Horizons in Endometriosis: Proceedings of the Montreux Reproductive Summit, 14-15 July 2023

Endometriosis is a complex and chronic gynaecological disorder that affects millions of women worldwide, leading to significant morbidity and impacting reproductive health. This condition affects up to 10% of women of reproductive age and is characterised by the presence of endometrial-like tissue outside the uterus, potentially leading to symptoms such as chronic pelvic pain, dysmenorrhoea, dyspareunia, and infertility. The Montreux summit brought a number of experts in this field together to provide a platform for discussion and exchange of ideas. These proceedings summarise the six main topics that were discussed at this summit to shed light on future directions of endometriosis classification, diagnosis, and therapeutical management. The first question addressed the possibility of preventing endometriosis in the future by identifying risk factors, genetic predispositions, and further understanding of the pathophysiology of the condition to develop targeted interventions. The clinical presentation of endometriosis is varied, and the correlation between symptoms severity and disease extent is unclear. While there is currently no universally accepted optimal classification system for endometriosis, several attempts striving towards its optimisation - each with its own advantages and limitations - were discussed. The ideal classification should be able to reconcile disease status based on the various diagnostic tools, and prognosis to guide proper patient tailored management. Regarding diagnosis, we focused on future tools and critically discussed emerging approaches aimed at reducing diagnostic delay. Preserving fertility in endometriosis patients was another debatable aspect of management that was reviewed. Moreover, besides current treatment modalities, potential novel medical therapies that can target underlying mechanisms, provide effective symptom relief, and minimise side effects in endometriotic patients were considered, including hormonal therapies, immunomodulation, and regenerative medicine. Finally, the question of hormonal substitution therapy after radical treatment for endometriosis was debated, weighing the benefits of hormone replacement.

The HERA (Hyper-response Risk Assessment) Delphi consensus for the management of hyper-responders in in vitro fertilization

PURPOSE

To provide agreed-upon guidelines on the management of a hyper-responsive patient undergoing ovarian stimulation (OS) METHODS: A literature search was performed regarding the management of hyper-response to OS for assisted reproductive technology. A scientific committee consisting of 4 experts discussed, amended, and selected the final statements. A priori, it was decided that consensus would be reached when ≥66% of the participants agreed, and ≤3 rounds would be used to obtain this consensus. A total of 28/31 experts responded (selected for global coverage), anonymous to each other.

RESULTS

A total of 26/28 statements reached consensus. The most relevant are summarized here. The target number of oocytes to be collected in a stimulation cycle for IVF in an anticipated hyper-responder is 15-19 (89.3% consensus). For a potential hyper-responder, it is preferable to achieve a hyper-response and freeze all than aim for a fresh transfer (71.4% consensus). GnRH agonists should be avoided for pituitary suppression in anticipated hyper-responders performing IVF (96.4% consensus). The preferred starting dose in the first IVF stimulation cycle of an anticipated hyper-responder of average weight is 150 IU/day (82.1% consensus). ICoasting in order to decrease the risk of OHSS should not be used (89.7% consensus). Metformin should be added before/during ovarian stimulation to anticipated hyper-responders only if the patient has PCOS and is insulin resistant (82.1% consensus). In the case of a hyper-response, a dopaminergic agent should be used only if hCG will be used as a trigger (including dual/double trigger) with or without a fresh transfer (67.9% consensus). After using a GnRH agonist trigger due to a perceived risk of OHSS, luteal phase rescue with hCG and an attempt of a fresh transfer is discouraged regardless of the number of oocytes collected (72.4% consensus). The choice of the FET protocol is not influenced by the fact that the patient is a hyper-responder (82.8% consensus). In the cases of freeze all due to OHSS risk, a FET cycle can be performed in the immediate first menstrual cycle (92.9% consensus).

CONCLUSION

These guidelines for the management of hyper-response can be useful for tailoring patient care and for harmonizing future research.

Failure to detect DNA in blastocoel fluid is associated with a higher live birth rate in both PGT-A and conventional IVF/ICSI cycles

STUDY QUESTION

Is the presence of DNA in the blastocoel fluid (BF) of expanded blastocysts, assessed by whole genome amplification (WGA), associated with the clinical outcome at the first transfer?

SUMMARY ANSWER

At the first transfer, blastocysts with negative BF-WGA have more chance to implant and to develop to term than those with positive BF-WGA results, both in preimplantation genetic testing for aneuploidies (PGT-A) cycles (where only euploid blastocysts resulting from the chromosomal analysis of trophectoderm (TE) biopsies were transferred) and in IVF/ICSI conventional cycles.

WHAT IS KNOWN ALREADY

Retrospective studies conducted in patients undergoing PGT-A have shown that the incidence of negative BF-WGA was significantly higher in TE-euploid blastocysts than in TE-aneuploid blastocysts. In addition, after the transfer of TE-euploid blastocysts, the ongoing clinical pregnancy rate was significantly higher in the group with negative BF-WGA compared with those with positive BF-WGA.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study including 102 consecutive PGT-A patients (Group 1) and 88 consecutive conventional IVF/ICSI patients (Group 2), was conducted between January 2019 and December 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In both groups, BFs were collected from expanded blastocysts of high grade and processed for WGA. DNA amplification was evaluated by agarose gel electrophoresis for the presence (positive BF-WGA) or absence (negative BF-WGA) of a band. Directly after the BF retrieval, blastocysts from Group 1 underwent TE biopsy and vitrification. In Group 2, blastocysts were vitrified immediately after BF collection. In Group 1, only euploid blastocysts were considered for transfer according to the results of TE biopsies. In both groups, the selection of the blastocyst to be transferred was based on BF-WGA results giving priority, if available, to those with negative amplification. The primary outcome investigated was the live birth rate (LBR) at the first transfer. The main variable under investigation was the negative BF-WGA and results were corrected for confounders (maternal and paternal age, number of retrieved oocytes, male factor) by multiple logistic regression analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

In Group 1, 60 patients transferred negative BF-WGA blastocysts and 42 positive BF-WGA blastocysts, and the LBR at the first transfer was 53.3% and 26.2%, respectively (P = 0.0081). After testing for selected confounders in a multiple logistic analysis, the transfer of blastocysts with negative BF-WGA resulted in an odds ratio of (OR) 3.52 (95% CI: 1.48-8.88, P = 0.0057) compared to transfer of positive BF-WGA blastocysts. In Group 2, at the first transfer 30 deliveries resulted from blastocysts with negative BF-WGA (48.4%) and three from the transfer of positive BF-WGA blastocysts in 26 patients (11.5%; P = 0.0014). Multiple logistic analysis indicated that the transfer of blastocysts with negative BF-WGA resulted in an OR 6.89 (95% CI: 1.98-32.95, P = 0.0056) compared to transfer of positive BF-WGA blastocysts. The LBR per transfer and the cumulative LBR per patient showed the same trend.

LIMITATIONS, REASONS FOR CAUTION

The study was performed in a single center.

WIDER IMPLICATIONS OF THE FINDINGS

The data from this study highlight the heterogeneity of blastocysts of similar morphology, even in those classified as euploid by TE analysis. Failure to detect DNA in BFs after WGA is associated with a significantly higher LBR at the first embryo transfer as well as per transfer and per patient. The processing of the BF by WGA is an easy and cost-effective tool that could become a valuable option to offer patients the highest chances of term pregnancy in the shortest time possible.

STUDY FUNDING/COMPETING INTEREST(S)

The study received no funding from external sources. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

O-074 Whole genome amplification (WGA) of blastocoelic fluid (BF) as an additional criterion for the selection of the most viable embryo

Study question

Is the presence or absence of DNA in the blastocoelic fluid detected by whole genomic amplification (WGA) a valid method to prioritize embryos for transfer?

Summary answer

Blastocysts with DNA in the BF have lower ongoing pregnancy rates compared with blastocysts without DNA, both in PGT-A and in conventional IVF cycles

What is known already

The detection of DNA in BFs from expanded blastocysts has been reported in different studies. After amplification, this DNA can be analyzed to provide information on the blastocyst chromosome condition, but the degree to which it is representative of the corresponding embryo ploidy is still controversial. The reason of this divergence could reside in several factors, including the different status of the studied embryos. A recent study comparing euploid and aneuploid blastocysts reported a significantly higher incidence of failed BF-DNA amplification in euploid blastocysts compared with aneuploid blastocysts suggesting an effect of the embryo ploidy condition on BF content

Study design, size, duration

This prospective study included 142 cycles with PGT-A (Group-1; 24-chromosome analysis was performed on trophectoderm (TE) biopsies) and 121 conventional IVF consecutive cycles (Group-2) treated in the last three years. In both groups, the BF was collected from expanded blastocysts before vitrification, and submitted to WGA. Single blastocyst transfers were performed by selecting blastocysts based on BF-WGA results giving priority to those with failed amplification. In Group-1, only TE-euploid blastocysts were transferred

Participants/materials, setting, methods

Patients in Group-1 had a maternal age higher than in Group-2 (36.8±3 vs 34.1±3.5 years). The same protocol of vitrification was used for all patients, and only expanded blastocysts of high grade were included in the study. Amplification after WGA was evaluated by loading an aliquot of the amplified product onto a 1.5% agarose gel. An ongoing pregnancy was defined as a pregnancy regularly ongoing beyond the 16th week of gestation

Main results and the role of chance

In Group-1, a total of 622 blastocysts underwent trophectoderm (TE) biopsy and 261 were euploid. The BF was retrieved from 237 euploid blastocysts and submitted to WGA. Amplification failure resulted in 98 BFs, whereas 139 BF gave a positive amplification. In all, 57 clinical pregnancies resulted, 53 of which were regularly ongoing. 61 transfers were performed with euploid blastocysts with failed BF-WGA, and 81 with positive BF-WGA. When looking at the transfer outcome, the ongoing pregnancy rate was significantly higher for euploid blastocysts with failed BF-WGA (31/61, 50.8%) when compared to those with positive BF-WGA results (22/81, 27.2%, p<0.01). In Group-2, there were 62 clinical pregnancies, 52 of which were ongoing. In relation to the BF-WGA results, the ongoing pregnancy rate showed the same trend of Group-1, and was 20% (52/121) for blastocysts with failed BF-WGA and 59.1% (42/71, p<0.001) for blastocysts with positive BF-WGA

Limitations, reasons for caution

This is a prospective cohort study. The results should be confirmed by a prospectively randomized study

Wider implications of the findings

The presence of DNA in the BF could be indicative of an abnormal embryos that is trying to reach a viable condition. Therefore, failure to detect DNA after BF amplification could represent an additional criterion to select viable embryos for transfer both in PGT-A and in conventional IVF cycles

Trial registration number

Not applicable

P–040 Correlation between DNA fragmentation index and big halo pattern with sperm decondensation index and semen sample parameters

Study question

Does sperm DNA integrity evaluated by DNA fragmentation index (DFI) and big halo pattern correlate with sperm decondensation index (SDI) and semen sample parameters?

Summary answer

DFI correlates with SDI and semen sample parameters in a stronger way than the big halo pattern

What is known already

The sperm chromatin dispersion test evaluates DNA integrity by measuring the susceptibility of sperm DNA containing breaks to denature when treated by an acid solution. Spermatozoa with intact DNA produce big or medium size halos of dispersed DNA loops, whereas small halos or no halos indicate fragmented DNA. The DFI calculates the proportion of spermatozoa with fragmented DNA. Data have been published documenting the negative effect of sperm DFI on embryo viability, suggesting that its evaluation could contribute to the prediction of the male reproductive potential

Study design, size, duration

A prospective study between 2011 to 2019 included 300 patients attending our clinic for fertility treatment. All sperm samples were analyzed according to WHO criteria, and the results from the DNA integrity analysis were related to the semen sample indices

Participants/materials, setting, methods

Of the 300 males included in the study, 118 were normozoospermic, 16 were oligozoospermic (O), 63 were asthenozoospermic (A), 9 were teratozoospermic, 7 were AT, 51 were OA, 5 were OT, and 31 OAT. The DNA integrity was assessed by the Halosperm test, and DNA decondensation by the aniline blue assay. A big halo was defined as a dispersion greater or equal to the length of the minor diameter of the core

Main results and the role of chance

DFI showed negative correlations with progressive motility (r= –0.532, p = 2.816 E–23), total motility (r= –0.598, p = 1.688 E–30) and morphology (r= –0.338, p = 2.954 E–9). Accordingly, when compared with normozoospermic, DFI was significantly higher in A and T samples (29.5 ±12.0 and 36.5±4.8 respectively, p < 0.002) with the highest levels found in samples with combined defects (45.2±12.5 in AT, p < 0.002; 51.3±17.2 in OAT, p < 0.002). DFI also showed a negative correlation with the big halo pattern (r= –0.656, p = 2.934 E–38) and a positive correlation with the SDI (r = 0.429, p = 7.314 E–15). For the big halo, negative correlations were found with progressive motility (r = 0.429, p = 7.314 E–15) and morphology (r = 0.407, p = 4.077 E–13) resulting in a lower incidence in T samples (27.0±9.6, p < 0.002) that was especially relevant in AT (18.3±14.5, p < 0.002), OT (33.0±10.2, p < 0.02) and OAT samples (20.6±15.8, p < 0.002). SDI presented a negative correlation with total motility (r= –0.403, p = 3.849 E–13) and was fond to be increased in A samples (32.4±11.8, p < 0.002) as well as in samples with double defects (38.9±19.2 in AT samples and 38.8±15.9 in OA samples, p < 0.002) and triple defects (42.6±16.8 in OAT, p < 0.002)

Limitations, reasons for caution

The study did not evaluate the lifestyle and reproductive history of the patients

Wider implications of the findings: Although the effects of sperm DNA damage on reproductive outcomes are still unclear, the correlation between sperm DNA fragmentation, semen parameters and reproductive potential is emerging. DFI, big halo and SDI could contribute to the diagnosis of male infertility especially in categories of patients with poor prognosis of pregnancy.

Trial registration number

Not applicable

P–575 Patients with recurrent implantation failures (RIF): chromosome abnormalities in the resulting embryos

Study question

Do RIF patients have the preimplantation genetic testing for aneuploidy (PGT-A) overcome their infertility condition?

Summary answer

PGT-A positively impact on implantation rate in RIF patients

What is known already

The most common definition of RIF is failure to achieve a pregnancy after three consecutive transfers of good quality embryos. This term possibly represents a heterogeneous category of infertile couples as the causes of repeated failures can be diverse. Especially intriguing is the case of patients with an age lower than 39 years for which the oocyte quality is expected not to be compromised by the well known age effect on female fertility. The chromosome analysis of the resulting embryos has been proposed as a valid method to improve implantation in the great majority of RIF patients

Study design, size, duration

This retrospective study included 49 patients with at least three previous consecutive implantation failures, which underwent PGT-A from January 2016 to April 2020. Both partners had a normal karyotype. Only patients with a female age below 39 years were included, who presented with a normal uterine cavity. Couples with a severe male factor were excluded. Single frozen blastocysts were transferred according to chromosomal results

Participants/materials, setting, methods

Maternal age was 35.5 ± 3.1 years. All blastocysts were vitrified after trophectoderm biopsy. Whole genome amplification and array comparative genomic hybridization were performed on biopsies. Only euploid embryos were transferred. The primary outcome was the live-birth delivery rate after the first transfer

Main results and the role of chance

Before starting a PGT-A cycle, these patients underwent 213 embryo transfers with 251 embryos replaced. A total of 264 blastocysts were analyzed, 140 of which were aneuploid (53%). Monosomy or trisomy was reported in 67 of the diagnosed samples (67/140, 48%) whereas the remaining 73 carried complex aneuploidies (73/140, 52%). The remaining 124 blastocysts (47%) were diagnosed as euploid. All patients performed an embryo transfer resulting in 28 clinical pregnancies (57%). There were 5 spontaneous abortions and the live-birth delivery rate per patient was 47%

Limitations, reasons for caution

This study suffers from the weakness related to retrospectivity. In addition, as euploid embryos are still cryopreserved, the delivery rate could change at completion of the cycles

Wider implications of the findings: A RIF condition can be attributed, at least in a good proportion of cases, to the generation of high percentages of aneuploid embryos. In this case, the transfer of euploid blastocysts has high chances to classify this category of RIF patients has having an embryonic cause of infertilit.

Trial registration number

Not applicable

Permanence of de novo segmental aneuploidy in sequential embryo biopsies

STUDY QUESTION

Is de novo segmental aneuploidy (SA) a biological event or an artifact that is erroneously interpreted as partial chromosome imbalance?

SUMMARY ANSWER

The detection of de novo SA in sequential biopsies of preimplantation embryos supports the biological nature of SA.

WHAT IS KNOWN ALREADY

Although some SAs are detected in oocytes and in blastocysts, the highest incidence is observed in cleavage-stage embryos. Based on these findings, we can postulate that the majority of cells affected by SAs are eliminated by apoptosis or that affected embryos mainly undergo developmental arrest.

STUDY DESIGN, SIZE, DURATION

This retrospective study includes 342 preimplantation genetic testing for aneuploidy (PGT-A) cycles performed between January 2014 and December 2018. Chromosome analysis was performed on 331 oocytes, 886 cleavage-stage embryos and 570 blastocysts (n = 1787). From 268 expanded blastocysts, the blastocoelic fluid (BF) was also analyzed (resulting in 2025 samples in total). In cases of SAs involving loss or gain in excess of 15 Mb, embryos were not considered for transfer and sequential biopsies were performed at following stages. This resulted in 66 sets where the initial diagnosis of SAs (4 made in polar bodies, 25 in blastomeres and 37 in trophectoderm (TE) cells) was followed up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2082 samples (2025 + 27 whole embryos) were processed by whole genome amplification followed by array comparative genomic hybridization.

MAIN RESULTS AND THE ROLE OF CHANCE

The incidence of SAs was 6.3% in oocytes, increased to 16.6% in cleavage-stage embryos (P < 0.001) and decreased to 11.2% in blastocysts (P < 0.025 versus oocytes; P < 0.01 versus cleavage-stage embryos). The highest incidence of SAs was found in BFs (26.1%, P < 0.001). The analysis of 66 sets of sequential biopsies revealed that the initial finding was confirmed in all following samples from 39 sets (59.1% full concordance). In 12 additional sets, SAs were detected in some samples while in others the interested chromosome had full aneuploidy (18.2%). In three more sets, there was a partial concordance with the initial diagnosis in some samples, but in all TE samples the interested chromosome was clearly euploid (4.5%). In the remaining 12 sets, the initial SA was not confirmed at any stage and the corresponding chromosomes were euploid (18.2% no concordance). The pattern of concordance was not affected by the number of SAs in the original biopsy (single, double or complex) or by the absence or presence of concomitant aneuploidies for full chromosomes.

LIMITATIONS, REASONS FOR CAUTION

Chromosome analyses were performed on biopsies that might not be representative of the true constitution of the embryo itself due to the occurrence of mosaicism.

WIDER IMPLICATIONS OF THE FINDINGS

The permanence of SAs throughout the following stages of embryo development in more than half of the analyzed sets suggests for this dataset a very early origin of this type of chromosome imbalance, either at meiosis or at the first mitotic divisions. Since SAs remained in full concordance with the initial diagnosis until the blastocyst stage, a corrective mechanism seems not to be in place. In the remaining cases, it is likely that, as for full chromosome aneuploidy, mosaicism derived from mitotic errors could have occurred. In following cell divisions, euploid cell lines could prevail preserving the embryo chances of implantation. Due to the scarcity of data available, the transfer of embryos with SAs should be strictly followed up to establish possible clinical consequences related to this condition.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained. There are no conflicts of interest.

Recent developments in genetics and medically assisted reproduction: from research to clinical applications

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Recent developments in genetics and medically-assisted reproduction: from research to clinical applications†‡

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively-parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Trends over 15 years in ART in Europe: an analysis of 6 million cycles

Study question

Was the European IVF Monitoring (EIM) Consortium, established in 1999 by ESHRE, able to monitor the trend over time of ART in Europe?

Summary answer

The initial aims of the EIM programme (to collect and publish regional European data on census and trends on ART utilization, effectiveness, safety and quality) have been achieved.

What is already known

ART data in Europe have been collected and reported annually in Human Reproduction.

Study design, size, duration

A retrospective data analysis and summary of the first 15 years of ART activity in Europe (1997–2011) was carried out, using the key figures from the annual ESHRE reports and focusing on how the practice of ART has evolved over the years.

Participants/materials, setting, method

A total of 5 919 320 ART cycles are reported, including IVF, ICSI, frozen embryo relacment and egg donation, resulting in the birth of more than 1 million infants. A total of 1 548 967 IUIs are also reported, including husband/partner’s semen and donor semen cycles. The most relevant and complete data are analysed and discussed.

Main results and the role of chance

With some fluctuations, the number of countries and clinics reporting to EIM increases significantly from 1997 to 2011. A constant increase was also registered in the number of annual cycles reported. Since 2005, the estimation of the EIM coverage on the total European activity was >80%. In countries with 100% of coverage, the mean availability of ART increased from 765 cycles per million inhabitants in 1997 to 1269 cycles per million inhabitants in 2011, and the proportion of ART infants of the total number of infants born in the country increased from 1.3% to 2.4%. The proportion of women aged > 39 years undergoing IVF and ICSI cycles gradually increased. For 12 consecutive years, the proportion of ICSI versus IVF cycles showed a marked increase before reaching a plateau from 2008. The proportion of transfers with three or more embryos decreased constantly and the proportion of SETs increased over the time period. The triplets deliveries were reduced from 3.7% in 1997 to less than 1% since 2005 (0.6% in 2011). The effectiveness (evaluated as clinical pregnancy rate per aspiration and per embryo transfer) increased until 2007, then the figure remained stable. The cumulative percentage of documented pregnancy losses was 17%. No differences have been noted in terms of outcomes in the IUI cycles.

Limitations, reasons for caution

The data presented are accumulated from countries with different collection systems, regulations, insurance coverage and different practices. Each year a number of countries have been unable to provide some of the data.

Wider implications of the finding(s)

The first summary of 15 years of the EIM reports offers interesting data on census and trends on ART utilization, safety and quality in Europe. The primary aim of the ESHRE effort in supporting European data collection has been reached. Owing to its importance inside and outside the professional community, European data collection and publication on ART have to be supported and implemented.

Study funding/competing interest(s)

None.

The comprehensiveness of the ESHRE/ESGE classification of female genital tract congenital anomalies: a systematic review of cases not classified by the AFS system

STUDY QUESTION

How comprehensive is the recently published European Society of Human Reproduction and Embryology (ESHRE)/European Society for Gynaecological Endoscopy (ESGE) classification system of female genital anomalies?

SUMMARY ANSWER

The ESHRE/ESGE classification provides a comprehensive description and categorization of almost all of the currently known anomalies that could not be classified properly with the American Fertility Society (AFS) system.

WHAT IS KNOWN ALREADY

Until now, the more accepted classification system, namely that of the AFS, is associated with serious limitations in effective categorization of female genital anomalies. Many cases published in the literature could not be properly classified using the AFS system, yet a clear and accurate classification is a prerequisite for treatment.

STUDY DESIGN, SIZE AND DURATION

The CONUTA (CONgenital UTerine Anomalies) ESHRE/ESGE group conducted a systematic review of the literature to examine if those types of anomalies that could not be properly classified with the AFS system could be effectively classified with the use of the new ESHRE/ESGE system. An electronic literature search through Medline, Embase and Cochrane library was carried out from January 1988 to January 2014. Three participants independently screened, selected articles of potential interest and finally extracted data from all the included studies. Any disagreement was discussed and resolved after consultation with a fourth reviewer and the results were assessed independently and approved by all members of the CONUTA group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Among the 143 articles assessed in detail, 120 were finally selected reporting 140 cases that could not properly fit into a specific class of the AFS system. Those 140 cases were clustered in 39 different types of anomalies.

MAIN RESULTS AND THE ROLE OF CHANCE

The congenital anomaly involved a single organ in 12 (30.8%) out of the 39 types of anomalies, while multiple organs and/or segments of Müllerian ducts (complex anomaly) were involved in 27 (69.2%) types. Uterus was the organ most frequently involved (30/39: 76.9%), followed by cervix (26/39: 66.7%) and vagina (23/39: 59%). In all 39 types, the ESHRE/ESGE classification system provided a comprehensive description of each single or complex anomaly. A precise categorization was reached in 38 out of 39 types studied. Only one case of a bizarre uterine anomaly, with no clear embryological defect, could not be categorized and thus was placed in Class 6 (un-classified) of the ESHRE/ESGE system.

LIMITATIONS, REASONS FOR CAUTION

The review of the literature was thorough but we cannot rule out the possibility that other defects exist which will also require testing in the new ESHRE/ESGE system. These anomalies, however, must be rare.

WIDER IMPLICATIONS OF THE FINDINGS

The comprehensiveness of the ESHRE/ESGE classification adds objective scientific validity to its use. This may, therefore, promote its further dissemination and acceptance, which will have a positive outcome in clinical care and research.

STUDY FUNDING/COMPETING INTERESTS

None.

A Bayesian network model for predicting pregnancy after in vitro fertilization

We present a Bayesian network model for predicting the outcome of in vitro fertilization (IVF). The problem is characterized by a particular missingness process; we propose a simple but effective averaging approach which improves parameter estimates compared to the traditional MAP estimation. We present results with generated data and the analysis of a real data set. Moreover, we assess by means of a simulation study the effectiveness of the model in supporting the selection of the embryos to be transferred.

Best practices of ASRM and ESHRE: a journey through reproductive medicine

BACKGROUND

The American Society for Reproductive Medicine (ASRM) and the European Society of Human Reproduction and Embryology (ESHRE) are the two largest societies in the world whose members comprise the major experts and professionals working in the field of reproductive medicine and embryology. These societies have never before had a joint scientific meeting.

METHODS

A 3-day meeting was planned and took place in March of 2012. The goal was to present and debate key topics, as well as modes of practice in reproductive medicine and to discuss recent developments in the field.

RESULTS

Presentations by members of ASRM and ESHRE were of three types: 'state of the art' lectures, 'back-to-back' presentations of two points of view and debates.

CONCLUSIONS

For the first time, ASRM and ESHRE held a joint meeting where a special emphasis was given to presentations on the hottest topics in the field. Although different opinions and approaches sometimes exist on the two sides of the Atlantic, an appreciation and acceptance of these differences was evident, and there was more commonality than divergence of opinion.

ESHRE consensus on the definition of 'poor response' to ovarian stimulation for in vitro fertilization: the Bologna criteria

The definition presented here represents the first realistic attempt by the scientific community to standardize the definition of poor ovarian response (POR) in a simple and reproducible manner. POR to ovarian stimulation usually indicates a reduction in follicular response, resulting in a reduced number of retrieved oocytes. It has been recognized that, in order to define the poor response in IVF, at least two of the following three features must be present: (i) advanced maternal age or any other risk factor for POR; (ii) a previous POR; and (iii) an abnormal ovarian reserve test (ORT). Two episodes of POR after maximal stimulation are sufficient to define a patient as poor responder in the absence of advanced maternal age or abnormal ORT. By definition, the term POR refers to the ovarian response, and therefore, one stimulated cycle is considered essential for the diagnosis of POR. However, patients of advanced age with an abnormal ORT may be classified as poor responders since both advanced age and an abnormal ORT may indicate reduced ovarian reserve and act as a surrogate of ovarian stimulation cycle outcome. In this case, the patients should be more properly defined as 'expected poor responder'. If this definition of POR is uniformly adapted as the 'minimal' criteria needed to select patients for future clinical trials, more homogeneous populations will be tested for any new protocols. Finally, by reducing bias caused by spurious POR definitions, it will be possible to compare results and to draw reliable conclusions.

Predicting aneuploidy in human oocytes: key factors which affect the meiotic process

BACKGROUND

To estimate the incidence of aneuploidy in relation to patients' characteristics, the type of hormonal stimulation and their response to induction of multiple follicular growth, 4163 first polar bodies (PB1s) were analyzed.

METHODS

Five hundred and forty four infertile couples underwent 706 assisted conception cycles (640 with poor prognosis indications and 66 controls) in which chromosomal analysis of PB1 for the chromosomes 13, 15, 16, 18, 21 and 22 was performed. Results were evaluated in a multivariate analysis.

RESULTS

The proportion of normal oocytes was directly correlated (P < 0.01) with (i) the number of mature oocytes and (ii) the establishment of a clinical pregnancy; and inversely correlated (P < 0.01) with (i) female age, (ii) causes of female infertility (endometriosis, abortions, ovulatory factor), (iii) poor prognosis indications (female age, number of previous cycles, multiple poor prognosis indications), (iv) number of FSH units per oocyte and (v) number of FSH units per metaphase II oocyte. There was a weak significance of frequency (P < 0.05) between type of abnormality (originated by chromatid predivision, chromosome non-disjunction or combined mechanisms in the same oocyte) and groups of the studied variables, rather than to a specific abnormality or a specific chromosome.

CONCLUSIONS

The type of infertility had a significant effect on errors derived from the first meiotic division, whose incidence was significantly higher in the presence of endometriosis or of an ovulatory factor, and in women that experienced repeated abortions. Each aneuploidy event was found to be dependent not on a specific variable, but on groups of variables. In addition, the tendency of chromosomal abnormalities to occur simultaneously implies that the deriving aneuploidies can be of any type.