Embryos with high implantation potential after intracytoplasmic sperm injection can be recognized by a simple, non-invasive examination of pronuclear morphology

Variation of Female Pronucleus Reveals Oocyte or Embryo Chromosomal Copy Number Variations

The characteristics of the human pronuclei (PNs), which exist 16-22 h after fertilization, appear to serve as good indicators to evaluate the quality of human oocyte and embryo, and may reflect the status of female and male chromosome composition. Here, a quantitative PN measurement method that is generated by applying expert experience combined with deep learning from large annotated datasets is reported. After mathematic reconstruction of PNs, significant differences are obtained in chromosome-normal rate and chromosomal small errors such as copy number variants by comparing the size of the reconstructive female PN. After integrating the whole procedure of PN dynamics and adjusting for errors that occur during PN identification, the results are robust. Notably, all positive prediction results are obtained from the female propositus population. Thus, the size of female PNs may mirror the internal quality of the chromosomal integrity of the oocyte. Embryos that develop from zygotes with larger female PNs may have a reduced risk of copy number variations.

Twinning in ART: Single embryo transfer policy

It is more than thirty years that perinatologists and healthcare personnel aim to reduce the morbidity associated with multiple pregnancy. In many cases, these complications stem from pregnancies achieved through artificial reproductive technologies (ART). Although dramatic measures have been taken to control those risks by increasing the proportion of single embryo transfers, the multiple pregnancy rate still remains relatively high among patient conceived through ART, carrying risks to both mothers and newborns, and is coupled with the related economic burden associated with prematurity. The aim of this review is to provide the current evidence regarding single embryo transfer to assist decision-makers and to promote patient knowledge toward an elective policy to reduce the risk of twinning. Single embryo transfer may aid in the further reduction of multiple pregnancy and, in most cases, will maintain patient autonomy and right of choice.

Oocyte quality and embryo selection strategies: a review for the embryologists, by the embryologists

With the advance of assisted reproduction techniques, and the trend towards blastocyst culture and single embryo transfer, gamete and embryo assessment have gained greater importance in ART treatment. Embryo quality depends mainly on gamete quality and culture conditions. Oocyte maturity identification is necessary in order to plan fertilization timing. Mature oocytes at the metaphase II stage show a higher fertilization rate compared to immature oocytes. Morphology assessment is a critical yet challenging task that may serve as a good prognostic tool for future development and implantation potential if done effectively. Various grading systems have been suggested to assess embryos at pronuclear, cleavage, and blastocyst stages. By identifying the embryo with the highest implantation potential, it is possible to reduce the number of embryos transferred without compromising the chances of a successful pregnancy. Apart from the conventional morphology assessment, there are several invasive or non-invasive methods for embryo selection such as preimplantation genetic testing, morphokinetics, proteomics, metabolomics, oxygen consumption, and measurement of oxidative stress in culture medium. Morphokinetics is a method based on time-lapse technology and continuous monitoring of embryos. In this review, we aim to describe and compare the most effective and widely used methods for gamete and embryo assessment as well as embryo selection.

Use of platelet-rich plasma in the treatment of infertility in poor responders in assisted human reproduction procedures

Couple infertility is a pathology with an absolute number of cases growing markedly over the last decade in connection mainly with the increased age of couples wishing to conceive. Platelet-rich plasma (PRP) is an alternative treatment used for several years for experimental purposes. Yet, this method is not yet defined as a standard therapeutic option in the infertility protocol for poor responders in assisted human reproduction procedures. Thus, the present study is a retrospective study conducted between February 2019 and February 2020 to evaluate the effect of ovarian PRP injection in patients with a poor ovarian response (POR) to ovarian stimulation. Women (n=20; age 31-44 years) diagnosed with POR based on the European Society of Human Reproduction and Embryology criteria underwent ovarian injection with autologous PRP injection. Markers of ovarian reserve before, during the following two menstrual cycles, and at six months after treatment were followed as well as stimulation and fertilisation parameters before and post-treatment. PRP treatment resulted in increased antral follicle count and serum anti-Mullerian hormone, while levels of serum follicle-stimulating hormone and luteinising hormone were decreased. These changes were more pronounced during the 2nd menstrual cycle following treatment. By six months following the injection, their values return to pre-treatment levels and any small differences were not considered statistically significant. The average dose of gonadotropin used and duration remained statistically unchanged, but a significant increase in estradiol achieved by the day of the human chorionic gonadotropin trigger day was achieved. The cancellation rate decreased following PRP treatment while the number of collected oocytes, number of oocytes in metaphase II rose. The number of embryos (of A and B quality) resulting also increased but fell short of the significance level set (α=0.073). Following the PRP injection, two singleton pregnancies were achieved, resulting in live births at term without complications during pregnancy. Another pregnancy was achieved spontaneously 45 months following the PRP and a failed assisted human reproduction procedure. Although the group included a small number of women, the results indicate the potential benefits of an ovarian autologous PRP injection in women with POR. Positive results appear to be short-term for 2-6 months after the procedure.

Pronuclear score improves prediction of embryo implantation success in ICSI cycles

BACKGROUND

In assisted reproduction technology embryo competence is routinely evaluated on morphological criteria but efficacy remains relatively low. Additional information could be obtained by evaluating pronuclear (PN) morphology. Up to now controversial results have been reported about the prognostic value of PN score. One of the main limitations of literature data is the use of different PN classification methods. In this regard, in 2011 the ESHRE and Alpha Scientists in Reproductive Medicine defined three PN categories to standardize zygote assessment. In this study we evaluated whether the consensus ESHRE-Alpha system for the pronuclear scoring could be an useful additional criterion to improve prediction of embryo implantation potential.

METHODS

This is a retrospective, longitudinal, observational, cohort study. We included 3004 zygotes from 555 women who underwent ICSI treatment at our Center between January 2014 and June 2019. The PN were categorized as score 1: symmetrical, 2: non-symmetrical, 3: abnormal. A subset of 110 zygotes did not cleaved. On day 2-3 1163 embryos were transferred, 232 arrested, and 9 were cryopreserved. Among the 1490 embryos cultured up to day 5-7, 516 became blastocysts: 123 were transferred on day 5 and 393 were cryopreserved. Comparisons of age, cleavage and blastocyst rate, quality of embryos, implantation success among PN score groups were evaluated by chi-square test or Kruskal-Wallis test as appropriate. Potential predictors of embryo implantation were first tested in univariable analysis using generalized estimating equations taking into account correlation between embryos originated from the same patient. Then, variables potentially associated with implantation success (P<0.05) were included in a multivariable analysis for calculating the adjusted odds ratio (OR) and 95% confidence interval (CI).

RESULTS

There was no significant difference in patients'age, cleavage and blastulation rates, and embryo morphology among the three PNscore groups. The PN score 1-embryos had a greater implantation success respect to score 2-3-ones (OR 1.83; 95% CI 1.34-2.50, P=0.0001). Consistently, the pronuclear score remained predictive of implantation in top quality embryos (OR 1.68; 95%CI 1.17-2.42, P= 0.005).

CONCLUSIONS

The consensus pronuclear score may be routinely included among criteria for embryo evaluation to increase patients' chance of becoming pregnant.

Necessity is the mother of invention and the evolutionary force driving the success of in vitro fertilization

During the last few decades, millions of healthy children have been born with the aid of in vitro fertilization (IVF). This success belies the fact that IVF treatment is comprised of a complex series of interventions starting with a customized control ovarian stimulation protocol. This is followed by the induction of oocyte maturation, the retrieval of mature oocytes and in vitro fertilization, which often involves the microinjection of a single sperm into the oocyte. After fertilization, the resulting embryos are cultured for up to 7 days. The best embryos are transferred into the uterus where the embryo implants and hopefully develops into a healthy child. However, frequently the best embryos are biopsied and frozen. The biopsied cells are analyzed to identify those embryos without chromosomal abnormalities. These embryos are eventually thawed and transferred with pregnancy rates as good if not better than embryos that are not biopsied and transferred in a fresh cycle. Thus, IVF treatment requires the coordinated efforts of physicians, nurses, molecular biologists and embryologists to conduct each of these multifaceted phases in a seamless and flawless manner. Even though complex, IVF treatment may seem routine today, but it was not always the case. In this review the evolution of human IVF is presented as a series of innovations that resolved a technical hurdle in one component of IVF while creating challenges that eventually lead to the next major advancement. This step-by-step evolution in the treatment of human infertility is recounted in this review.

The Effect of GH Administration on Oocyte and Zygote Quality in Young Women With Repeated Implantation Failure After IVF

Growth hormone (GH) has been shown to improve implantation and live birth rates in women of >40 years of age treated by in vitro fertilization (IVF). This effect was initially attributed to a GH effect on oocyte quality, but later studies showed that GH can also improve uterine receptivity for embryo implantation. As to younger women with previous failures of embryo implantation after IVF, data reported in the literature are ambiguous. This retrospective study focused on this latter category of women, comparing the numbers and morphological appearance of oocytes recovered from women with two previous IVF failures, aged between 30 and 39 years and treated with GH, with a comparable group of women without GH treatment. These results were complemented with the analysis of morphological markers of zygote and embryo quality and IVF clinical outcomes in both groups. The oocytes, zygotes and embryos from women treated with GH showed better morphological scores, and their uterine transfer resulted in more implantations, pregnancies and live births, as compared with the untreated group. It is concluded that the improvement of IVF outcomes in women with previous repeated IVF failures by exogenous GH administration is, at least partly, related to an increase in oocyte developmental potential. The statistically evident improvement of oocyte and embryo quality is the main finding of this study. Its weakness is its retrospective nature.

Live Birth Rate After Transfer of Fresh or Frozen Poor Quality Day-3 Embryos Only

Background: Embryo quality is an important predictor of successful outcome in in vitro fertilization (IVF). However, current knowledge on the live birth rate after transfer of poor quality embryos is limited. This study investigated the live birth rate after transfer of only poor quality day-3 embryos in women undergoing IVF.

Methods: This retrospective study included 153 couples who underwent IVF at IVFMD, My Duc Hospital, Ho Chi Minh City, Vietnam between June 2014 and January 2017 and had only poor quality day-3 embryos available for fresh (n [Formula: see text] 102) or frozen (n [Formula: see text] 51) transfer. The control group included patients who had transfer of one good embryo (n [Formula: see text] 64). Embryos were rated using the Istanbul criteria.

Results: In the poor quality embryo group, the mean number of oocytes retrieved and number of embryos were 7.5 ± 4.4 and 1.8 ± 0.9, respectively. Mean number of embryos transferred was 1.6 ± 0.5 in the fresh transfer group and 2.0 ± 0.2 in the freeze-only group. Live births did occur after transfer of poor quality embryos, but the implantation, clinical pregnancy and live birth rates were significantly lower than after fresh or frozen transfer of a single good quality embryo (9.5 vs. 26.6%, p < 0.001; 13.7 vs. 26.6%, p < 0.001; and 7.2 vs. 18.8%, p [Formula: see text] 0.02, respectively).

Conclusions: Live birth was achieved after transfer of only poor quality embryos in women undergoing IVF. This suggests that transfer of poor quality embryos could be an option when higher grade embryos are not available, after the chances of live birth have been discussed with the patient.

Acquired Sperm DNA Modifications: Causes, Consequences, and Potential Solutions

DNA of human spermatozoa can be subject to various kinds of modifications acquired throughout life. Put simply, two basic types of acquired sperm DNA modifications can be distinguished: genetic and epigenetic. Genetic modifications cause alterations of the DNA sequence and mainly result from the formation of breakpoints leading to sperm DNA fragmentation. Epigenetic modifications include a vast spectrum of events that influence the expression of different genes without altering their DNA sequence. Both the genetic and the epigenetic modifications of sperm DNA can negatively influence embryonic development, cause miscarriages, and be the origin of different health problems for the offspring. As to sperm DNA fragmentation, reliable diagnostic methods are currently available. On the other hand, the detection of potentially harmful epigenetic modifications in spermatozoa is a much more complicated issue. Different treatment options can be chosen to solve problems associated with sperm DNA fragmentation. Some are relatively simple and noninvasive, based on oral treatments with antioxidants and other agents, depending on the underlying cause. In other cases, the recourse to different micromanipulation-assisted in vitro fertilisation techniques is necessary to select spermatozoa with minimal DNA damage to be injected into oocytes. The treatment of cases with epigenetic DNA modifications is still under investigation. Preliminary data suggest that some of the techniques used in cases of extensive DNA fragmentation can also be of help in those of epigenetic modifications; however, further progress will depend on the availability of more reliable diagnostic methods with which it will be possible to evaluate the effects of different therapeutic interventions.

The association between quality of supernumerary embryos in a cohort and implantation potential of the transferred blastocyst

PURPOSE

Despite studies focused on the association between embryo morphology and implantation potential, it is unknown how the collective quality of the supernumerary embryos in a cohort is associated with the implantation rate (IR) of the transferred embryo. This study tested the hypothesis that a relationship exists between the quality of the supernumerary cohort and IR.

METHODS

A retrospective cohort study of first fresh autologous IVF cycles from 05/2012 to 09/2016, with ≥ 3 blastocysts, resulting in a single blastocyst transfer (n = 819) was performed. Cohorts were grouped in two ways: by mean priority score (PS; 1 being best) of supernumerary embryos and by percent supernumerary embryos with low implantation potential. The relationship between cohort quality and IR was assessed using logistic regression.

RESULTS

As mean cohort PS increased, IR of the transferred embryo decreased (test for linear trend, p = 0.05). When ≥ 75% of the supernumerary cohort was predicted to have low implantation potential, IR of the transferred embryo was significantly lower compared to when < 75% of the cohort was predicted to have low implantation potential (OR 0.71; 95% CI (0.53-0.94)). All associations were attenuated when adjusting for PS of the transferred embryo.

CONCLUSIONS

Our findings suggest that quality of supernumerary embryos is associated with IR of the transferred embryo, among patients with ≥ 3 blastocysts available on day 5. As cohort quality declines and the proportion of low implantation potential embryos increases, the IR of the transferred embryo declines. These associations are attenuated when controlling for quality of the transferred embryo, suggesting that the relationship between embryo cohort quality and implantation is not independent of the transferred embryo quality.

An overview of the available methods for morphological scoring of pre-implantation embryos in in vitro fertilization

Assessment of embryo quality in order to choose the embryos that most likely result in pregnancy is the critical goal in assisted reproductive technologies (ART). The current trend in human in vitro fertilization/embryo transfer (IVF/ET) protocols is to decrease the rate of multiple pregnancies after multiple embryo transfer with maintaining the pregnancy rate at admissible levels (according to laboratory standards). Assessment of morphological feathers as a reliable non-invasive method that provides valuable information in prediction of IVF/intra cytoplasmic sperm injection (ICSI) outcome has been frequently proposed in recent years. This article describes the current status of morphological embryo evaluation at different pre-implantation stages.

Using the Society for Assisted Reproductive Technology Clinic Outcome System morphological measures to predict live birth after assisted reproductive technology

OBJECTIVE

To model morphological assessments of embryo quality that are predictive of live birth.

DESIGN

Longitudinal cohort using cycles reported in the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS) between 2007 and 2011.

SETTING

Clinic-based data.

PATIENT(S)

Fresh autologous assisted reproductive technology (ART) cycles with ETs on day 3 or day 5 and morphological assessments reported (25,409 cycles with one embryo transferred and 96,093 cycles with two embryos transferred). Live-birth rates were modeled by morphological assessments using backward-stepping logistic regression for cycle 1 and over five cycles, separately for day 3 and day 5 transfers and number of embryos transferred (1 or 2). Additional models for each day of transfer also included the number of oocytes retrieved and the number of embryos cryopreserved.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live births.

RESULT(S)

Morphological assessments of grade, stage, fragmentation, and symmetry were significant for the day 3 models; grade, stage, and trophectoderm were significant in the day 5 model; inner-cell mass was significant in the models when two embryos were transferred. Number of oocytes retrieved and number of embryos cryopreserved were significant for both day 3 and day 5 models.

CONCLUSION(S)

These findings confirm the significant association between embryo quality parameters reported to SART CORS and live-birth rate after ART.

Embryo culture and selection: morphological criteria

In this chapter, we have outlined the various morphological criteria for selection of the best embryo at each important milestone encountered in the progress from the oocyte to the blastocyst. As Gerris et al. stated, a combination of one, two, or even three selection points should lead to a more accurate selection of the best embryo, as no one criterion is better than the other. An embryo that fails to meet the entire set of selection criteria must be avoided as culture cannot correct an impaired embryo.

Investigation of the association between the outcomes of sperm chromatin condensation and decondensation tests, and assisted reproduction techniques

The main purpose of this prospective study is to examine possible influences of abnormalities of sperm nuclear condensation and chromatin decondensation with sodium dodecyl sulphate (SDS)-EDTA on outcomes of intrauterine insemination (IUI) or intracytoplasmic sperm injection (ICSI) cycles. Semen samples from 122 IUI and 236 ICSI cycles were evaluated. Before semen preparation for IUI or ICSI, basic semen analysis was performed and a small portion from each sample was spared for fixation. The condensation of sperm nuclear chromatin was evaluated with acidic aniline blue, followed by sperm chromatin decondensation by SDS-EDTA and evaluation under light microscope. Ongoing pregnancy rate was 24% and 26.2% in the IUI and ICSI groups respectively. The chromatin condensation rate was significantly higher in the ongoing pregnancy-positive group compared to the negative group, both in IUI (P = 0.042) and ICSI groups (P = 0.027), and it was positively correlated with ongoing pregnancy rate in both IUI and ICSI groups (P = 0.015, r = 0.214 and P = 0.014, r = 0.312 respectively). Chromatin decondensation rates were not significantly different in neither of the groups. These results indicate that IUI and ICSI outcome is influenced by the rate of spermatozoa with abnormal chromatin condensation. Sperm chromatin condensation with aniline blue is useful for selecting assisted reproduction techniques (ART) patients.

Embryo quality but not pronuclear score is associated with clinical pregnancy following IVF

PURPOSE

The association between pronuclear (PN) scoring of embryos from assisted reproductive technology (ART) and clinical pregnancy remains controversial. We hypothesized that embryos with PNs scored on the day of fertilization check offer better embryo selection on day 3 and higher CPR compared to non-PN scored embryos.

METHODS

Patients (19-46 years) undergoing IVF/ICSI cycles at Montefiore's Institute for Reproductive Medicine and Health between January 2006 and December 2009 were included in our study. We analyzed fresh day 3 cycles only with autologous oocytes and partner's fresh sperm (n = 344). A total of 1,899 embryos were included. We compared CPR from non-PN scored embryos (Group 1, n = 835) with PN scored embryos (Group 2, n = 1,064). Composite scores by patient were developed based on embryo disposition. We also assessed traditional embryo grading derived from cell number, fragmentation and cell symmetry. Data analysis included chi square and t test to determine if PN scoring was associated with improved CPR, and to compare the additional variables.

RESULTS

CPR between Group 1 and Group 2 were not different (p = 0.91). CPR was significantly associated with female age, number of mature oocytes retrieved, number of day 3 embryos and grade of embryos transferred on day 3 (p < 0.05).

CONCLUSION

PN scoring was not associated with improved CPR in day 3 embryo transfers. Mean grade of transferred embryos continues to be a well-established, independent predictor of CPR. We conclude that further refinement of embryo grading by PN scoring is not beneficial.

Pronuclear morphology evaluation for fresh in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles: a systematic review

The current systematic review was aimed to assess the effectiveness of the zygote morphology evaluation in fresh in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles. All available studies reporting on zygote morphology and clinical and/or biological outcomes were analyzed. Forty studies were included in the final analysis. Fourteen different zygote scoring systems were employed. Zygote morphology correlated significantly with embryo quality and cleavage, blastocyst stage, embryonic chromosome status, in a high proportion of the studies which assessed the specific outcome [15/25 (60%), 15/20 (75%), 7/8 (87.5%), 6/6 (100%), respectively]. On the other hand, only a reduced proportion of papers showed a statistically significant relationship between implantation, pregnancy and delivery/live-birth rates and zygote morphology score [12/23 (52.2%), 12/25 (48%), 1/4 (25%), respectively]. In conclusion, our findings demonstrate the lack of conclusive data on the clinical efficacy of the zygote morphology evaluation in fresh IVF/ICSI cycles, even if biological results showing a good relationship with embryo viability suggest a role in cycles in which the transfer/freezing is performed at day 1.

Quality evaluation of IVM embryo and imprinting genes of IVM babies

Purpose

Oxygen consumption rates of human embryos derived from in vitro matured (IVM) oocytes and controlled ovarian hyperstimulation (COH) were compared with scanning electrochemical microscopy (SECM) non-invasively in order to answer why embryos from IVM oocytes have lower developmental potential. We also analyzed the epigenetic disorders for IVM babies born in our clinic.

Methods

The oxygen consumption rate was calculated with the SECM system for different maturation stages of human oocytes, IVM and COH embryos. Blood from umbilical cords of IVM babies was collected to examine the imprinting genes.

Results

There were no significant differences in oxygen consumption of embryos at each cleavage stage between IVM and COH (range 0.26–0.56 × 10¹⁴/mol S⁻¹). There also was no abnormality found in expression of imprinting genes in IVM babies.

Conclusions

There are no differences in terms of oxygen consumption between embryos derived from IVM and COH. There was no imprinting gene disorder founded from IVM babies.

The combination of pronuclear and blastocyst morphology: a strong prognostic tool for implantation potential

PURPOSE

To (i) investigate a possible association between different features of pronuclear (PN) morphology and different features of blastocyst morphology, (ii) evaluate the combination of PN and blastocyst morphologies as a predictive factor for ICSI outcomes and (iii) identify possible contributing factors to poor PN morphology.

METHODS

This study included 908 normally fertilised zygotes reaching full blastocyst stage, obtained from 350 patients undergoing ICSI cycles, in which the implantations rates were 0 % or 100 %. The influence of PN morphology on blastocyst morphology and on the rates of pregnancy and miscarriage was investigated. Embryos were graded and split into three groups, taking into consideration both the PN and the blastocyst status. The pregnancy rate was compared among these groups.

RESULTS

Inner cell mass (ICM) alterations were correlated with the number of nucleolar precursor bodies (NPB), while trophectoderm alterations were correlated with the size of the pronuclei and the distribution of the NPB. The distribution of the NPB had an impact on the chances of pregnancy. A significant difference was observed among the groups regarding the pregnancy rate. The maternal age, number of aspirated follicles and number of retrieved oocytes influenced the incidence of PN defects.

CONCLUSIONS

These findings suggest that a lower oocyte yield may lead to higher-quality PN zygotes. In addition, different PN features may influence further embryo development, especially the quality of the blastocyst. Moreover, the association between PN and blastocyst morphology may be used as a prognostic tool for implantation.

Oocyte morphology on day 0 correlates with aneuploidy as detected by polar body biopsy and FISH

PURPOSE

For better selection of oocytes and embryos, preimplantation genetic screening (PGS) was introduced. As from the beginning of IVF, morphology was used as selection criteria; we investigated the combination of both. If there was a correlation between phenotype and genotype, invasive PGS might be replaced.

METHOD

Therefore, 104 cycles with PGS were done by biopsy of the first polar body and FISH with five chromosomes. Morphology of the oocyte was recorded digitally and noted for 12 categories in 4-13 values; evaluation of the chromosomes was noted for five chromosomes in five values. Morphology and genetics were correlated to each other.

RESULT

Correlations between morphology and genetics for day 0 were found: oocytes with an irregular or dark zona are less probable to have a normal chromosome 13 (80 vs. 53 %, p = 0.001). A medium amount of detritus in the perivitelline space makes it more probable to have a normal chromosome 18 (94 vs. 78 %, p = 0.001). A halo in the cytoplasm makes it less probable to be euploid for chromosome 22 (56 vs. 75 %, p = 0.018). For day 1, pattern "1, 2, 3 and fine" in the pronuclei makes it more probable to be euploid for chromosome 22 (78 vs. 63 %, p = 0.002).

CONCLUSION

There are correlations between the oocyte genome and its morphology also on day 0. These correlations are not sufficient to replace PGS.

Number of supernumerary vitrified blastocysts is positively correlated with implantation and live birth in single-blastocyst embryo transfers

OBJECTIVE

To estimate whether live birth in single-blastocyst transfers is correlated with the number of sibling supernumerary vitrified blastocysts (embryos not transferred) generated from that same cycle.

DESIGN

Retrospective cohort study.

SETTING

A large academic assisted reproduction clinic.

PATIENT(S)

All single-blastocyst transfers in 2010 graded as "good" embryos by Society for Assisted Reproductive Technologies (SART) criteria.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Implantation and live birth.

RESULT(S)

Of the 655 single-blastocyst transfers that met inclusion criteria, implantation occurred in 65% and live birth in 54% of cycles. In chi-square analysis, patients with supernumerary vitrified blastocysts had a statistically higher implantation rate (65% versus 50%) and live-birth rate (56% versus 41%) when compared with patients without supernumerary blastocysts. Univariate logistic regression demonstrated an increase in implantation (OR 1.09; 95% CI, 1.03-1.15) and live birth (OR 1.06; 95% CI, 1.02-1.09) with increasing number of supernumerary blastocysts. Multivariate logistic regression analysis demonstrated that patient age and the number of supernumerary blastocysts were statistically significantly associated with implantation and live birth.

CONCLUSION(S)

The number of supernumerary vitrified blastocysts correlated positively with the odds of implantation and live birth in good quality single-blastocyst transfers. Patients with supernumerary blastocysts are good candidates for single-embryo transfer.

Is cryopreservation of embryos a legitimate surrogate marker of embryo quality in studies of assisted reproductive technology conducted using national databases?

OBJECTIVE

To investigate whether cryopreservation of supernumerary embryos is a good surrogate for embryo quality.

DESIGN

Retrospective study of 6,859 assisted reproductive technology (ART) cycles from women aged <35 years with two fresh day 3 embryos transferred.

SETTING

National Society for Assisted Reproductive Technology Clinic Outcome Reporting System data from 2006-2008.

PATIENT(S)

Women undergoing ART.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Embryo quality (good, fair, or poor), cell number, and live births were compared for cycles with and without cryopreservation, using χ(2) to evaluate statistical significance. The association of freezing with embryo quality was examined using multiple logistic regression after adjusting for confounders (patient age, oocyte yield, intracytoplasmic sperm injection [ICSI], assisted hatching, male factor infertility).

RESULT(S)

Cycles with cryopreservation were more likely to have two embryos of good quality transferred (81.3% vs. 48.5%) and had more 8-cell embryos transferred (76.0% vs. 50.1%). Relative to cycles with two good embryos (good-good), the adjusted odds ratios (OR) for cryopreservation were: good-fair (OR = 0.301, 95% confidence interval [CI] = 0.257-0.354), fair-fair (OR = 0.308, 95% CI = 0.258-0.367), and any poor (OR = 0.058, 95% CI = 0.040-0.083). The live birth rate was 52.4% for cycles with freezing and 40.6% for cycles without.

CONCLUSION(S)

Embryo quality and cell number were both associated with embryo cryopreservation. However, although cryopreservation was a strong marker for good quality, not having cryopreservation did not reliably indicate poor quality, as almost half of those cycles had two good quality embryos.

The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting

BACKGROUND

Many variations in oocyte and embryo grading make inter-laboratory comparisons extremely difficult. This paper reports the proceedings of an international consensus meeting on oocyte and embryo morphology assessment.

METHODS

Background presentations about current practice were given.

RESULTS

The expert panel developed a set of consensus points to define the minimum criteria for oocyte and embryo morphology assessment.

CONCLUSIONS

It is expected that the definition of common terminology and standardization of laboratory practice related to embryo morphology assessment will result in more effective comparisons of treatment outcomes. This document is intended to be referenced as a global consensus to allow standardized reporting of the minimum data set required for the accurate description of embryo development.

Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting

This paper reports the proceedings of an international consensus meeting on oocyte and embryo morphology assessment. Following background presentations about current practice, the expert panel developed a set of consensus points to define the minimum criteria for oocyte and embryo morphology assessment. It is expected that the definition of common terminology and standardization of laboratory practice related to embryo morphology assessment will result in more effective comparisons of treatment outcomes. This document is intended to be referenced as a global consensus to allow standardized reporting of the minimum dataset required for the accurate description of embryo development. This paper reports the proceedings and outcomes of an international consensus meeting on human oocyte and embryo morphology assessment. An expert panel developed a series of consensus points to define the minimum criteria for such assessments. The definition of common terminology, and standardization of laboratory practices related to these morphological assessments, will permit more effective comparisons of treatment outcomes around the world. This report is intended to be referenced as a global consensus to allow standardized reporting of the minimum descriptive criteria required for routine clinical evaluations of human embryo development in vitro.

Severe teratozoospermia and its influence on pronuclear morphology, embryonic cleavage and compaction

BACKGROUND

Fertilization, cell division and embryo development depend on genomic contributions from male and female gametes. We hypothesize that teratozoospermic sperm influences early embryo development and embryo compaction.

METHODS

We conducted a retrospective analysis of embryos derived from intracytoplasmic sperm injection (ICSI) cycles. Two hundred thirty-five consecutive ICSI cycles were included in the study; all treatment was provided at the Cleveland Clinic Fertility Center. Patient cycles were divided by sperm morphology based on Kruger's strict criteria: Group A, embryos where teratozoospermic sperm (0-2% normal) were used for ICSI and Group B, embryos where dysmorphic sperm (5-13% normal) were used for ICSI. All cycles analyzed were of patients doing day 3 embryo transfers. Outcome measures assessed included pronuclear (PN) pattern, syngamy, early cleavage, cell number, rate of compaction and blastulation of embryos left in culture and not transferred on day 3.

RESULTS

A total of 1762 embryos were analyzed. PN patterns were similar in Group A and Group B embryos. No differences were noted in syngamy, cleavage, cell number or blastulation rate. Studying the development of embryos in culture after day 3 transfer revealed a difference in the timeline for compaction. By day 4, 25% of Group A embryos had compacted compared to 36% in Group B (P = 0.0007). There was no difference found between Group A and Group B embryos in regards to blastulation.

CONCLUSIONS

We did not find an association between sperm morphology and clinical outcomes. The impact of teratozoospermia may be masked in ICSI cycles where fertilization, implantation rate and clinical pregnancy rate are the primary outcome measures. However, by examining the timeline of development, we were better able to discern a potential paternal effect at critical transition points from fertilization through activation.

National collection of embryo morphology data into Society for Assisted Reproductive Technology Clinic Outcomes Reporting System: associations among day 3 cell number, fragmentation and blastomere asymmetry, and live birth rate

OBJECTIVE

To evaluate the validity of collecting day 3 embryo morphology variables into the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS).

DESIGN

Retrospective.

SETTING

National database-SART CORS.

PATIENT(S)

Fresh autologous assisted reproductive technology (ART) cycles from 2006-2007 in which embryos were transferred singly (n=1,020) or in pairs (n=6,508) and embryo morphology was collected.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Relationship between live birth, maternal age, and morphology of transferred day 3 embryos as defined by cell number, fragmentation, and blastomere symmetry. Logistic multiple regressions and receiver operating characteristic curve analyses were applied to determine specificity and sensitivity for correctly classifying embryos as either failures or successes.

RESULT(S)

Live birth rate was positively associated with increasing cell number up to eight cells (<6 cells: 2.9%; 6 cells: 9.6%; 7 cells: 15.5%; 8 cells: 24.3%; and >8 cells: 16.2%), but was negatively associated with maternal age, increasing fragmentation, and asymmetry scores. An area under the receiver operating curve of 0.753 (95% confidence interval 0.740-0.766) was derived, with a sensitivity of 45.0%, a specificity of 83.2%, and 76.4% of embryos being correctly classified with a cutoff probability of 0.3.

CONCLUSION(S)

This analysis provides support for the validity of collecting morphology fields for day 3 embryos into SART CORS. Standardization of morphology collections will assist in controlling for embryo quality in future database analyses.

Serum antimüllerian hormone concentrations on day 3 of the in vitro fertilization stimulation cycle are predictive of the fertilization, implantation, and pregnancy in polycystic ovary syndrome patients undergoing assisted reproduction

OBJECTIVE

To determine the possible relationship between serum antimüllerian hormone (AMH) concentrations on day 3 and controlled ovarian stimulation and reproductive outcomes in women with polycystic ovary syndrome.

DESIGN

Prospective, clinical trial.

SETTING

University hospital.

PATIENT(S)

Sixty women with PCOS.

INTERVENTION(S)

Serum concentrations of AMH measured on cycle day 3.

MAIN OUTCOME MEASURE(S)

Clinic pregnancy rate (CPR), implantation rate (IR), and fertilization rate (FR).

RESULT(S)

The CPR, IR, and FR were markedly different among the day-3 serum AMH groups (low, moderate, and high AMH groups). The CPR were 33.3, 46.1, and 60.0, respectively, in the low, moderate, and high serum AMH groups on day 3. The embryo IR were 18.6, 26.7, and 36.3, respectively. The FR were 54, 68, and 79, respectively. An AMH level≥3.01 ng/mL was shown to predict FR with a sensitivity of 86.4% and specificity of 75%. An AMH level≥3.2 ng/mL was shown to predict IR and CPR with sensitivity and specificity of 72.1% and 72.7%, and 75.6% and 77.3%, respectively.

CONCLUSION(S)

On day 3 of the in vitro fertilization stimulation cycle, serum concentrations of AMH can be used as a marker for ovarian response as well as reproductive outcome in assisted reproductive cycles of PCOS patients.

Follicular-fluid anti-Mullerian hormone concentrations are predictive of assisted reproduction outcome in PCOS patients

Serum anti-Mullerian hormone (AMH) concentrations constitute a sensitive marker for ovarian ageing. In addition, concentrations of AMH in the follicular fluid constitute a useful marker of embryo implantation in assisted reproduction cycles. The present study measured serum and follicular-fluid AMH concentrations on the day of oocyte retrieval. These data showed that clinical pregnancy rates (25.0, 34.1 and 42.1%, respectively, P < 0.001), embryo implantation rates (24.3, 35.0 and 44.4%, respectively, P < 0.001) and fertilization rates (59.2, 70.9 and 79.5%, respectively, P < 0.001) were markedly different among the low, moderate and high follicular-fluid AMH groups but not among the different serum AMH concentration groups. Follicular-fluid AMH concentrations were negatively correlated with follicular-fluid oestradiol concentrations. The results of this study suggest that follicular-fluid AMH concentration on the day of oocyte retrieval would appear to better reflect the reproductive outcome in PCOS patients undergoing assisted reproduction.

Pronuclear zygote score following intracytoplasmic injection of hyaluronan-bound spermatozoa: a prospective randomized study

The aim of this study was to determine whether the early stages of embryo development, as assessed by the zygote score (Z-score), could be influenced by the injection of spermatozoa that had been preselected on the basis of their binding to hyaluronic acid (HA). A total of 407 sibling metaphase II oocytes, belonging to 44 different patients, were injected in a prospective randomized way, with either hyaluronic acid bound (HA(+) ) or non-bound (HA(-)) spermatozoa. The fertilization rate (75-70%), the percentage of the different Z-scores (Z 1: 22-24%, Z 2: 22-22.5%, Z 3: 44- 45%, Z 4: 12-8.5%), the mean score of the transferred embryos (3.76 +/- 1.29, 3.78 +/- 1.1) and the number of embryos at the 4-cell stage 45 h after injection (77-76%) were not different between the two groups. The ongoing pregnancy rate in this study (>20 weeks of gestation) was 36.4% per replacement, the implantation rate 28% and the twin pregnancy rate 44% (7/16). Although binding to HA did not apparently influence the Z-score, this agent continues to be used for the immobilization of spermatozoa prior to injection, on the basis that it is a natural product that can easily be metabolized by the oocyte via normal biological mechanisms.

Blastocyst culture: myth or magic?

The development of sequential serum-free culture medium has led to a reported increase in implantation rate after transfer of embryos on days 5-6 (approximately 40%) compared with those achieved after transfer on days 2-3 (approximately 20%). However, there are numerous uncertainties surrounding extended culture that need to be considered. This article examines some of the problems and questions considered in relation to the following areas: the developmental capacity of the embryo in vitro; the uterine environment after embryo transfer; the clinical indications surrounding blastocyst transfer including a reduction in multiple pregnancy rate and relevance in preimplantation genetic diagnosis (PGD); and the introduction of blastocyst culture into the embryology laboratory.

The influence of early cleavage on embryo developmental potential and IVF/ICSI outcome

PURPOSE

To observe whether early cleavage can be a predictor of embryo developmental potential, pregnancy and implantation rates.

METHODS

A total of 9,544 embryos in 1,095 in vitro fertilization or intracytoplasmic sperm injection cycles were observed with regard to the appearance of early cleavage at 25-29 h post-insemination.

RESULTS

A significantly higher proportion of excellent quality embryos were observed in the early cleavage group compared to the late cleavage group (52.5 versus 28.9%, P < 0.01). In the early cleavage group there was also a higher rate of pregnancy per transfer compared with the late cleavage group (38.7 versus 26.3%, P < 0.01). In addition, we found that transfer of only one early cleavage embryo resulted in a high pregnancy rate (38.5%) and a low multiple pregnancy rate (18.0%).

CONCLUSION

Early cleavage is a strong indicator of embryo quality, and may be used as an additional criterion in the selection of embryos for transfer to increase pregnancy rate and reduce multiple pregnancy rate.

Impact of GnRH analogues on oocyte/embryo quality and embryo development in in vitro fertilization/intracytoplasmic sperm injection cycles: a case control study

BACKGROUND

Despite the clinical outcomes of ovarian stimulation with either GnRH-agonist or GnRH-antagonist analogues for in vitro fertilization (IVF) being well analysed, the effect of analogues on oocyte/embryo quality and embryo development is still not known in detail. The aim of this case-control study was to compare the efficacy of a multiple-dose GnRH antagonist protocol with that of the GnRH agonist long protocol with a view to oocyte and embryo quality, embryo development and IVF treatment outcome.

METHODS

Between October 2001 and December 2008, 100 patients were stimulated with human menopausal gonadotrophin (HMG) and GnRH antagonist in their first treatment cycle for IVF or intracytoplasmic sperm injection (ICSI). One hundred combined GnRH agonist + HMG (long protocol) cycles were matched to the GnRH antagonist + HMG cycles by age, BMI, baseline FSH levels and by cause of infertility. We determined the number and quality of retrieved oocytes, the rate of early-cleavage embryos, the morphology and development of embryos, as well as clinical pregnancy rates. Statistical analysis was performed using Wilcoxon's matched pairs rank sum test and McNemar's chi-square test. P < 0.05 was considered statistically significant.

RESULTS

The rate of cytoplasmic abnormalities in retrieved oocytes was significantly higher with the use of GnRH antagonist than in GnRH agonist cycles (62.1% vs. 49.9%; P < 0.01). We observed lower rate of zygotes showing normal pronuclear morphology (49.3% vs. 58.0%; P < 0.01), and higher cell-number of preembryos on day 2 after fertilization (4.28 vs. 4.03; P < 0.01) with the use of GnRH antagonist analogues. The rate of mature oocytes, rate of presence of multinucleated blastomers, amount of fragmentation in embryos and rate of early-cleaved embryos was similar in the two groups. Clinical pregnancy rate per embryo transfer was lower in the antagonist group than in the agonist group (30.8% vs. 40.4%) although this difference did not reach statistical significance (P = 0.17).

CONCLUSION

Antagonist seemed to influence favourably some parameters of early embryo development dynamics, while other morphological parameters seemed not to be altered according to GnRH analogue used for ovarian stimulation in IVF cycles.

Evaluation of day one embryo quality and IVF outcome--a comparison of two scoring systems

BACKGROUND

The aim of our retrospective study was to compare the clinical usefulness of two non-invasive embryo scoring systems based either on a simplified pronuclear morphology of the zygote or on early cleavage rate, as well as their combination, for the selection of embryos with the best implantation potential in embryo transfer (ET).

METHODS

Over a period of five years, the quality of 2708 embryos from 364 IVF cycles in women under the age of 39 years was assessed using these scoring systems in a university assisted reproduction centre. ET was always performed on day 3 of cultivation. The outcome of ETs of 702 embryos scored in the respective systems or their combination was retrospectively analyzed in terms of biochemical (bPR) and clinical pregnancy rates (cPR) and implantation rate (IR). Mann-Whitney U test and t-test for differences between relative values were used, p < 0.05 was considered statistically significant.

RESULTS

There was no difference in outcome parameters in 109 cycles where only Pattern "0" zygotes, according to our simplified pronuclear morphology classification, were transferred and 140 cycles where only "other" pattern zygotes were transferred, regardless of their cleavage rate. On the contrary, significantly greater cPR and IR (p = 0.003 and p = 0.006, respectively) were achieved in 120 cycles where only early cleavage (EC) embryos were transferred compared with 152 cycles where only non early cleavage (NEC) embryos were transferred regardless of their pronuclear morphology. The best outcome in terms of cPR (56%) and IR (43%) was found in 50 cycles when Pattern "0" and EC embryos only were used for transfer.

CONCLUSION

The results indicate that early cleavage is a better independent marker of implantation potential than zygote morphology. The best outcome can be achieved if both embryo scoring systems are used jointly and the embryo is classified as EC and Pattern "0".

Comparison of embryological and clinical outcome in GnRH antagonist vs. GnRH agonist protocols for in vitro fertilization in PCOS non-obese patients. A prospective randomized study

PURPOSE

Embryological and clinical efficacy of gonadotropin-releasing hormone (GnRH) antagonist and agonist stimulation protocols in non-obese women with polycystic ovarian syndrome (PCOS) were compared.

METHODS

A prospective randomized study.

SETTING

Medical University Hospital.

PATIENTS

70 infertile PCOS patients; 33 in GnRH antagonist and 37 in GnRH agonist group.

RESULTS

Similar mature metaphase II oocyte rate (76% vs. 76%) was observed in both protocols. Optimal pronuclear morphology zygotes dominated in both groups (64% vs. 66%). Transferred embryo quality did not differ in both protocols. No significant differences between both protocols were found in delivery rate (p = 0.481), pregnancy rate (p = 0.810), multiple pregnancy rate (p = 0.501), miscarriage rate (p = 0.154), fertilization rate (p = 0.388) and implantation rate (p = 1.000). Duration of stimulation and total follicle-stimulating hormone (FSH) dose were significantly lower in GnRH antagonist protocol (p = 0.0005).

CONCLUSIONS

GnRH antagonist and agonist protocols in non-obese PCOS patients yield similar embryological and clinical outcomes. Shorter duration of treatment and lower FSH requirement in GnRH antagonist group may be financially beneficial and therefore attractive for patients.

First polar body and nucleolar precursor body morphology is related to the ovarian reserve of infertile women

This study was undertaken in order to gain insight into the morphology of the first polar body (PB1) and the two pronuclei (2PN) in ICSI patients, specifically the nucleolar precursor bodies (NPB). Whether early abnormalities in these structures are related to the ovarian reserve of infertile women was also studied. Eighty consecutive infertile women were prospectively investigated throughout their first ICSI cycles. Basal ovarian reserve studies were performed in all women. Cycles were evaluated with respect to PB1 and 2PN morphology of the transferred embryos. Cycles that had at least one transferred embryo with normal PB1 and 2PN morphology had significantly better basal ovarian reserve parameters compared with cycles in which all transferred embryos had abnormal PB1 and 2PN morphology. Moreover, the normal morphology group performed significantly better throughout the ovarian stimulation, compared with the abnormal morphology group. Furthermore, the clinical implantation and pregnancy rates were significantly higher in the normal compared with the abnormal morphology group, corresponding to 20.7% versus 10.6% and 42.4% versus 18.2%, respectively. The study concluded that the morphology of the PB1 in metaphase II oocytes as well as that of the NPB within the 2PN zygotes seems to be related to the ovarian reserve in infertile women.

Significance of metaphase II human oocyte morphology on ICSI outcome

OBJECTIVE

To evaluate the influence of specific oocyte morphologic features (morphotypes) on intracytoplasmic sperm injection (ICSI) outcome. The identification of oocyte quality markers is particularly important when a low number of oocytes can be used for IVF.

DESIGN

Retrospective analysis.

SETTING

Medical center.

PATIENT(S)

Five hundred sixteen consecutive ICSI cycles. Only couples affected by severe male factor infertility were excluded.

INTERVENTION(S)

A total of 1,191 metaphase II (MII) oocytes (1-3 per patient) were randomly selected from the cohort of oocytes obtained from each patient and evaluated for morphologic appearance.

MAIN OUTCOME MEASURE(S)

Fertilization, pronuclear morphology, embryo quality, pregnancy rate.

RESULT(S)

There was a presence of vacuoles, abnormal I polar body, and large perivitelline space related to a lower fertilization rate. Pronuclear morphology was effected by the presence of a large perivitelline space, diffused cytoplasmic granularity, and/or centrally located granular area. The latter characteristic also negatively related to day 2 embryo quality. According to the odds ratios obtained for each oocyte morphotype to reach at least one outcome, an MII oocyte morphologic score (MOMS) was calculated. A significant relationship was found between MOMS and female age, female basal FSH, and clinical outcome.

CONCLUSION(S)

Morphologic evaluation before ICSI helps to identify MII oocytes with higher developmental potential.

An oocyte score for use in assisted reproduction

PURPOSE

In this work, we describe a system for the morphological scoring of human oocytes prior to fertilisation and use this system to test whether oocyte morphology is an indicator of fertilisation, embryo development and implantation potential.

METHODS

The study is a prospective trial of the use of oocyte morphological scores in 822 patients undergoing their first cycle of ICSI. Analyses of oocytes were performed prior to ICSI procedures and the scores compared with fertilisation rates, embryo quality and clinical results.

RESULTS

'Top quality' oocytes had a significantly higher level of fertilisation (96%) as compared to low scoring oocytes (25.6%). Where top quality oocytes formed top quality embryos, we noted a clinical success rate of 63.4%.

CONCLUSIONS

Clinical success rates were increased in cases where top quality oocytes formed top quality embryos after ICSI. The analysis of oocyte morphology may represent a positive selection feature during ICSI.