ESHRE PGD consortium data collection VII: cycles from January to December 2004 with pregnancy follow-up to October 2005

Preimplantation genetic testing for embryos predisposed to hereditary cancer: Possibilities and challenges

Preimplantation genetic testing (PGT), which was developed as an alternative to prenatal genetic testing, allows couples to avoid pregnancies with abnormal chromosomes and the subsequent termination of the affected fetus. Originally used for early onset monogenic conditions, PGT is now used to prevent various types of inherited cancer conditions based on the development of PGT technology, assisted reproductive techniques (ARTs), and in vitro fertilization (IVF). This review provides insights into the potential benefits and challenges associated with the application of PGT for hereditary cancer and provides an overview of the existing literature on this test, with a particular focus on the current challenges related to laws, ethics, counseling, and technology. Additionally, this review predicts the future potential applications of this method. Although PGT may be utilized to predict and prevent hereditary cancer, each case should be comprehensively evaluated. The motives of couples must be assessed to prevent the misuse of this technique for eugenic purposes, and non-pathogenic phenotypes must be carefully evaluated. Pathological cases that require this technology should also be carefully considered based on legal and ethical reasoning. PGT may be the preferred treatment for hereditary cancer cases; however, such cases require careful case-by-case evaluations. Therefore, this study concludes that multidisciplinary counseling and support for patients and their families are essential to ensure that PGT is a viable option that meets all legal and ethical concerns.

ESHRE PGT Consortium data collection XXI: PGT analyses in 2018

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2018 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 21st dataset on PGT are that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT-A and concurrent PGT-M/SR/A, while for PGT-M and PGT-SR, single-cell testing with PCR and FISH still prevail.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 20 datasets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN SIZE DURATION

The data for PGT analyses performed between 1 January 2018 and 31 December 2018 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using an online platform, which is based on genetic analysis and has been in use since 2016.

PARTICIPANTS/MATERIALS SETTING METHODS

Data on biopsy method, diagnostic technology, and clinical outcome were submitted by 44 centres. Records with analyses for more than one PGT for monogenic disorders (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR), or with inconsistent data regarding the PGT modality, were excluded. All transfers performed within 2 years after the analysis were included, enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, and preparation of figures and tables were carried out by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2018 covers a total of 1388 analyses for PGT-M, 462 analyses for PGT-SR, 3003 analyses for PGT for aneuploidies (PGT-A), and 338 analyses for concurrent PGT-M/SR with PGT-A.The application of blastocyst biopsy is gradually rising for PGT-M (from 19% in 2016-2017 to 33% in 2018), is status quo for PGT-SR (from 30% in 2016-2017 to 33% in 2018) and has become the most used biopsy stage for PGT-A (from 87% in 2016-2017 to 98% in 2018) and for concurrent PGT-M/SR with PGT-A (96%). The use of comprehensive, whole-genome amplification (WGA)-based diagnostic technology showed a small decrease for PGT-M (from 15% in 2016-2017 to 12% in 2018) and for PGT-SR (from 50% in 2016-2017 to 44% in 2018). Comprehensive testing was, however, the main technology for PGT-A (from 93% in 2016-2017 to 98% in 2018). WGA-based testing was also widely used for concurrent PGT-M/SR with PGT-A, as a standalone technique (74%) or in combination with PCR or FISH (24%). Trophectoderm biopsy and comprehensive testing strategies are linked with higher diagnostic efficiencies and improved clinical outcomes per embryo transfer.

LIMITATIONS REASONS FOR CAUTION

The findings apply to the data submitted by 44 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

The Consortium datasets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTERESTS

The study has no external funding, and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Effect of recombinant LH supplementation timing on clinical pregnancy outcome in long-acting GnRHa downregulated cycles

Background

Timely and moderate luteinizing hormone (LH) supplementation plays positive roles in in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) cycles with long-acting gonadotropin-releasing hormone agonist (GnRHa) pituitary downregulation. However, the appropriate timing of LH supplementation remains unclear.

Methods

We carried out a retrospective cohort study of 2226 cycles at our reproductive medicine centre from 2018 to 2020. We mainly conducted smooth curve fitting to analyse the relationship between the dominant follicle diameter when recombinant LH (rLH) was added and the clinical pregnancy outcomes (clinical pregnancy rate or early miscarriage rate). In addition, total cycles were divided into groups according to different LH levels after GnRHa and dominant follicle diameters for further analysis.

Results

Smooth curve fitting showed that with the increase in the dominant follicle diameter when rLH was added, the clinical pregnancy rate gradually increased, and the early  miscarriage rate gradually decreased.

Conclusions

In long-acting GnRHa downregulated IVF/ICSI-ET cycles, the appropriate timing of rLH supplementation has a beneficial impact on the clinical pregnancy outcome. Delaying rLH addition is conducive to the clinical pregnancy rate and reduces the risk of early miscarriage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04963-x.

ESHRE PGT Consortium data collection XIX-XX: PGT analyses from 2016 to 2017†

STUDY QUESTION

What are the trends and developments in pre-implantation genetic testing (PGT) in 2016–2017 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 19th and 20th data set on PGT are that trophectoderm biopsy has become the main biopsy stage for PGT for aneuploidies (PGT-A) and that the implementation of comprehensive testing technologies is the most advanced with PGT-A.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 18 data sets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN, SIZE, DURATION

The data for PGT analyses performed between 1 January 2016 and 31 December 2017 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using a new online platform, which is based on genetic analysis as opposed to the former cycle-based format.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on biopsy method, diagnostic technology and clinical outcome were submitted by 61 centres. Records with analyses for more than one PGT for monogenic/single gene defects (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR) indication or with inconsistent data regarding the PGT modality were excluded. All transfers performed within 2 years after the analysis were included enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, figures and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2016 to 2017 covers a total of 3098 analyses for PGT-M, 1018 analyses for PGT-SR, 4033 analyses for PGT-A and 654 analyses for concurrent PGT-M/SR with PGT-A.

The application of blastocyst biopsy is gradually rising for PGT-M (from 8–12% in 2013–2015 to 19% in 2016–2017), is status quo for PGT-R (from 22–36% in 2013–2015 to 30% in 2016–2017) and has become the preferential biopsy stage for PGT-A (from 23–36% in 2013–2015 to 87% in 2016–2017). For concurrent PGT-M/SR with PGT-A, biopsy was primarily performed at the blastocyst stage (93%). The use of comprehensive diagnostic technology showed a similar trend with a small increased use for PGT-M (from 9–12% in 2013–2015 to 15% in 2016–2017) and a status quo for PGT-SR (from 36–58% in 2013–2015 to 50% in 2016–2017). Comprehensive testing was the main technology for PGT-A (from 66–75% in 2013–2015 to 93% in 2016–2017) and for concurrent PGT-M/SR with PGT-A (93%).

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the data submitted by 61 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

Being the largest data collection on PGT in Europe/worldwide, the data sets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

ESHRE PGT Consortium data collection XVI-XVIII: cycles from 2013 to 2015

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2013–2015 as compared to previous years?

SUMMARY ANSWER

The main trends observed in the retrospective data collections 2013–2015, representing valuable data on PGT activity in (mainly) Europe, are the increased application of trophectoderm biopsy at the cost of cleavage stage biopsy and the continuing expansion of comprehensive testing technology in PGT for chromosomal structural rearrangements and for aneuploidies (PGT-SR and PGT-A).

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting data from international PGT centres. To date, 15 data sets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN, SIZE, DURATION

Collection of (mainly) European data by the PGT Consortium for ESHRE. The data for PGT cycles performed between 1 January 2013 and 31 December 2015 were provided by participating centres on a voluntary basis. For the collection of cycle, pregnancy and baby data, separate, pre-designed MS Excel tables were used.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 59, 60 and 59 centres respectively for 2013, 2014 and 2015 (full PGT Consortium members). Records with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations, figures and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XVI/XVII/XVIII, 59/60/59 centres reported data on 8164/9769/11 120 cycles with oocyte retrieval: 5020/6278/7155 cycles for PGT-A, 2026/2243/2661 cycles for PGT for monogenic/single gene defects, 1039/1189/1231 cycles for PGT-SR and 79/59/73 cycles for sexing for X-linked diseases. From 2013 until 2015, the uptake of biopsy at the blastocyst stage was mainly observed in cycles for PGT-A (from 23% to 36%) and PGT-SR (from 22% to 36%), alongside the increased application of comprehensive testing technology (from 66% to 75% in PGT-A and from 36% to 58% in PGT-SR).

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 59/60/59 participating centres and may not represent worldwide trends in PGT. Data were collected retrospectively and no details of the follow-up on PGT pregnancies and babies born were provided.

WIDER IMPLICATIONS OF THE FINDINGS

Being the largest data collection on PGT worldwide, detailed information about ongoing developments in the field is provided.

STUDY FUNDING/COMPETING INTEREST(S)

The study has no external funding and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Spinocerebellar Ataxia Patient Perceptions Regarding Reproductive Options

Background

In vitro fertilization with preimplantation genetic testing is a growing reproductive option for people who want to avoid passing a single-gene condition on to their offspring. The spinocerebellar ataxias are a group of rare, autosomal-dominant neurodegenerative disorders which are strong candidates for the use of this technology.

Objectives

This study aimed to assess knowledge of genetic risk and perceptions of reproductive options in individuals with a diagnosis of spinocerebellar ataxia.

Methods

We administered an online survey to U.S. residents of reproductive age who have been clinically or genetically diagnosed with spinocerebellar ataxia. We assessed their understanding of inheritance and their reproductive opinions.

Results

Of 94 participants, 70.2% answered all four inheritance questions correctly. The majority felt they could describe each reproductive option except prenatal diagnosis. Individuals were most interested in in vitro fertilization with preimplantation genetic testing: 48.4% (45 of 93) said they would consider it. They were least interested in prenatal diagnosis and donated embryos or gametes. Having spinocerebellar ataxia with anticipation and choosing inheritance risk as an important factor were both significantly associated with interest in preimplantation genetic testing. Choosing religion/morality as an important factor was associated with less interest in preimplantation genetic testing and prenatal diagnosis.

Conclusions

Our population displayed basic knowledge of inheritance risk, and the majority wanted to avoid having affected children. Consistent with literature for other autosomal-dominant adult-onset conditions, individuals showed a preference for preimplantation genetic testing. Health care providers should continue to educate patients about reproductive options and their risks and limitations.

Overview of Preimplantation Genetic Diagnosis (PGD): Historical Perspective and Future Direction

Preimplantation genetic diagnosis (PGD) can be considered the earliest form of prenatal testing. It was first used in humans over 26 years ago. At its inception, PGD could only be performed for a limited number of genetic disorders. Technological advances in molecular biology and cytogenomics have been utilized in the field of PGD to greatly expand the spectrum of genetic disorders that can now be detected in early human embryos.

ESHRE PGD Consortium data collection XIV-XV: cycles from January 2011 to December 2012 with pregnancy follow-up to October 2013

STUDY QUESTION

How does the data collection XIV-XV of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium compare with the cumulative data for data collections I-XIII?

SUMMARY ANSWER

The 14th and 15th retrospective collection represents valuable data on PGD/PGS cycles, pregnancies and children: the main trend observed is the increased application of array technology at the cost of FISH testing in PGS cycles and in PGD cycles for chromosomal abnormalities.

WHAT IS KNOWN ALREADY

Since 1999, the PGD Consortium has collected, analysed and published 13 previous data sets and an overview of the first 10 years of data collections.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a FileMaker Pro database (versions 5-12). Separate predesigned FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar years 2011 and 2012 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2013).

PARTICIPANTS/MATERIALS, SETTINGS, METHOD

Data were submitted by 71 centres (full PGD Consortium members). Records with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XIV-XV, 71 centres reported data for 11 637 cycles with oocyte retrieval (OR), along with details of the follow-up on 2147 pregnancies and 1755 babies born. A total of 1953 cycles to OR were reported for chromosomal abnormalities, 144 cycles to OR for sexing for X-linked diseases, 3445 cycles to OR for monogenic diseases, 6095 cycles to OR for PGS and 38 cycles to OR for social sexing. From 2010 until 2012, the use of arrays for genetic testing increased from 4% to 20% in PGS and from 6% to 13% in PGD cycles for chromosomal abnormalities; the uptake of biopsy at the blastocyst stage (from <1% up to 7%) was only observed in cycles for structural chromosomal abnormalities, alongside the application of array comparative genomic hybridization.

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 71 participating centres and may not represent worldwide trends in PGD.

WIDER IMPLICATIONS OF THE FINDINGS

The annual data collections provide an important resource for data mining and for following trends in PGD/PGS practice.

STUDY FUNDING/COMPETING INTEREST(S)

None.

Turkish University seniors' knowledge of and opinions on fertility and expectations of having children

Background

In recent years the trend of postponement of child bearing has been increasing.

Aim

To assess knowledge on fertility and expectations of having children in seniors at a Turkish University.

Methods

The cross-sectional study sample (n=485) comprised senior students of the University in the branches of medicine, social sciences, and life sciences. Data were collected via a self-administered questionnaire in 2015.

Results

The mean age of the students was 23.03±1.93 and 98.1% were unmarried. 88.45% of these students wanted to have children in the future. A higher percentage of females planned parenthood in the future than males. Males desired more children than females. Most students wanted to have their first child at age 25–29. Males wanted to have their first and last child later than did females. In case of infertility, 74.4% of females and 54.2% of males stated that they can benefit from assisted reproduction techniques. Students overestimated the success rate of assisted reproduction techniques. The percentage of students who were aware of the age at which fertility begins to decline was low.

Conclusion

The expectations of seniors at a Turkish university to have children in the future are high, with insufficient knowledge on fertility.

Preimplantation genetic screening

Preimplantation genetic diagnosis was first successfully performed in 1989 as an alternative to prenatal diagnosis for couples at risk of transmitting a genetic or chromosomal abnormality, such as cystic fibrosis, to their child. From embryos generated in vitro, biopsied cells are genetically tested. From the mid-1990s, this technology has been employed as an embryo selection tool for patients undergoing in vitro fertilisation, screening as many chromosomes as possible, in the hope that selecting chromosomally normal embryos will lead to higher implantation and decreased miscarriage rates. This procedure, preimplantation genetic screening, was initially performed using fluorescent in situ hybridisation, but 11 randomised controlled trials of screening using this technique showed no improvement in in vitro fertilisation delivery rates. Progress in genetic testing has led to the introduction of array comparative genomic hybridisation, quantitative polymerase chain reaction, and next generation sequencing for preimplantation genetic screening, and three small randomised controlled trials of preimplantation genetic screening using these new techniques indicate a modest benefit. Other trials are still in progress but, regardless of their results, preimplantation genetic screening is now being offered globally. In the near future, it is likely that sequencing will be used to screen the full genetic code of the embryo.

Causes and estimated incidences of sex-chromosome misdiagnosis in preimplantation genetic diagnosis of aneuploidy

Preimplantation genetic diagnosis of aneuploidy (PGD-A) with comprehensive chromosome analysis has been known to improve pregnancy outcomes. Accuracy in detecting sex chromosomes becomes important when selecting against embryos at risk for sex-linked disorders. A total of 21,356 PGD-A cycles consisting of day-3 (cleavage) or day-5 (blastocyst) biopsies were received at the same laboratory for PGD-A via fluorescence in situ hybridization (FISH) or array comparative genome hybridization (aCGH) from multiple fertility centres. The misdiagnosis rates were 0.12% (Wilson 95% CI 0.05 to 0.25%) in day-3 FISH cycles, 0.48% (Wilson 95% CI 0.19 to 1.22%) in day-3 aCGH cycles and 0.0% (Wilson 95% CI 0 to 0.26) in day-5 aCGH cycles. Although rare, the likely causative biological event for true misdiagnosis is embryonic XX/XY mosaicism. Reanalysis of 1219 abnormal cleavage-stage research embryos revealed a 73% incidence of minor and major mosaicism. Only four (0.3%) embryos were found to be diploid and contained XX and XY cells that could potentially account for the misdiagnosis of sex. Our investigation identified errors leading to misdiagnosis and their attribution to specific events during PGD-A testing. The reported misdiagnosis rates suggest that PGD-A for sex determination is highly accurate, particularly when using aCGH applied to blastocyst biopsies.

ESHRE PGD Consortium data collection XIII: cycles from January to December 2010 with pregnancy follow-up to October 2011

STUDY QUESTION

How do data in the 13th annual data collection (Data XIII) of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium compare with the cumulative data for collections I-XII?

SUMMARY ANSWER

The 13th retrospective collection represents valuable data on PGD/PGS cycles, pregnancies and children: the main trend observed is the decrease in the routine implementation of PGS.

WHAT IS KNOWN ALREADY

Since 1999, the PGD Consortium has collected, analysed and published 12 data sets and an overview of the first 10 years of data collections.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a FileMaker Pro database (versions 5-11). Separate predesigned FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar year 2010 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2011).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 62 centres (full PGD Consortium members). The submitted data were thoroughly analysed to identify incomplete data entries and corrections were requested from the participating centres. Records remaining with incomplete or inconsistent data were excluded from the calculations. Corrections, calculations and tables were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XIII, 62 centres reported data for 5780 cycles with oocyte retrieval (OR), along with details of the follow-up on 1503 pregnancies and 1152 babies born. A total of 1071 OR were reported for chromosomal abnormalities, 108 OR for sexing for X-linked diseases, 1574 OR for monogenic diseases, 2979 OR for preimplantation genetic screening and 48 OR for social sexing.

LIMITATIONS, REASONS FOR CAUTION

The findings apply to the 62 participating centres and may not represent worldwide trends in PGD.

WIDER IMPLICATIONS OF THE FINDINGS

The annual data collections provide an important resource for data mining and for following trends in PGD practice.

STUDY FUNDING/COMPETING INTERESTS

None.

ESHRE PGD Consortium data collection XII: cycles from January to December 2009 with pregnancy follow-up to October 2010

STUDY QUESTION

How do data in the 12th annual data collection (Data XII) of the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis (PGD) Consortium compare with the cumulative data for collections I-XI?

SUMMARY ANSWER

Since the beginning of the data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported annually.

WHAT IS KNOWN ALREADY

The PGD Consortium has collected, analysed and published 11 previous data sets since 1997.

STUDY DESIGN, SIZE, DURATION

Data were collected from each participating centre using a pre-designed FileMaker Pro database (versions 5-10). Separate FileMaker Pro files were used for the cycles, pregnancies and baby records. The study documented cycles performed during the calendar year 2009 and follow-up of the pregnancies and babies born which resulted from these cycles (until October 2010).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were submitted by 60 centres (full PGD Consortium members), and the blank files were distributed to each PGD Consortium member centre at the end of 2008. The submitted data were thoroughly analysed to identify incomplete data entries and corrections were requested from the participating centres. Records remaining with incomplete data were excluded from the calculations. Corrections, tables and calculations were made by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

For data collection XII, 60 centres reported data for 6160 cycles with oocyte retrieval (OR), along with details of the follow-up on 1607 pregnancies and 1238 babies born. A total of 870 OR were reported for chromosomal abnormalities, 113 OR for sexing for X-linked diseases, 1597 OR for monogenic diseases, 3551 OR for preimplantation genetic screening and 29 OR for social sexing.

LIMITATIONS, REASONS FOR CAUTION

These data cannot include every PGD cycle performed annually, and only indicate the trends in PGD worldwide.

WIDER IMPLICATION OF THE FINDINGS

The annual data collections provide an extremely valuable resource for data mining and for following trends in PGD practice.

STUDY FUNDING/COMPETING INTEREST(S)

None.

ESHRE PGD Consortium data collection XI: cycles from January to December 2008 with pregnancy follow-up to October 2009

The 11th report of the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis Consortium is presented, documenting cycles collected for the calendar year 2008 and follow-up of the pregnancies and babies born until October 2009 which resulted from these cycles. Since the beginning of the data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection XI, 53 centres have participated, reporting on 5641 cycles to oocyte retrieval (OR), along with details of the follow-up on 1418 pregnancies and 1169 babies born. A total of 774 OR were reported for chromosomal abnormalities, 96 OR for sexing for X-linked diseases, 1363 OR for monogenic diseases, 3401 OR for preimplantation genetic screening and 5 OR for social sexing. Data XI is compared with the cumulative data for data collections I-X.

The ESHRE PGD Consortium: 10 years of data collection

BACKGROUND

Since it was established in 1997, the ESHRE PGD Consortium has been collecting data from international preimplantation genetic diagnosis (PGD) centres. Ten papers have been published, including data from January 1997 to December 2007.

METHODS

The data collection originally used a hard-copy format, then an excel database and finally a FileMaker Pro database. The indications are divided into five categories: PGD for chromosome abnormalities, sexing for X-linked disease, PGD for single gene defects, preimplantation genetic screening (PGS) and PGD for social sexing. The main end-points are pregnancy outcome and follow-up of deliveries.

RESULTS

In data collection I, 16 centres contributed data, which increased to 57 centres by data X (average of 39 centres per data collection). These centres contributed data on over 27 000 cycles that reached oocyte retrieval. Of these cycles, 61% were for aneuploidy screening, 17% for single gene disorders, 16% for chromosomal abnormalities, 4% for sexing of X-linked disease and 2% for social sexing. Cumulatively, 5187 clinical pregnancies gave rise to 4140 deliveries and 5135 newborns (singletons: 3182, twins: 921, triplets: 37).

CONCLUSIONS

In this paper, we present an overview of the first 10 years of PGD data, highlighting trends. These include the introduction of laser-assisted biopsy, an increase in polar body and trophectoderm biopsy, new strategies, methodologies and technologies for diagnosis, including recently arrays, and the more frequent use of freezing biopsied embryos. The Consortium data reports represent a valuable resource for information about the practice of PGD.

Prenatal diagnosis: types and techniques

Up to 3% of UK pregnancies will be affected by congenital abnormality. Prenatal diagnosis allows the parents to make informed decisions about their pregnancy, healthcare professionals to optimise the antenatal care and families prepare for the birth of the baby. There are many techniques employed which range from the non-invasive ultrasonography to the highly invasive amniocentesis. This review explores the methods currently available in the UK as well as considering the newer minimally-invasive technologies available including cell-free fetal DNA and pre-implantation genetic diagnosis.

Outcomes of ovarian stimulation in a two-day oocyte collection week with PGD cycles compared to a five-day oocyte collection week with conventional IVF/ICSI cycles

We assessed the outcomes of ovarian stimulation in a two-day egg collection (EC) week with preimplantation genetic diagnosis (PGD) cycles (N = 307) compared to a five-day EC week with conventional in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles (N = 2,417). The mean (SD) age of women undergoing PGD was 34 (3.97) and 35 (3.85) for IVF/ICSI (P < 0.001), the number of oocytes collected was 13 (7.37) and 11 (7.02), (P < 0.001), while the mean (SD) number of fertilized oocytes was 8 (5.09) and 6 (4.58), respectively (P < 0.001). The clinical pregnancy rate per embryo transfer (ET) was 37% with PGD and 38% with IVF/ICSI (P = 0.49), while the implantation rate was 0.35 and 0.30, respectively (P = 0.05). After adjusting for age and confounding variables including the number of oocytes collected and fertilized normally, the mode of treatment (PGD or IVF/ICSI) had no effect on clinical pregnancy (P = 0.48). In conclusion, scheduling of PGD cycles to a two-day EC week did not compromise the outcomes of ovarian stimulation when compared to a five-day EC week with conventional IVF/ICSI cycles. This can allow the provision of a more patient friendly service, increase the flexibility of satellite PGD services, and facilitate cycle programming with the genetics team providing PGD.

Cri du chat syndrome after preimplantation genetic diagnosis for reciprocal translocation

OBJECTIVE

To report the first case of cri du chat syndrome after preimplantation genetic diagnosis (PGD) for reciprocal translocation.

DESIGN

Case report.

SETTING

In vitro fertilization center in a university affiliated hospital.

PATIENT(S)

A woman carrying a t(11;22)(q23;q11.2) translocation.

INTERVENTION(S)

Preimplantation genetic diagnosis was performed, and the woman became pregnant.

MAIN OUTCOME MEASURE(S)

Successful PGD for reciprocal translocation and diagnosis of Cri du chat syndrome for the baby.

RESULT(S)

A male baby was born at 36 weeks' gestation. However, the baby presented with a high-pitched, cat-like cry. Cytogenetic study revealed a rare case of cri du chat syndrome associated with t(11;22)(q23;q11.2) translocation.

CONCLUSION(S)

Chromosomal abnormalities, including the rare cru du chat syndrome, may occur after fluorescent in situ hybridization-based preimplantation genetic diagnosis.

Pregnancy outcome after preimplantation genetic screening or natural conception in couples with unexplained recurrent miscarriage: a systematic review of the best available evidence

The objective of this systematic review was to assess live birth rates and miscarriage rates after preimplantation genetic screening or natural conception for unexplained recurrent miscarriage. There were no randomized controlled trials or comparative studies found on this topic. Until data from randomized controlled trials become available, this review summarizes the best available evidence of the efficacy of preimplantation genetic screening vs. natural conception.

Preimplantation genetic diagnosis at 20 years

First reported in 1990, PGD has evolved into a complementary form of prenatal diagnosis offering novel indications. DNA for PGD can be recovered with equal safety and facility from polar bodies I and II, blastomere (8 cell embryo) and trophectoderm (5-6 day blastocyst). Diagnostic accuracy is very high (>99%) for both chromosomal abnormalities and single gene disorders. Traditional application of FISH with chromosome specific probes for detecting aneuploidy and translocations may be replaced or complemented by array comparative genome hybridization (array CGH); biopsied embryos can now be cryopreserved (vitrification) while analysis proceeds in orderly fashion. PGD has been accomplished for over 200 different single gene disorders. Novel indications for PGD not readily applicable by traditional prenatal genetic diagnosis include avoiding clinical pregnancy termination, performing preconceptional diagnosis (polar body I), obtaining prenatal diagnosis without disclosure of prenatal genotype (nondisclosure), diagnosing adult-onset disorders particularly cancer, and identifying HLA compatible embryos suitable for recovering umbilical cord blood stem cells.

Conceptualizing couples' decision making in PGD: emerging cognitive, emotional, and moral dimensions

OBJECTIVE

To illuminate and synthesize what is known about the underlying decision making processes surrounding couples' preimplantation genetic diagnosis (PGD) use or disuse and to formulate an initial conceptual framework that can guide future research and practice.

METHODS

This systematic review targeted empirical studies published in English from 1990 to 2008 that examined the decision making process of couples or individual partners that had used, were eligible for, or had contemplated PGD. Sixteen studies met the eligibility requirements. To provide a more comprehensive review, empirical studies that examined healthcare professionals' perceptions of couples' decision making surrounding PGD use and key publications from a variety of disciplines supplemented the analysis.

RESULTS

The conceptual framework formulated from the review demonstrates that couples' PGD decision making is composed of three iterative and dynamic dimensions: cognitive appraisals, emotional responses, and moral judgments.

CONCLUSION

Couples think critically about uncertain and probabilistic information, grapple with conflicting emotions, and incorporate moral perspectives into their decision making about whether or not to use PGD.

PRACTICE IMPLICATIONS

The quality of care and decisional support for couples who are contemplating PGD use can be improved by incorporating focused questions and discussion from each of the dimensions into counseling sessions.

ESHRE PGD Consortium data collection X: cycles from January to December 2007 with pregnancy follow-up to October 2008

The 10th report of the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium is presented, documenting cycles collected for the calendar year 2007 and follow-up of the pregnancies and babies born until October 2008 which resulted from these cycles. Since the beginning of the data collections there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection X, 57 centres participated, reporting on 5887 cycles to oocyte retrieval (OR), along with details of the follow-up on 1516 pregnancies and 1206 babies born. A total of 729 OR were reported for chromosomal abnormalities, 110 OR for sexing for X-linked diseases, 1203 OR for monogenic diseases, 3753 OR for preimplantation genetic screening and 92 OR for social sexing. Data X is compared with the cumulative data for data collections I-IX.

The single cell as a tool for genetic testing: credibility, precision, implication

PURPOSE

To investigate the influence of amplicons size and cell type on allele dropout and amplification failures in single-cell based molecular diagnosis.

METHODS

730 single lymphocytes and amniotic cells were collected from known heterozygotes individuals to one of the common Ashkenazi Jewish mutations: 1278+TATC and IVS12+1G>C which cause Tay Sachs Disease, IVS20+6T and 854A>C which underlie Familial Dysautonomia and Canavan Disease. DNA was extracted and analyzed by our routine methods.

RESULTS

Reduced rates of allele dropout and amplification failure were found when smaller amplification product were designed and in amniotic cultured cells compared to peripheral lymphocytes. Cultured lymphocytes, induced to divide, demonstrated significantly less allele dropout than non induced lymphocytes suggesting the role of division potential on amplification efficiency.

CONCLUSION

Single cell based diagnosis should be designed for each mutation. Minimal sized amplicons and cell having division potential should be preferred, as well as sensitive techniques to detect preferential amplification.

Preimplantation genetic diagnosis for haematologic conditions

PURPOSE OF REVIEW

This review will inform the clinician about the application, success rates and limitations of preimplantation genetic diagnosis (PGD) for haematologic disease to enable clinicians to offer couples with reproductive risk a realistic view of possible treatments. The molecular techniques used to diagnose disease mutations are described, including the newest technologies using whole genome amplification (WGA) and preimplantation genetic haplotyping (PGH) of embryos. The history and ethics involved in performing PGD together with human leukocyte antigen (HLA) testing (PGD-H) to create matched siblings suitable for haematopoietic stem cell transplant (HSCT) are discussed.

RECENT FINDINGS

The greatest diagnostic hurdle in PGD is the paucity of molecular material in the single embryonic cell. WGA allows amplification of the entire genome, which greatly simplifies mutation analysis and increases the possibilities of multiple simultaneous genetic diagnoses. PGH can be applied to the amplified material, and may enable the application of PGD to the less common haematological mutations, and the diagnosis of nonaffected male progeny in cases of X-linked haematologic diseases.

SUMMARY

PGD to exclude embryos carrying serious haematologic disease is a viable alternative to prenatal diagnosis for couples who wish to avoid having affected children and for whom therapeutic termination of affected pregnancies is unacceptable. PGD is not available for all haematologic mutations, is expensive, time consuming and does not guarantee a pregnancy. PGD-H is more diagnostically and ethically challenging, especially when there is the time constraint of urgent provision of HLA-matched stem cells for a sick sibling. To date there is only a handful of reported cases of successful HSCT from siblings created by embryo selection. The evolving technology of PGH following WGA may increase the diagnostic scope and availability of PGD in the future, but certain limitations will remain.

Preimplantation genetic diagnosis for the prevention of sickle cell disease: current trends and barriers to uptake in a London teaching hospital

INTRODUCTION

Sickle cell disease (SCD) is a clinically significant hemoglobinopathy with increasing global incidence. We describe our experience of using pre-implantation genetic diagnosis (PGD) for the prevention of SCD at a tertiary referral centre in London.

METHODS

Between January 2002 and December 2007, of 78 at-risk couples referred for PGD treatment, 12 couples (15%) underwent 16 PGD cycles for the prevention of SCD. RESULTS. The live birth rate was 13% per initiated cycle, 18% per embryo transfer and 17% per couple.

CONCLUSIONS

Although PGD for prevention of the birth of a child affected by SCD is a viable treatment option for couples at risk of having an affected child, potential barriers to uptake of this service need to be fully addressed to ensure its availability to all couples seeking to avoid having a child affected with SCD.

Preimplantation genetic diagnosis (PGD) for nonsyndromic deafness by polar body and blastomere biopsy

PURPOSE

Development of an efficient and reliable PGD protocol for nonsyndromic deafness, by polar body (PB) and blastomere PGD.

METHODS

The GJB2/GJB6 mutations along with 12 polymorphic markers were used in PGD analysis of blastomeres or polar bodies in 14 couples for 35 cycles. Marker informativity, diagnosis rates, Allele Drop Out (ADO) rates and PB1 heterozygosity rates were assessed.

RESULTS

Six cycles were performed by PB biopsy, 27 by blastomere and two combined cycles, resulting in delivery of three unaffected children and five ongoing pregnancies. Diagnosis rates for PB and blastomeres were similar. Only 17% PB1s were heterozygote. ADO rates of 19% were observed in both groups.

CONCLUSIONS

We have developed a single cell multiplex PGD protocol for nonsyndromic deafness with a high efficiency of diagnosis. Most PB1 are homozygous, and similar ADO rates were observed; therefore, blastomere biopsy appears to be the method of choice for this autosomal recessive disease.

Impact of cleavage-stage embryo biopsy in view of PGD on human blastocyst implantation: a prospective cohort of single embryo transfers

BACKGROUND

Human embryo biopsy is performed for preimplantation genetic diagnosis (PGD). The impact of 1- or 2-cell removal at cleavage-stage on future embryo development and implantation capacity is highly debated.

METHODS

In order to explore this issue further, a cohort of Day 5 single embryo transfers was analysed prospectively for embryological and clinical outcome. All transferred embryos resulted from 8-cell embryos on Day 3, from which subsequently either one cell (group I, n = 182) or two cells (group II, n = 259) were removed, or on which no invasion by means of embryo biopsy was performed (group III, control group, n = 702). RESULTS Blastocyst formation was significantly better in group III compared with group II, and similar to group I. Group I and group II did not differ in Day 3 nor in Day 5 embryo development. The overall live birth rate was significantly higher in group I (37.4%, CI 29.0-47.4%) than in group II (22.4%, CI 17.0-28.9%), and comparable to the reference ICSI population (35.0%, CI 30.8-39.7%).

CONCLUSIONS

The clinical outcome of 1-cell biopsy was significantly better than that of 2-cell biopsy, even when adjusted for availability of genetically transferable embryos.

Incidence of chromosomal mosaicism in morphologically normal nonhuman primate preimplantation embryos

OBJECTIVE

To establish the exact rates of chromosomal mosaicism in morphologically normal rhesus macaque embryos by determining the chromosomal complement of all blastomeres.

DESIGN

Retrospective rhesus monkey IVF study.

SETTING

Academic laboratory and primate research center.

PATIENT(S)

Young fertile rhesus macaque females.

INTERVENTION(S)

Morphologically normal in vitro-produced rhesus macaque embryos were dissociated and cytogenetically assessed using a five-color fluorescent in situ hybridization assay developed for rhesus macaque chromosomes homologous to human chromosomes 13, 16, 18, X, and Y.

MAIN OUTCOME MEASURE(S)

The incidence and extent of chromosomal mosaicism in rhesus macaque preimplantation embryos.

RESULT(S)

Seventy-seven preimplantation embryos, displaying normal morphology and development, from 17 young rhesus macaque females were analyzed. Overall, 39 embryos (50.6%) were normal, 14 embryos (18.2%) were completely abnormal, and 24 embryos (31.2%) were mosaic. Of the 226 blastomeres analyzed in the mosaic group, 110 blastomeres (48.7%) were normal.

CONCLUSION(S)

The observed rate of mosaicism in good-quality rhesus embryos resembles previously documented frequencies in poor-quality human preimplantation embryos. A high incidence of mosaicism may limit the diagnostic accuracy of preimplantation genetic diagnosis.

Preimplantation genetic diagnosis for mitochondrial DNA disorders: ethical guidance for clinical practice

Although morally acceptable in theory, preimplantation genetic diagnosis (PGD) for mitochondrial DNA (mtDNA) disorders raises several ethical questions in clinical practice. This paper discusses the major conditions for good clinical practice. Our starting point is that PGD for mtDNA mutations should as far as possible be embedded in a scientific research protocol. For every clinical application of PGD for mtDNA disorders, it is not only important to avoid a 'high risk of serious harm' to the future child, but also to consider to what extent it would be possible, desirable and proportional to try to reduce the health risks and minimize harm. The first issue we discuss is oocyte sampling, which may point out whether PGD is feasible for a specific couple. The second issue is whether one blastomere represents the genetic composition of the embryo as a whole -- and how this could (or should) be investigated. The third issue regards the cutoff points below which embryos are considered to be eligible for transfer. We scrutinize how to determine these cutoff points and how to use these cutoff points in clinical practice -- for example, when parents ask to take more or less risks. The fourth issue regards the number of cycles that can (or should) justifiably be carried out to find the best possible embryo. Fifth, we discuss whether follow-up studies should be conducted, particularly the genetic testing of children born after IVF/PGD. Finally, we offer the main information that is required to obtain a truly informed consent.

A cost-benefit analysis of preimplantation genetic diagnosis for carrier couples of cystic fibrosis

OBJECTIVE

To perform a cost-benefit analysis of preimplantation genetic diagnosis (PGD) for carrier couples of cystic fibrosis (CF) compared with the alternative of natural conception (NC) followed by prenatal testing and termination of affected pregnancies.

DESIGN

Cost-benefit analysis using a decision analytic model.

SETTING

Outpatient reproductive health practices.

PATIENT(S)

A simulated cohort of 1,000 female patients.

INTERVENTION(S)

We calculated the net benefit of giving birth to a child as the present value of lifetime earnings minus lifetime medical costs.

MAIN OUTCOME MEASURE(S)

Net benefits in dollars.

RESULT(S)

When used for women younger than 35 years of age, the net benefit of PGD over NC was $182,000 ($715,000 vs. $532,000, respectively). For women aged 35-40 years, the net benefit of PGD over NC was $114,000 ($634,000 vs. $520,000, respectively). For women older than 40 years, however, the net benefit of PGD over NC was -$148,000 ($302,000 vs. $450,000, respectively).

CONCLUSION(S)

Preimplantation genetic diagnosis provides net economic benefits when used by carrier couples of CF. Although there is an upper limit of maternal age at which economic benefit can be demonstrated, carrier couples of CF should be offered PGD for prevention of an affected child.

Technology requirements for preimplantation genetic diagnosis to improve assisted reproduction outcomes

Preimplantation genetic diagnosis has been proposed as a method to improve assisted reproduction technology outcomes, but different techniques have produced conflicting results. The use of appropriate techniques may provide positive outcomes.

ESHRE PGD Consortium data collection IX: cycles from January to December 2006 with pregnancy follow-up to October 2007

The ninth report of the European Society of Human Reproduction and Embryology Preimplantation Genetic Diagnosis Consortium is presented documenting cycles collected for the calendar year 2006 and follow-up of the pregnancies and babies born until October 2007, which resulted from these cycles. Since the beginning of the data collections there has been a steady increase in the number of cycles, pregnancies and babies reported annually. For data collection IX, 57 centres have participated, reporting on 5858 cycles to oocyte retrieval (OR), along with details of the follow-up on 1437 pregnancies and 1206 babies born. Eight hundred and twelve ORs were reported for chromosomal abnormalities, 133 ORs for sexing for X-linked diseases, 931 ORs for monogenic diseases, 3900 ORs for preimplantation genetic screening and 82 ORs for social sexing. Data IX are compared with the cumulative data for data collections I-VIII.

Quality management system in PGD/PGS: now is the time

PURPOSE

Governments and international authorities require an accreditation of the PGD/PGS laboratories in order to ensure the safety and reproducibility of these analytical procedures. The implementation of a Quality Management System is the first mandatory step prior to accreditation. Our aim is to offer a detailed guidance to the PGD/PGS community that would like to implement this system in the future.

METHODS

The certification was based on the norm ISO 9001:2000 and requires the identification of procedures, definition of the flowchart, documentation of the processes, recognition of the critical control points, establishment of quality controls, performance of validation and audit system.

RESULTS

The achievement of ISO certification with the specific scope of "preimplantation genetic diagnosis".

CONCLUSION

Certification of PGD/PGS allows to achieve evaluation of the efficiency to ensure the sensitivity and a continuous improvement of the genetic diagnosis of embryonic single cells.