Impact of preimplantation genetic diagnosis on IVF outcome in implantation failure patients

Risk of embryo aneuploidy is affected by the increase in sperm DNA damage in recurrent implantation failure patients under ICSI-CGH array cycles

This study investigates the relationship between sperm DNA damage in recurrent implantation failure (RIF) patients treated with comparative genomic hybridisation array-intracytoplasmic sperm injection (CGH array-ICSI) cycles and embryo aneuploidy screening. Forty-two RIF couples were selected. Sperm DFI was measured using TUNEL by flow cytometry. Two groups were defined as follows: (i) sperm with high DFI (> 20%); and (ii) low DFI (< 20%). Semen parameters, total antioxidant capacity (TAC), and malondialdehyde formation (MDA) were also measured in both groups. Following oocyte retrieval and ICSI procedure, blastomere biopsy was performed at the 4th day of development and evaluated with CGH-array. The high DFI group had a significant (p = 0.04) increase in the number of aneuploid embryos compared to the low one. According to Poisson regression results, the risk of aneuploidy embryos in the high DFI group was 55% higher than the low DFI group (RR = 1.55; 95% CI = 1.358-1.772). Moreover, chromosomal analysis showed an elevation of aneuploidy in chromosomes number 16 and 20 in the high DFI group compared to the low DFI group (p < 0.05). The high DFI in RIF patients may significantly affect the risk of aneuploidy embryos. Therefore, embryo selection by CGH-array should be considered for couples with high levels of sperm DNA fragmentation.

Peri-implantation glucocorticoid administration for assisted reproductive technology cycles

BACKGROUND

The use of peri-implantation glucocorticoids has been advocated to improve embryo implantation during assistive reproductive technology (ART) cycles such as in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). It has been proposed that glucocorticoids may improve the intrauterine environment by acting as immunomodulators to reduce the uterine natural killer (NK) cell count and activity, normalising the cytokine expression profile in the endometrium and by suppression of endometrial inflammation.

OBJECTIVES

To evaluate the effectiveness and safety of glucocorticoids versus no glucocorticoids administered around the time of anticipated implantation in women undergoing IVF or ICSI.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group specialised register, CENTRAL (now also containing output from two trial registers and CINAHL), MEDLINE and Embase, on 20 December 2021, together with reference checking, contact with experts in the field and relevant conference proceedings to identify additional studies. This review is an update of the review first published in  2007 and last updated in 2012.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the efficacy of supplementary systemic administration of glucocorticoids in the peri-implantation period with a placebo or no glucocorticoids in subfertile women undergoing IVF or ICSI were included.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live birth rate and multiple pregnancy.

MAIN RESULTS

We included 16 RCTs (2232 couples analysed). We are uncertain whether glucocorticoids improved live birth rates (odds ratio (OR) 1.37, 95% confidence interval (CI) 0.69 to 2.71; 2 RCTs, n = 366; I2 = 7%; very low-certainty evidence). This suggests that if the chance of live birth following no glucocorticoids/placebo is assumed to be 9%, the chance following glucocorticoids would be between 6% and 21%. We are also uncertain whether there was a difference between peri-implantation glucocorticoids on multiple pregnancy rates per couple (OR 0.86, 95% CI 0.33 to 2.20; 4 RCTs, n = 504; I2 = 53%; very low-certainty evidence). The I2 of 53% may represent moderate statistical heterogeneity and results have to be interpreted with caution. With regard to pregnancy rates, we are uncertain whether there was a difference between ongoing pregnancy rates after glucocorticoids versus no glucocorticoids/placebo (OR 1.19, 95% CI 0.80 to 1.76; 3 RCTs, n = 476; I2 = 0%; very low-certainty evidence) and clinical pregnancy rates after glucocorticoids versus no glucocorticoids/placebo (OR 1.17, 95% CI 0.95 to 1.44; 13 RCTs, n = 1967; I2 = 0%; low-certainty evidence). This suggests that if the chance of clinical pregnancy following no glucocorticoids/placebo is assumed to be 25%, the chance following glucocorticoids would be between 24% and 32%. Furthermore, we are also uncertain whether peri-implantation glucocorticoids influenced miscarriage rates per couple (OR 1.09, 95% CI 0.63 to 1.87; 6 RCTs, n = 821; I2 = 0%; very low-certainty evidence), the incidence of ectopic pregnancies per couple (OR 2.28, 95% CI 0.33 to 15.62; 3 RCTs, n = 320; I2 = 0%; very low-certainty evidence) and ovarian hyperstimulation syndrome (OHSS) per couple (OR 1.07, 95% CI 0.60 to 1.90; 3 RCTs, n = 370; I2 = 0%; very low-certainty evidence) compared to no glucocorticoids/placebo. The evidence was very low to low certainty: the main limitations were serious risk of bias due to poor reporting of study methods, and serious imprecision.

AUTHORS' CONCLUSIONS

Overall, there was insufficient evidence that administration of peri-implantation glucocorticoids in IVF/ICSI cycles influenced clinical outcomes. These findings were limited to the routine use of glucocorticoids in subfertile women undergoing IVF or ICSI.

The clinical efficiency of transcriptome-based endometrial receptivity assessment (Tb-ERA) in Chinese patients with recurrent implantation failure (RIF): A study protocol for a prospective randomized controlled trial

Background

Today, approximately 10% of participants in assisted reproductive technology (ART) are defined as having recurrent implantation failure (RIF). Recent studies show that endometrial receptivity array can improve pregnancy and implantation rates by nearly 20% in women with RIF. However, these studies are limited, with little published data in the Chinese population. Recently, we have established a transcriptome-based endometrial receptivity assessment (Tb-ERA) method of predicting the endometrial window of implantation (WOI) using transcriptome-profiling data of different phases of the menstrual cycle from healthy fertile Chinese women by RNA-Seq. It is meaningful to conduct a randomized controlled trial (RCT) to assess the clinical efficiency of Tb-ERA in Chinese patients with RIF.

Methods

In this RCT, a total of 200 RIF patients will be recruited and randomized into 2 groups. Patients in the Tb-ERA group will undergo a Tb-ERA test, after which embryo transfer time will be adjusted according to Tb-ERA results and embryo transfer will be performed again in the next cycle. Patients in the control group will not receive any interventions until the next transfer cycle. We will perform statistical analysis on both groups at the primary endpoint (clinical-pregnancy rate) and at secondary endpoints (rate of WOI displacement, embryo implantation, biochemical pregnancy, early abortion, and ectopic pregnancy). Implications: This study aims to evaluate the effectiveness of our Tb-ERA test in Chinese RIF patients and to determine that whether Tb-ERA could improve the clinical-pregnancy rate in these RIF patients.

Trial registration

NCT04497558, registered August 4, 2020.

Next-Generation Sequencing (NGS)-Based Preimplantation Genetic Testing for Aneuploidy (PGT-A) of Trophectoderm Biopsy for Recurrent Implantation Failure (RIF) Patients: a Retrospective Study

Recurrent implantation failure (RIF) is an intrigue condition during in vitro fertilization (IVF) cycles or intracytoplasmic sperm injection (ICSI) treatments. The purpose of this retrospective study is to explore the value of next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) of trophectoderm biopsy in the clinical outcomes for RIF patients with advanced age. A total of 265 RIF patients, who underwent 346 oocyte retrieval cycles and 250 PGT-A cycles, were classified as two groups according to the female age, including < 38 and ≥ 38 years old groups. The two groups were statistically comparable in baseline characteristics. The component of aneuploid embryos was significantly higher in advanced age group than in younger age group (68.9 vs 39.9%, P < 0.001). But there were no statistically significant differences in pregnancy rate (43.5 vs 64.7%), clinical pregnancy rate (39.1 vs 48.0%), implantation rate (39.1 vs 51.0%), and miscarriage rate (4.3 vs 7.8%) per embryo transfer (ET) between the two groups. Results suggest that the embryo-related factor plays a crucial role in RIF. Maternal age does not influence the implantation potential of euploid blastocysts. The NGS-based PGT-A involving trophectoderm biopsy is valuable for RIF patients of advanced age by improving their clinical outcomes. In conclusion, the NGS-based PGT-A involving trophectoderm biopsy may represent a valuable supplement to the current RIF management. Nonetheless, these findings should be further validated in a well-designed randomized controlled trial.

Preimplantation genetic testing for aneuploidies (abnormal number of chromosomes) in in vitro fertilisation

BACKGROUND

In in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI), selection of the most competent embryo(s) for transfer is based on morphological criteria. However, many women do not achieve a pregnancy even after 'good quality' embryo transfer. One of the presumed causes is that such morphologically normal embryos have an abnormal number of chromosomes (aneuploidies). Preimplantation genetic testing for aneuploidies (PGT-A), formerly known as preimplantation genetic screening (PGS), was therefore developed as an alternative method to select embryos for transfer in IVF. In PGT-A, the polar body or one or a few cells of the embryo are obtained by biopsy and tested. Only polar bodies and embryos that show a normal number of chromosomes are transferred. The first generation of PGT-A, using cleavage-stage biopsy and fluorescence in situ hybridisation (FISH) for the genetic analysis, was demonstrated to be ineffective in improving live birth rates. Since then, new PGT-A methodologies have been developed that perform the biopsy procedure at other stages of development and use different methods for genetic analysis. Whether or not PGT-A improves IVF outcomes and is beneficial to patients has remained controversial.

OBJECTIVES

To evaluate the effectiveness and safety of PGT-A in women undergoing an IVF treatment.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers in September 2019 and checked the references of appropriate papers.

SELECTION CRITERIA

All randomised controlled trials (RCTs) reporting data on clinical outcomes in participants undergoing IVF with PGT-A versus IVF without PGT-A were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed risk of bias, and extracted study data. The primary outcome was the cumulative live birth rate (cLBR). Secondary outcomes were live birth rate (LBR) after the first embryo transfer, miscarriage rate, ongoing pregnancy rate, clinical pregnancy rate, multiple pregnancy rate, proportion of women reaching an embryo transfer, and mean number of embryos per transfer.

MAIN RESULTS

We included 13 trials involving 2794 women. The quality of the evidence ranged from low to moderate. The main limitations were imprecision, inconsistency, and risk of publication bias. IVF with PGT-A versus IVF without PGT-A with the use of genome-wide analyses Polar body biopsy One trial used polar body biopsy with array comparative genomic hybridisation (aCGH). It is uncertain whether the addition of PGT-A by polar body biopsy increases the cLBR compared to IVF without PGT-A (odds ratio (OR) 1.05, 95% confidence interval (CI) 0.66 to 1.66, 1 RCT, N = 396, low-quality evidence). The evidence suggests that for the observed cLBR of 24% in the control group, the chance of live birth following the results of one IVF cycle with PGT-A is between 17% and 34%. It is uncertain whether the LBR after the first embryo transfer improves with PGT-A by polar body biopsy (OR 1.10, 95% CI 0.68 to 1.79, 1 RCT, N = 396, low-quality evidence). PGT-A with polar body biopsy may reduce miscarriage rate (OR 0.45, 95% CI 0.23 to 0.88, 1 RCT, N = 396, low-quality evidence). No data on ongoing pregnancy rate were available. The effect of PGT-A by polar body biopsy on improving clinical pregnancy rate is uncertain (OR 0.77, 95% CI 0.50 to 1.16, 1 RCT, N = 396, low-quality evidence). Blastocyst stage biopsy One trial used blastocyst stage biopsy with next-generation sequencing. It is uncertain whether IVF with the addition of PGT-A by blastocyst stage biopsy increases cLBR compared to IVF without PGT-A, since no data were available. It is uncertain if LBR after the first embryo transfer improves with PGT-A with blastocyst stage biopsy (OR 0.93, 95% CI 0.69 to 1.27, 1 RCT, N = 661, low-quality evidence). It is uncertain whether PGT-A with blastocyst stage biopsy reduces miscarriage rate (OR 0.89, 95% CI 0.52 to 1.54, 1 RCT, N = 661, low-quality evidence). No data on ongoing pregnancy rate or clinical pregnancy rate were available. IVF with PGT-A versus IVF without PGT-A with the use of FISH for the genetic analysis Eleven trials were included in this comparison. It is uncertain whether IVF with addition of PGT-A increases cLBR (OR 0.59, 95% CI 0.35 to 1.01, 1 RCT, N = 408, low-quality evidence). The evidence suggests that for the observed average cLBR of 29% in the control group, the chance of live birth following the results of one IVF cycle with PGT-A is between 12% and 29%. PGT-A performed with FISH probably reduces live births after the first transfer compared to the control group (OR 0.62, 95% CI 0.43 to 0.91, 10 RCTs, N = 1680, I² = 54%, moderate-quality evidence). The evidence suggests that for the observed average LBR per first transfer of 31% in the control group, the chance of live birth after the first embryo transfer with PGT-A is between 16% and 29%. There is probably little or no difference in miscarriage rate between PGT-A and the control group (OR 1.03, 95%, CI 0.75 to 1.41; 10 RCTs, N = 1680, I² = 16%; moderate-quality evidence). The addition of PGT-A may reduce ongoing pregnancy rate (OR 0.68, 95% CI 0.51 to 0.90, 5 RCTs, N = 1121, I² = 60%, low-quality evidence) and probably reduces clinical pregnancies (OR 0.60, 95% CI 0.45 to 0.81, 5 RCTs, N = 1131; I² = 0%, moderate-quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient good-quality evidence of a difference in cumulative live birth rate, live birth rate after the first embryo transfer, or miscarriage rate between IVF with and IVF without PGT-A as currently performed. No data were available on ongoing pregnancy rates. The effect of PGT-A on clinical pregnancy rate is uncertain. Women need to be aware that it is uncertain whether PGT-A with the use of genome-wide analyses is an effective addition to IVF, especially in view of the invasiveness and costs involved in PGT-A. PGT-A using FISH for the genetic analysis is probably harmful. The currently available evidence is insufficient to support PGT-A in routine clinical practice.

Preimplantation Genetic Testing: Where We Are Today

BACKGROUND

Preimplantation genetic testing (PGT) is widely used today in in-vitro fertilization (IVF) centers over the world for selecting euploid embryos for transfer and to improve clinical outcomes in terms of embryo implantation, clinical pregnancy, and live birth rates.

METHODS

We report the current knowledge concerning these procedures and the results from different clinical indications in which PGT is commonly applied.

RESULTS

This paper illustrates different molecular techniques used for this purpose and the clinical significance of the different oocyte and embryo stage (polar bodies, cleavage embryo, and blastocyst) at which it is possible to perform sampling biopsies for PGT. Finally, genetic origin and clinical significance of embryo mosaicism are illustrated.

CONCLUSIONS

The preimplantation genetic testing is a valid technique to evaluated embryo euploidy and mosaicism before transfer.

Should we transfer poor quality embryos?

Background

To evaluate if it is safe and effective to transfer poor quality embryos.

Methods

It was a retrospective analysis using individual patient data with positive controls. All patients undergoing embryo transfers of poor quality embryos on day 3 or on day 5 as part of fresh In Vitro Fertilization (IVF) cycles performed between 2012 and 2016. This study assessed a total of 738 poor quality embryos from 488 IVF programs. 261 embryo transfers were performed on day 3 (402 embryos were transferred) and 227 on day 5 (336 embryos were transferred). Control group consisted of 9893 fair and good quality embryos from 5994 IVF programs. Outcome rates were compared with two-tailed Fisher exact test using fisher.test function in R software. 95% confidence intervals for proportions were calculated using the Clopper-Pearson method with binom.test function in R. The groups of patients with poor vs. good and fair quality embryos were compared by age, body mass index(BMI), number of oocytes, female and male main diagnosis, cycle type, controlled ovarian stimulation (COS) protocol, the starting day of gonadotropin administration, the starting dose of gonadotropins, the total dose of gonadotropins, the total number of days of gonadotropins administration, the starting day of gonadotropin-releasing hormone (GnRH) agonist administration, the total number of ampoules of GnRH-agonist used, day of the trigger of ovulation administration and the type of the trigger of ovulation using the Student’s t-test for interval variables and with the chi-square test for nominal variables.

Results

No significant differences in the implantation rate, clinical pregnancy rate, miscarriage rate, live births, and the number of children born were found between the groups of poor quality embryos transferred on day 3 and day 5. Though the implantation rate was lower for the group of poor quality embryos, than for the control (13.9% vs 37.2%), statistically significant differences between the proportion of implanted embryos which resulted in clinical pregnancies and live births in both groups were not observed (72% vs 78.2 and 55.8% vs 62.0% respectively).

Conclusion

Transfer of poor quality embryos at either day 3 or day 5 have a low potential for implantation, though those embryos which successfully implanted have the same potential for live birth as the embryos of fair and good quality. This study supports that it is safe to transfer poor quality embryos when they are the only option for fresh embryo transfer (ET).

Personalized Embryo Transfer Helps in Improving In vitro Fertilization/ICSI Outcomes in Patients with Recurrent Implantation Failure

Aims:

This study aims to compare clinical outcomes in patients of recurrent implantation failure (RIF), who had embryo transfer (ET) following a receptive (R) endometrial receptivity array (ERA) and a personalized embryo transfer (pET) after a nonreceptive (NR) ERA.

Settings and Design:

This was a retrospective observational study.

Study Period:

July 2013–September 2017.

Subjects and Methods:

Two hundred and forty-eight patients having unexplained RIF who underwent ERA test were included in the study. Clinical outcomes were compared between patients having a receptive (R) ERA and those having a NR ERA who underwent a pET-based on ERA.

Statistical Analysis Used:

Chi-square and t-test.

Results:

ERA predicted receptive (R) endometrium at P + 5 in 82.3% (204/248) patients and NR in 17.7% (44/248) patients. Average failed previous in vitro fertilization cycles were 3.67 ± 1.67 among receptive ERA patients and 4.09 ± 1.68 among NR ERA patients. Pregnancy rate (PR), clinical PR, implantation rate (IR), abortion rate (AR), ongoing pregnancy rate (OPR), and cumulative PR were comparable between patients having receptive ERA who had a routine Embryo Transfer (ET) and those with an NR ERA who underwent a pET.

Conclusions:

ERA is helpful in identifying the window of implantation (WOI) through genetic expressions of the endometrium to pinpoint embryo transfer timing. pET guided by ERA in patients of RIF with displaced WOI improves IRs and OPRs.

Recurrent Implantation Failure-update overview on etiology, diagnosis, treatment and future directions

Recurrent implantation failure (RIF) refers to cases in which women have had three failed in vitro fertilization (IVF) attempts with good quality embryos. The definition should also take advanced maternal age and embryo stage into consideration. The failure of embryo implantation can be a consequence of uterine, male, or embryo factors, or the specific type of IVF protocol. These cases should be investigated to determine the most likely etiologies of the condition, as this is a complex problem with several variables. There are multiple risk factors for recurrent implantation failure including advanced maternal age, smoking status of both parents, elevated body mass index, and stress levels. Immunological factors such as cytokine levels and presence of specific autoantibodies should be examined, as well as any infectious organisms in the uterus leading to chronic endometritis. Uterine pathologies such as polyps and myomas as well as congenital anatomical anomalies should be ruled out. Sperm analysis, pre-implantation genetic screening and endometrial receptivity should be considered and evaluated, and IVF protocols should be tailored to specific patients or patient populations. Treatment approaches should be directed toward individual patient cases. In addition, we suggest considering a new initial step in approach to patients with RIF, individualized planned activities to activate the brain's reward system in attempt to improve immunological balance in the body.

Implantation failure of endometrial origin: it is not pathology, but our failure to synchronize the developing embryo with a receptive endometrium

Repeated implantation failure (RIF) is an intriguing, massive failure of reproductive treatment in otherwise healthy women leading to the introduction of empirical adjuvant interventions that are costly, inefficient, and frustrating for our patients. In this article, we will try to convince the readers that RIF is neither a stigma nor a mysterious pathology but rather our failure to diagnose and properly synchronize the euploid blastocyst with the patient's personalized window of implantation.

Preimplantation genetic screening for all 24 chromosomes by microarray comparative genomic hybridization significantly increases implantation rates and clinical pregnancy rates in patients undergoing in vitro fertilization with poor prognosis

CONTEXT

A majority of human embryos produced in vitro are aneuploid, especially in couples undergoing in vitro fertilization (IVF) with poor prognosis. Preimplantation genetic screening (PGS) for all 24 chromosomes has the potential to select the most euploid embryos for transfer in such cases.

AIM

To study the efficacy of PGS for all 24 chromosomes by microarray comparative genomic hybridization (array CGH) in Indian couples undergoing IVF cycles with poor prognosis.

SETTINGS AND DESIGN

A retrospective, case-control study was undertaken in an institution-based tertiary care IVF center to compare the clinical outcomes of twenty patients, who underwent 21 PGS cycles with poor prognosis, with 128 non-PGS patients in the control group, with the same inclusion criterion as for the PGS group.

MATERIALS AND METHODS

Single cells were obtained by laser-assisted embryo biopsy from day 3 embryos and subsequently analyzed by array CGH for all 24 chromosomes. Once the array CGH results were available on the morning of day 5, only chromosomally normal embryos that had progressed to blastocyst stage were transferred.

RESULTS

The implantation rate and clinical pregnancy rate (PR) per transfer were found to be significantly higher in the PGS group than in the control group (63.2% vs. 26.2%, P = 0.001 and 73.3% vs. 36.7%, P = 0.006, respectively), while the multiple PRs sharply declined from 31.9% to 9.1% in the PGS group.

CONCLUSIONS

In this pilot study, we have shown that PGS by array CGH can improve the clinical outcome in patients undergoing IVF with poor prognosis.

Evidence of Selection against Complex Mitotic-Origin Aneuploidy during Preimplantation Development

Whole-chromosome imbalances affect over half of early human embryos and are the leading cause of pregnancy loss. While these errors frequently arise in oocyte meiosis, many such whole-chromosome abnormalities affecting cleavage-stage embryos are the result of chromosome missegregation occurring during the initial mitotic cell divisions. The first wave of zygotic genome activation at the 4-8 cell stage results in the arrest of a large proportion of embryos, the vast majority of which contain whole-chromosome abnormalities. Thus, the full spectrum of meiotic and mitotic errors can only be detected by sampling after the initial cell divisions, but prior to this selective filter. Here, we apply 24-chromosome preimplantation genetic screening (PGS) to 28,052 single-cell day-3 blastomere biopsies and 18,387 multi-cell day-5 trophectoderm biopsies from 6,366 in vitro fertilization (IVF) cycles. We precisely characterize the rates and patterns of whole-chromosome abnormalities at each developmental stage and distinguish errors of meiotic and mitotic origin without embryo disaggregation, based on informative chromosomal signatures. We show that mitotic errors frequently involve multiple chromosome losses that are not biased toward maternal or paternal homologs. This outcome is characteristic of spindle abnormalities and chaotic cell division detected in previous studies. In contrast to meiotic errors, our data also show that mitotic errors are not significantly associated with maternal age. PGS patients referred due to previous IVF failure had elevated rates of mitotic error, while patients referred due to recurrent pregnancy loss had elevated rates of meiotic error, controlling for maternal age. These results support the conclusion that mitotic error is the predominant mechanism contributing to pregnancy losses occurring prior to blastocyst formation. This high-resolution view of the full spectrum of whole-chromosome abnormalities affecting early embryos provides insight into the cytogenetic mechanisms underlying their formation and the consequences for human fertility.

Pregnancy outcome after blastocyst stage transfer comparing to early cleavage stage embryo transfer

Blastocyst transfer has been introduced as an alternative for improving the chance for in vitro fertilizations (IVF) implantation. The present study was to evaluate pregnancy rates when embryo transfer was performed either on day 2-3 (cleavage stage) or on day 4-5 (blastocyst stage). This randomized clinical trial included 118 infertile women. All the study subjects underwent controlled ovarian stimulation using a long protocol and randomized into two groups. BS group (n = 57), the culture was extended to day 5 (blastocyst stage) and in the CS-group (n = 61), embryo culture was continued to day 3 (cleavage stage). Ongoing pregnancies, abortion, implantation rate were evaluated. No significant differences were seen in the pregnancy rate between the two groups (33.3% in the BS group versus 27.9% in the CS group; p = 0.519). Abortion, implantation rate in two groups are not significant. Despite the lack of statistical difference between the two study groups, our data suggest that blastocyst transfer may be associated with a higher pregnancy and an overall better implantation rates. However, further studies with larger sample size are mandatory to confirm these findings.

Increased frequency of aneuploidy in long-lived spermatozoa

Aneuploidy commonly causes spontaneous abortions, stillbirths, and aneuploid births in humans. Notably, the majority of sex chromosome aneuploidies in live births have a paternal origin. An increased frequency of aneuploidy is also associated with male infertility. However, the dynamics and behavior of aneuploid spermatozoa during fertilization in humans have not been studied in detail. Therefore, we compared the frequency of aneuploidy and euploidy in live spermatozoa from normozoospermic men over a 3-day period. To assess the dynamics and behavior of aneuploid spermatozoa, we simultaneously evaluated sperm viability using the hypo-osmotic swelling test and sperm aneuploidy using fluorescence in situ hybridization. Whereas the frequency of viable euploid spermatozoa significantly decreased over 3 days, the frequency of viable spermatozoa with aneuploidy interestingly showed a time-dependent increase. In addition, spermatozoa with abnormal sex chromosomes survived longer. To compared with spermatozoa with other swelling patterns, those with tail-tip swelling patterns had a lower frequency of aneuploidy at all time points. This study revealed the novel finding that the frequency of aneuploid spermatozoa with fertilization capability significantly increased compared to that of euploid spermatozoa over 3 days, suggesting that aneuploid spermatozoa can survive longer than euploid spermatozoa and have a greater chance of fertilizing oocytes.

Is preimplantation genetic diagnosis the ideal embryo selection method in aneuploidy screening?

To select cytogenetically normal embryos, preimplantation genetic diagnosis (PGD) aneuploidy screening (AS) is used in numerous centers around the world. Chromosomal abnormalities lead to developmental problems, implantation failure, and early abortion of embryos. The usefulness of PGD in identifying single-gene diseases, human leukocyte antigen typing, X-linked diseases, and specific genetic diseases is well-known. In this review, preimplantation embryo genetics, PGD research studies, and the European Society of Human Reproduction and Embryology PGD Consortium studies and reports are examined. In addition, criteria for embryo selection, technical aspects of PGD-AS, and potential noninvasive embryo selection methods are described. Indications for PGD and possible causes of discordant PGD results between the centers are discussed. The limitations of fluorescence in situ hybridization, and the advantages of the array comparative genomic hybridization are included in this review. Although PGD-AS for patients of advanced maternal age has been shown to improve in vitro fertilization outcomes in some studies, to our knowledge, there is not sufficient evidence to use advanced maternal age as the sole indication for PGD-AS. PGD-AS might be harmful and may not increase the success rates of in vitro fertilization. At the same time PGD, is not recommended for recurrent implantation failure and unexplained recurrent pregnancy loss.

Comparative genomic hybridization selection of blastocysts for repeated implantation failure treatment: a pilot study

The aim of this study is to determine if the use of preimplantation genetic screening (PGS) by array comparative genomic hybridization (array CGH) and transfer of a single euploid blastocyst in patients with repeated implantation failure (RIF) can improve clinical results. Three patient groups are compared: 43 couples with RIF for whom embryos were selected by array CGH (group RIF-PGS), 33 couples with the same history for whom array CGH was not performed (group RIF NO PGS), and 45 good prognosis infertile couples with array CGH selected embryos (group NO RIF PGS). A single euploid blastocyst was transferred in groups RIF-PGS and NO RIF PGS. Array CGH was not performed in group RIF NO PGS in which 1-2 blastocysts were transferred. One monoembryonic sac with heartbeat was found in 28 patients of group RIF PGS and 31 patients of group NO RIF PGS showing similar clinical pregnancy and implantation rates (68.3% and 70.5%, resp.). In contrast, an embryonic sac with heartbeat was only detected in 7 (21.2%) patients of group RIF NO PGS. In conclusion, PGS by array CGH with single euploid blastocyst transfer appears to be a successful strategy for patients with multiple failed IVF attempts.

Preimplantation genetic screening using fluorescence in situ hybridization in patients with repetitive implantation failure and advanced maternal age: two randomized trials

OBJECTIVE

To evaluate the usefulness of preimplantation genetic screening (PGS) using fluorescence in situ hybridization (FISH) for two different indications: repetitive implantation failure (RIF) and advanced maternal age (AMA).

DESIGN

Two prospective, randomized controlled trials with patients allocated in two arms: blastocyst transfer on day 5 (group A) or PGS with transfer on day 5 (group B).

SETTING

University-affiliated private clinics.

PATIENT(S)

The RIF study included women <40 years with three or more failed IVF cycles without other known causal factors (91 patients). The AMA study included intracytoplasmic sperm injection patients aged between 41 and 44 (183 patients).

INTERVENTION(S)

In the PGS group, single-cell day 3 biopsy was performed with aneuploidy screening for chromosomes 13, 15, 16, 17, 18, 21, 22, X, and Y. In both the blastocyst transfer group and the PGS group, ET was performed on day 5.

MAIN OUTCOME MEASURE(S)

Live-birth rate per patient and per started cycle.

RESULT(S)

A significant increase in live-birth rates per patient was found in the PGS group compared with the blastocyst group for the AMA study (30/93 patients [32.3%] vs. 14/90 patients [15.5%]; odds ratio, 2.585; confidence interval, [1.262-5.295]). In the RIF study no significant differences were observed (23/48 patients [47.9%] vs. 12/43 patients [27.9%]).

CONCLUSION(S)

PGS with FISH was shown to be beneficial for the AMA group.

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.

Peri-implantation glucocorticoid administration for assisted reproductive technology cycles

BACKGROUND

In order to improve embryo implantation for in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles the use of glucocorticoids has been advocated. It has been proposed that glucocorticoids may improve the intrauterine environment by acting as immunomodulators to reduce the uterine natural killer (NK) cell count and normalise the cytokine expression profile in the endometrium and by suppression of endometrial inflammation.

OBJECTIVES

To investigate whether the administration of glucocorticoids around the time of implantation improved clinical outcomes in subfertile women undergoing IVF or ICSI when compared to no glucocorticoid administration.

SEARCH METHODS

The Cochrane Menstrual Disorders and Subfertility Group Trials Register (September 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (September 2011), MEDLINE (1966 to September 2011), EMBASE (1976 to September 2011), CINAHL (1982 to September 2011) and Science Direct (1966 to September 2011) were searched. Reference lists of relevant articles and relevant conference proceedings were handsearched.

SELECTION CRITERIA

All randomised controlled trials (RCTs) addressing the research question were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and quality of trials and extracted relevant data.

MAIN RESULTS

Fourteen studies (involving 1879 couples) were included. Three studies reported live birth rate and these did not identify a significant difference after pooling the (preliminary) results (OR 1.21, 95% CI 0.67 to 2.19). With regard to pregnancy rates, there was also no evidence that glucocorticoids improved clinical outcome (13 RCTs; OR 1.16, 95% CI 0.94 to 1.44). However, a subgroup analysis of 650 women undergoing IVF (6 RCTs) revealed a significantly higher pregnancy rate for women using glucocorticoids (OR 1.50, 95% CI 1.05 to 2.13). There were no significant differences in adverse events, but these were poorly and inconsistently reported.

AUTHORS' CONCLUSIONS

Overall, there was no clear evidence that administration of peri-implantation glucocorticoids in ART cycles significantly improved the clinical outcome. The use of glucocorticoids in a subgroup of women undergoing IVF (rather than ICSI) was associated with an improvement in pregnancy rates of borderline statistical significance and should be interpreted with care. These findings were limited to the routine use of glucocorticoids and cannot be extrapolated to women with autoantibodies, unexplained infertility or recurrent implantation failure. Further well designed randomised studies are required to elucidate the possible role of this therapy in well defined patient groups.

PGS-FISH in reproductive medicine and perspective directions for improvement: a systematic review

INTRODUCTION

Embryo selection can be carried out via morphological criteria or by using genetic studies based on Preimplantation Genetic Screening. In the present study, we evaluate the clinical validity of Preimplantation Genetic Screening with fluorescence in situ hybridization (PGS-FISH) compared with morphological embryo criteria.

MATERIAL AND METHODS

A systematic review was made of the bibliography, with the following goals: firstly, to determine the prevalence of embryo chromosome alteration in clinical situations in which the PGS-FISH technique has been used; secondly, to calculate the statistics of diagnostic efficiency (negative Likelihood Ratio), using 2 × 2 tables, derived from PGS-FISH. The results obtained were compared with those obtained from embryo morphology. We calculated the probability of transferring at least one chromosome-normal embryo when it was selected using either morphological criteria or PGS-FISH, and considered what diagnostic performance should be expected of an embryo selection test with respect to achieving greater clinical validity than that obtained from embryo morphology.

RESULTS

After an embryo morphology selection that produced a negative result (normal morphology), the likelihood of embryo aneuploidies was found to range from a pre-test value of 65% (prevalence of embryo chromosome alteration registered in all the study groups) to a post-test value of 55% (Confidence interval: 50-61), while after PGS-FISH with a negative result (euploid), the post-test probability was 42% (Confidence interval: 35-49) (p < 0.05). The probability of transferring at least one euploid embryo was the same whether 3 embryos were selected according to morphological criteria or whether 2, selected by PGS-FISH, were transferred. Any embryo selection test, if it is to provide greater clinical validity than embryo morphology, must present a LR-value of 0.40 (Confidence interval: 0.32-0.51) in single embryo transfer, and 0.06 (CI: 0.05-0.07) in double embryo transfer.

DISCUSSION

With currently available technology, and taking into account the number of embryos to be transferred, the clinical validity of PGS-FISH, although superior to that of morphological criteria, does not appear to be clinically relevant.

Implantation Failure, Etiology, Diagnosis and Treatment

Embryonic implantation is a complex interaction between the embryo and the endometrium. Despite great investigative effort this process is still obscure. Contrary to the great advancement in patient care, follicular recruitment, oocyte quality and aspiration, embryo quality, culture and cryopreservation, our understanding of the implantation process did not enhance as much, and the tools to intervene within this process are limited. The implantation of the transferred embryos still remains the major limiting factor in IVF. Here we will review the current literature on the maternal (uterine, hematologic, immunologic and others) and embryonic factors that are associated with repeated implantation failure (RIF) and describe the various therapeutic approaches to cope with them. In addition, we will present our conclusive recommendations on how to investigate and manage RIF based on the literature and our own experience.

Functional genomics of 5- to 8-cell stage human embryos by blastomere single-cell cDNA analysis

Blastomere fate and embryonic genome activation (EGA) during human embryonic development are unsolved areas of high scientific and clinical interest. Forty-nine blastomeres from 5- to 8-cell human embryos have been investigated following an efficient single-cell cDNA amplification protocol to provide a template for high-density microarray analysis. The previously described markers, characteristic of Inner Cell Mass (ICM) (n = 120), stemness (n = 190) and Trophectoderm (TE) (n = 45), were analyzed, and a housekeeping pattern of 46 genes was established. All the human blastomeres from the 5- to 8-cell stage embryo displayed a common gene expression pattern corresponding to ICM markers (e.g., DDX3, FOXD3, LEFTY1, MYC, NANOG, POU5F1), stemness (e.g., POU5F1, DNMT3B, GABRB3, SOX2, ZFP42, TERT), and TE markers (e.g., GATA6, EOMES, CDX2, LHCGR). The EGA profile was also investigated between the 5-6- and 8-cell stage embryos, and compared to the blastocyst stage. Known genes (n = 92) such as depleted maternal transcripts (e.g., CCNA1, CCNB1, DPPA2) and embryo-specific activation (e.g., POU5F1, CDH1, DPPA4), as well as novel genes, were confirmed. In summary, the global single-cell cDNA amplification microarray analysis of the 5- to 8-cell stage human embryos reveals that blastomere fate is not committed to ICM or TE. Finally, new EGA features in human embryogenesis are presented.

Preimplantation genetic screening: an effective testing for infertile and repeated miscarriage patients?

Aneuploidy in pregnancy is known to increase with advanced maternal age (AMA) and associate with repeated implantation failure (RIF), and repeated miscarriage (RM). Preimplantation genetic screening (PGS) has been introduced into clinical practice, screening, and eliminating aneuploidy embryos, which can improve the chance of conceptions for infertility cases with poor prognosis. These patients are a good target group to assess the possible benefit of aneuploidy screening. Although practiced widely throughout the world, there still exist some doubts about the efficacy of this technique. Recent randomized trials were not as desirable as we expected, suggesting that PGS needs to be reconsidered. The aim of this review is to discuss the efficacy of PGS.

Prognostic factors for preimplantation genetic screening in repeated pregnancy loss

The objective of this study was to identify specific subgroups of recurrent pregnancy loss (RPL) patients of unknown aetiology in whom the selection of chromosomally normal embryos for transfer improves reproductive outcome in preimplantation genetic screening (PGS). A total of 428 PGS cycles were included and chromosomes 13, 15, 16, 18, 21, 22, X and Y were evaluated. In RPL patients < or =37 years, a lower incidence of chromosomal abnormalities (P = 0.0004) and miscarriages (P = 0.0283) was observed, and there were significantly higher pregnancy (P < 0.0384) and implantation (P < 0.0434) rates than in patients >37 years. In the former subset, results showed: (i) significantly higher implantation rates (P = 0.0411) in couples that had experienced a previous aneuploid miscarriage; (ii) similar aneuploidy, pregnancy and implantation rates in couples suffering previous miscarriages during fertility treatments and in those with previous spontaneous pregnancies; (iii) no miscarriages after PGS in couples in whom a fluorescence in-situ hybridization assay showed the male partner's sperm to be abnormal; and (iv) lower implantation rates in couples with > or =5 previous miscarriages, associated with a lower percentage of chromosomally abnormal embryos. It is concluded that PGS is to be strongly recommended when RPL is associated with miscarriages during infertility treatments, chromosomopathy in a previous miscarriage, up to five previous miscarriages and a high incidence of chromosomal abnormalities in spermatozoa.

Ovarian function: a theory of relativity

Kol and Homburg recently hypothesized in these pages that the change, rather than currently evaluated absolute hormone values, is important for biological processes. We fully agree, but wish, with this communication, to add to their concept: opposing forces, balancing each other, in order to maintain a system's stability, permeates nature. Loss of such equilibrium, in turn, results in systemic malfunctions with, at times, adverse consequences. Extrapolating to Kol and Homburg's hypothesis, this observation would suggest that not only changes in any given hormone carry biological messages, but that final message derives from hormonal ratios between hormones which oppose each other in physiological effects. In full concurrence to Kol and Homburg, this concept could give rise to better diagnosis and treatment of infertility problems.

Preimplantation genetic screening: "established" and ready for prime time?

Unless attempts to improve pregnancy rates and/or diminish miscarriage rates through preimplantation genetic screening (PGS) are applied to only carefully selected patients, they will fail. Because specific PGS indications have remained undefined, PGS should be considered an experimental procedure.

A high oocyte yield for intracytoplasmic sperm injection treatment is associated with an increased chromosome error rate

OBJECTIVE

To compare the chromosome error rate among oocytes from stimulated ovaries after retrieval of 1-5 oocytes, 6-10 oocytes, and >10 oocytes.

DESIGN

Retrospective cohort study.

SETTING

A university-based human genetic institute in collaboration with a private fertility center.

PATIENT(S)

Nine hundred thirty-three women undergoing intracytoplasmic sperm injection (ICSI) with a poor prognosis.

INTERVENTION(S)

Oocyte collection with ovarian stimulation. Polar body testing of ICSI oocytes for common chromosome errors.

MAIN OUTCOME MEASURE(S)

Chromosome error rate in oocytes, as determined by five-color fluorescence in situ hybridization.

RESULT(S)

In women less than 35 years and women between 35 and 40 years undergoing the first ICSI cycle, oocytes from the high-yield group had an increased likelihood for detectable chromosome errors (50.9% and 54.6%, respectively), compared to the intermediate-yield group (34.9% and 43.8%) and the low-yield group (23.3% and 41.2%). The overall high rate (>or=50%) of chromosomally abnormal oocytes in women more than 40 years appeared to be mainly due to the maternal age effect and increased only slightly with oocyte yield.

CONCLUSION(S)

Oocyte yield may be considered as an indicator of ovarian response to hormone stimulation. In women up to 40 years a high yield of oocytes after superovulation is associated with an increased chromosome error rate.

Predictive value of preimplantation genetic diagnosis for aneuploidy screening in repeated IVF-ET cycles among women with recurrent implantation failure

OBJECTIVE

To determine the predictive value of euploid embryos in women with recurrent implantation failure undergoing repeated IVF-ET cycles with PGD (PGD).

DESIGN

Cohort of IVF-PGD cycles in a tertiary care ART facility. MATERIALS AND METHOD(S): Fifty-five consecutive patients with repeated implantation failure (more than three failed IVF-ET cycles) underwent two or more PGD cycles for aneuploidy testing. Mean maternal age was 37.6+/-5.3 years. Biopsies were performed on day 3. One blastomere was removed from each pre-embryo, fixed and analyzed by multicolor and multi-probe FISH for chromosomes X and Y, 13, 15, 16, 17, 18, 21, and 22.

RESULT(S)

Forty-three of 55 patients (78%) undergoing PGD had at least one euploid embryo for transfer. Of these 31 patients (72%) also had at least one euploid embryo available for transfer with the second cycle. Of the 12 (28%) patients with no euploid embryos available for transfer with the second IVF/PGD cycle, five had a third cycle of PGD and two of these had euploid embryos available for transfer. Seventeen of the 31 patients (55%) who had euploid embryos on the second PGD cycle conceived. The ongoing pregnancy and implantation rates in patients with at least one euploid embryo were 40% and 18%, respectively. Twelve of the 55 patients (22%) had no euploid embryos available for transfer on the first PGD cycle, but on the second PGD cycle, six (50%) of these had euploid embryos for transfer. Only two pregnancies were achieved among this group of women, yielding a pregnancy rate of 17%, but both conceptions resulted in miscarriage. Of the six patients with no euploid embryos available after the second PGD cycle, four patients had a third IVF/PGD cycle, but none had euploid embryos available for transfer. Also, among women with euploid embryos available only in either the first or second PGD cycle, but not both, no ongoing pregnancy was achieved. No woman who had a PGD cycle productive of no euploid embryos had an ongoing pregnancy. Significant differences were found in terms of ongoing pregnancy (40%, P<0.05) and implantation rates (18%, P<0.05) in women with euploid embryos available for transfer with the first and second IVF/PGD cycles, compared to women with no euploid embryos available for transfer with either the first or second cycle. The positive predictive value of the first euploid cycle predicting a second euploid cycle was 72%, 95% CI 0.66-0.78. The negative predictive value of an aneuploid cycle was 50%, 95% CI 0.27-0.72. The sensitivity and specificity of the first PGD cycle predicting the second was 84%, 95% CI 0.77-0.91 and 33%, 95% CI 0.18-0.48, respectively.

CONCLUSION(S)

Even with a history of recurrent implantation failure, the availability of euploid embryos, especially on two, consecutive PGD cycles is associated with high ongoing pregnancy and implantation rates. Conversely, the absence of euploid embryos for transfer predicts poor reproductive outcome, even if subsequent cycles do yield euploid embryos.