurrent miscarriage and implantation failure: is there an immunological link?

Endometriosis is more frequently diagnosed in patients with infertility than in a normal population. The goal of this paper is to give an overview of the clinical and fundamental evidence for a possible link between endometriosis and (recurrent) miscarriage or implantation failure after treatment with assisted reproductive technology. According to the literature, there is insufficient evidence for an association between endometriosis and (recurrent) miscarriage, but there is, however, epidemiological evidence to support the link between endometriosis and recurrent implantation failure after assisted reproduction. This can possibly be explained by alterations in humoral and cell-mediated immunity in women with endometriosis. Humoral immunological changes include increased formation of antibodies against endometrial antigens, anti-laminin-1 auto-antibodies and other auto-immune antibodies (e.g. antiphospholipid). Cell-mediated immunological changes include alterations in peritoneal and follicular fluid immune cells and cytokines. The possible negative effect of these immunological changes on folliculogenesis, ovulation, oocyte quality, early embryonic development and implantation in women with endometriosis suggests that infertility in endometriosis patients may be related to alterations within the follicle or oocyte, resulting in embryos with decreased ability to implant.

Role of embryo quality in predicting early pregnancy loss following assisted reproductive technology

Early pregnancy loss (EPL) significantly reduces the initial success rate of assisted reproduction treatments and increases the psychological burden on the patient. The aim of the current study was to investigate the association between embryo quality and EPL in IVF. A retrospective study of 1471 women undergoing IVF between July 2000 and October 2004 was performed. Multivariate logistic regression models evaluated the effect on EPL of the woman's age, type and cause of infertility, endometrial thickness on the day of oocyte retrieval, performance of intracytoplasmic sperm injection, number of transferred embryos, embryo quality as assessed by the number of blastomeres in the leading transferred embryo at day 3, and the percentage of fragmentation. The 2902 oocyte retrieval-embryo transfer cycles resulted in 816 pregnancies (28.1%; 705 women) constituting the study cohort. Of these, 259 pregnancies (31.7%) ended in EPL and 557 (68.3%) in ongoing pregnancies. EPL risk was significantly associated with advanced (>35 years) maternal age (OR=1.53; 95% CI 1.12-2.09) and five or fewer blastomeres in the leading embryo transferred at day 3 (OR=1.82; 95% CI 1.16-2.85). In conclusion, the quality of transferred embryos, as assessed by the total number of blastomeres in the leading transferred embryo, and maternal age are predictors of EPL.

Which patients with recurrent implantation failure after IVF benefit from PGD for aneuploidy screening?

Patients with recurrent IVF failure are defined as patients who are younger than 37 years and who had at least three consecutive unsuccessful IVF/intracytoplasmic sperm injection (ICSI) cycles with good quality embryos. These patients might be predisposed to chromosome errors in their embryos and therefore might benefit from preimplantation genetic diagnosis for aneuploidy screening (PGD-AS). This technique is, however, expensive and some normal embryos might be lost due to the error rate. The aim of this retrospective study was to define those patients who would benefit most from it. One hundred and twenty-one first PGD-AS cycles for recurrent IVF failure were analysed. The aneuploidy rate, 'no embryo transfer' rate, live birth rate per embryo transfer and implantation rate were respectively 48.3, 22.3, 29.7 and 19.5%. A multivariate logistic regression analysis gave us a predictive model demonstrating that to have a 90% probability of having an embryo transfer after PGD-AS, the patient should have at least 10 mature oocytes, eight normally fertilized oocytes and six embryos for biopsy. This study suggests that most patients with recurrent IVF failure may benefit from PGD-AS. Future studies, however, should more strictly define this heterogeneous group of patients, so that comparison is easier.