P-541 Prevalence of rare autosomal aneuploidies in pregnancies following assisted reproduction

Study question

Is the prevalence of rare autosomal aneuploidies (RAA) at non-invasive prenatal testing (NIPT) higher in ART pregnancies compared to the general population?

Summary answer

At NIPT there is no higher prevalence of rare autosomal aneuploidies in ART pregnancies compared to the general population.

What is known already

Most IVF embryos contain mixtures of euploid and aneuploid cells. Despite the high prevalence of chromosomal mosaicism in embryos, its clinical implications are poorly understood. Chromosomal mosaicism doesn't seem to be preserved at later stages of prenatal and postnatal development, supported by the birth of children with normal karyotype following mosaic embryo transfer. Recently prospective non-selection PGT-A trials showed equivalent live-birth rates and miscarriage rates across euploid, low-grade mosaic and medium-grade mosaic embryos. However, close monitoring of mosaic embryo transfer may also be warranted due to the potential risk of true fetal mosaicism.

Study design, size, duration

Monocentric retrospective study. Power calculation is based on a prevalence of 0.23% of RAA at moment of NIPT in the general population. Sample sizes were calculated for detecting that the prevalence of RAAs in the ART cohort is higher compared to the overall population. For a power of 80% a sample size of 780 patients is necessary, to allow to conclude that the prevalence of RAAs is not higher than 1% in ART pregnancies.

Participants/materials, setting, methods

This trial was conducted at a tertiary care fertility center. We included all patients who had an IVF/ICSI treatment, without PGT-A, resulting in a pregnancy and had their NIPT done at the genetics department of our hospital between 01/07/2017 and the present. The data were compared to the Belgian national NIPT dataset, which included approximately 154K NIPT results from the general population. These are unique data due to the full reimbursement of NIPT.

Main results and the role of chance

Considering the high prevalence of (mosaic) aneuploidy in preimplantation embryos, we aimed to understand whether the use of assisted reproduction might imply a higher relative risk of RAAs in ART cohort. For our primary outcome comparative analysis revealed that the prevalence of RAA was 0.25% (2/804) in the ART group which was not significantly higher compared to 0.23% (350/153.575) in the general Belgian population, p = 0.89 (Chi square test). In addition, de novo segmental aberrations were also detected in two ART pregnancies (0.25%, 2/804), which is also comparable to the general population group (0,07%, 109/153.575, p = 0.06). Upon invasive follow up, none of RAAs or segmental aneuploidies were confirmed in the foetus, indicating confined placental mosaicism. Hence, our study allows to conclude that the prevalence of RAA at 12 weeks of gestation is not higher than 1% in the ART group and does not differ significantly compared to the general population.

Limitations, reasons for caution

With our data we have a sample size that allows us to conclude that the prevalence of RAA is not higher than 1% in the ART-group, which is highly clinically relevant. To conclude that the prevalence is equal to the general population (0.23%), a larger sample size would be needed.

Wider implications of the findings

Our observation that in ART pregnancies after IVF/ICSI without PGT-A the aneuploid embryos or aneuploid cells from mosaic embryos have disappeared already as early as 12 weeks of gestation development, supports the idea that transfer of putative mosaic embryos is not associated with a higher risk of adverse prenatal outcome.

Trial registration number

s66257

Estimation of the Endometriosis Fertility Index prior to operative laparoscopy

STUDY QUESTION

Can the Endometriosis Fertility Index (EFI) be estimated accurately before surgery?

SUMMARY ANSWER

The EFI can be estimated accurately based on mere clinical/ultrasound information, with some improvement after adding data from diagnostic laparoscopy.

WHAT IS KNOWN ALREADY

The EFI is a validated clinical instrument predicting the probability of pregnancy after endometriosis surgery without the use of ART. Being an end-of-surgery-score, it implies the decision for operative laparoscopy to be made in advance-hence, its role in the pre-surgical decision-making process remains to be established.

STUDY DESIGN, SIZE, DURATION

Single-cohort prospective observational study in 82 patients undergoing complete endometriosis excision (between June and December 2016). Two methods were used to estimate the final EFI: type A based on non-surgical clinical/ultrasound findings only, and type B based on the combination of non-surgical clinical/ultrasound findings and diagnostic laparoscopy data. To calculate EFI type A, an algorithm was created to translate non-surgical clinical/imaging information into rASRM (revised American Society of Reproductive Medicine)-and EFI points. EFI type A and type B estimates were assessed for their clinical and numerical agreement with the final EFI score. Agreement was defined as clinical if EFI scores were within the same range (0-4, 5-6, 7-10), and numerical if their difference was ≤1.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All 82 patients underwent complete laparoscopic CO2-laser excision of any rASRM stage of endometriosis in the Leuven University Fertility Centre (LUFC) of University Hospitals Leuven, a tertiary referral centre for both endometriosis and infertility. An anonymized clinical research file was created. For each patient, three different data sets were created, in order to allow the estimation of the (surgical part) EFI and of the rASRM scores, defined as follows: 'Estimated type A' contained only non-surgical clinical/imaging data, 'Estimated type B' included type A information plus the information of the diagnostic laparoscopy and 'Final EFI' included information of type A, type B and all intra-operative information required to calculate the final EFI. To calculate EFI type A without surgical information, a set of rules was used to translate pre-surgical clinical/imaging information into (rASRM and EFI points). Scoring was done by one person (C.T.), with a time interval of 4 weeks between sessions for each EFI type. Next to the EFI, also rASRM score and stage were calculated.

MAIN RESULTS AND THE ROLE OF CHANCE

Agreement rate between estimated EFI type A and final EFI was high for both the clinical (0.915; 95% CI 0.832-0.965) and numerical definition (0.878; 95% CI 0.787-0.940). Agreement rates between estimated EFI type B and final EFI were even higher (clinical (0.988; 95% CI 0.934-1.000), numerical (0.963; 95% CI 0.897-0.992)).

LIMITATIONS, REASONS FOR CAUTION

Type A estimation is dependent on high-level gynaecological ultrasound expertise, which may not be available in all clinics. A small number of patients had no prior clinical, ultrasound (hard markers) or surgical confirmation of the diagnosis of endometriosis. When applying the estimated EFI type A in clinical practice, a priori assumptions of the presence or absence of endometriosis will need to be made in adjunct to the estimation of the estimated type A EFI when counselling patients on the potential benefit of an (at least diagnostic) laparoscopy. The level of agreement for type A or B should also be taken into account when counselling patients on the type of efforts undertaken to attempt to diagnose or rule out endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

As this study reports, the EFI can be estimated accurately based on clinical/ultrasound data only without the need for any surgical data. This means that the EFI could be used as an instrument to guide joint physician-patient decision-making between surgery, ART or other fertility management options for the individualized treatment of women with endometriosis-related infertility.

STUDY FUNDING/COMPETING INTEREST(S)

During this study period, C.T. was supported by FWO (Research Fund Flanders, Grant number 1700816N) and UZ Leuven KOF (University Hospitals Leuven, Klinisch Onderzoeksfonds).The LUFC received unrestricted research grants from Ferring Pharmaceuticals and Merck SA. Gedeon Richter and MSD sponsored travel to and attendance at scientific meetings. C.M. received consultancy fees from Lumenis (paid to KU Leuven, no private revenue). T.D. has been vice-president and head of global medical affairs infertility for the multinational pharmaceutical company Merck (Darmstadt, Germany) since 1 October 2015. He continues his academic appointment on a part-time basis as Professor of Reproductive Medicine at the University of Leuven (KU Leuven). T.D. has been vice-president and head of global medical affairs infertility for the multinational pharmaceutical company Merck (Darmstadt, Germany) since October 2015. He is also a Guest Professor in Reproductive Medicine and Biology at the Department of Development and Regeneration, Group Biomedical Sciences, KU Leuven (University of Leuven), Belgium, and an Adjunct Professor at the Department of Obstetrics and Gynecology in the University of Yale, New Haven, USA. This work was initiated before he joined Merck KGaA in October 2015, and completed during the subsequent years.

TRIAL REGISTRATION NUMBER

study registration number at UZ Leuven Clinical Trial Centre: S59221.

Plasma miRNAs as biomarkers for endometriosis

STUDY QUESTION

Can plasma miRNAs be used for the non-invasive diagnosis of endometriosis in infertile women?

SUMMARY ANSWER

miRNA-based diagnostic models for endometriosis failed the test of independent validation.

WHAT IS KNOWN ALREADY

Circulating miRNAs have been described to be differentially expressed in patients with endometriosis compared with women without endometriosis, suggesting that they could be used for the non-invasive diagnosis of endometriosis. However, these studies have shown limited consistency or conflicting results, and no miRNA-based diagnostic test has been validated in an independent patient cohort.

STUDY DESIGN, SIZE, DURATION

We performed genome-wide miRNA expression profiling by small RNA sequencing to identify a set of plasma miRNAs with discriminative potential between patients with and without endometriosis. Expression of this set of miRNAs was confirmed by RT-qPCR. Diagnostic models were built using multivariate logistic regression with stepwise feature selection. In a final step, the models were tested for validation in an independent patient cohort.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Plasma of all patients was available in the biobank of the Leuven Endometriosis Centre of Excellence. Biomarker discovery and model development were performed in a discovery cohort of 120 patients (controls = 38, endometriosis = 82), and models were tested for validation in an independent cohort of 90 patients (controls = 30, endometriosis = 60). RNA was extracted with the miRNeasy Plasma Kit. Genome-wide miRNA expression analysis was done by small RNA sequencing using the NEBNext small RNA library prep kit and the NextSeq 500 System. cDNA synthesis and qPCR were performed using the Qiagen miScript technology.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified a set of 42 miRNAs with discriminative power between patients with and without endometriosis based on genome-wide miRNA expression profiling. Expression of 41 miRNAs was confirmed by RT-qPCR, and 3 diagnostic models were built. Only the model for minimal-mild endometriosis (Model 2: hsa-miR-125b-5p, hsa-miR-28-5p and hsa-miR-29a-3p) had diagnostic power above chance performance in the independent validation (AUC = 60%) with an acceptable sensitivity (78%) but poor specificity (37%).

LIMITATIONS, REASONS FOR CAUTION

The diagnostic models were built and tested for validation in two patient cohorts from a single tertiary endometriosis centre. Further validation tests in large cohorts with patients from multiple endometriosis centres are needed.

WIDER IMPLICATION OF THE FINDINGS

Our study supports a possible biological link between certain miRNAs and endometriosis, but the potential of these miRNAs as clinically useful biomarkers is questionable in women with infertility. Large studies in well-described patient cohorts, with rigorous methodology for miRNA expression analysis, sufficient statistical power and an independent validation step, are necessary to answer the question of whether miRNAs can be used as diagnostics markers for endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by a grant from the Research Foundation - Flanders (FWO). A.V., D.F.O. and D.P. are PhD fellows from the FWO. T.D. is vice president and Head of Global Medical Affairs Fertility, Research and Development, Merck KGaA, Darmstadt, Germany. He is also a professor in Reproductive Medicine and Biology at the Department of Development and Regeneration, Group Biomedical Sciences, KU Leuven (University of Leuven), Belgium and an adjunct professor at the Department of Obstetrics and Gynecology in the University of Yale, New Haven, USA. Neither his corporate role nor his academic roles represent a conflict of interest with respect to the work done by him for this study. The other co-authors have no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

Consensus on Recording Deep Endometriosis Surgery: the CORDES statement

STUDY QUESTION

Which essential items should be recorded before, during and after endometriosis surgery and in clinical outcome based surgical trials in patients with deep endometriosis (DE)?

SUMMARY ANSWER

A DE surgical sheet (DESS) was developed for standardized reporting of the surgical treatment of DE and an international expert consensus proposal on relevant items that should be recorded in surgical outcome trials in women with DE.

WHAT IS KNOWN ALREADY

Surgery is an important treatment for symptomatic DE. So far, data have been reported in such a way that comparison of different surgical techniques is impossible. Therefore, we present an international expert proposal for standardized reporting of surgical treatment and surgical outcome trials in women with DE.

STUDY DESIGN, SIZE, DURATION

International expert consensus based on a systematic review of literature.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Taking into account recommendations from Consolidated Standards of Reporting Trials (CONSORT), the Innovation Development Exploration Assessment and Long-term Study (IDEAL), the Initiative on Methods, Measurement and Pain Assessment in Clinical trials (IMMPACT) and the World Endometriosis Research Foundation Phenome and Biobanking Harmonisation Project (WERF EPHect), a systematic literature review on surgical treatment of DE was performed and resulted in a proposal for standardized reporting, adapted by contributions from eight members of the multidisciplinary Leuven University Hospitals Endometriosis Care Program, from 18 international experts and from audience feedback during three international meetings.

MAIN RESULTS AND THE ROLE OF CHANCE

We have developed the DESS to record in detail the surgical procedures for DE, and an international consensus on pre-, intra- and post-operative data that should be recorded in surgical outcome trials on DE.

LIMITATIONS, REASONS FOR CAUTION

The recommendations in this paper represent a consensus among international experts based on a systematic review of the literature. For several items and recommendations, high-quality RCTs were not available. Further research is needed to validate and evaluate the recommendations presented here.

WIDER IMPLICATIONS OF THE FINDINGS

This international expert consensus for standardized reporting of surgical treatment in women with DE, based on a systematic literature review and international consensus, can be used as a guideline to record and report surgical management of patients with DE and as a guideline to design, execute, interpret and compare clinical trials in this patient population.

STUDY FUNDING/COMPETING INTERESTS

None of the authors received funding for the development of this paper. M.A. reports personal fees and non-financial support from Bayer Pharma outside the submitted work; H.T. reports a grant from Pfizer and personal fees for being on the advisory board of Perrigo, Abbvie, Allergan and SPD.

TRIAL REGISTRATION NUMBER

N/A.