Advances and Challenges in PGD and PGS. Hsin-Yang Li, MD, PhD

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1 Advances and Challenges in PGD and PGS Hsin-Yang Li, MD, PhD Taipei, Taiwan

2 Oral Session 9: ESHRE data reporting on PGD cycles and oocyte donation Data from the ESHRE PGD Consortium Joanne Traeger-Synodinos and colleagues University of Athens Department of Medical Genetics Athens, Greece

3 The Role of the ESHRE PGD Consortium Actively collects data on PGD and PGS each year Several Working Groups: Data collection Creation of online database and data mining Promoting high standards in PGD and accreditation Evaluating PGD/PGS through audit Sharing of molecular methods Support of a forum for PGD centers to exchange information and address problem solving Traeger-Synodinos et al. ESHRE Oral 041

4 ESHRE PGD consortium: global initiative collecting data on accuracy, reliability, effectiveness and safety of PGD Europe Sweden Finland North and South America Ireland Scotland UK Denmark Netherlands Germany Belgium Poland Czech Rep Ukraine Africa, Asia, Australia and Russia Canada France Switzerland Austria Hungary Serbia Russia North America South America Portugal Spain Italy Greece Bulgaria Africa Turkey Egypt Pakistan UAE (United Arab Emirates) Asia India Thailand? South Korea? Philippines? Japan? Yemen? Brazil Argentina Number of centers: 83 Singapore Australia South Africa Number of centers: 11 Number of centers: 28 Traeger-Synodinos et al. ESHRE Oral 041

5 Data Collected The Consortium has analyzed 14 sets of data with indications including: Inherited chromosomal abnormalities Monogenic disorders Sexing for X-linked diseases Social reasons Aneuploidy screening for infertility Findings: Methods for biopsy have changed gradual increase in polar body and blastocyst biopsy Methods for diagnosis of monogenic PGD are evolving The number of PGS cycles has dropped in the last 5 years Traeger-Synodinos et al. ESHRE Oral 041

6 Other Consortium Activities Several quality standards and accreditation schemes have been initiated The Misdiagnosis Monitoring and Audit Working Group has submitted a paper on the data collected on embryo follow-up after amplification-based PGD The Molecular Methods Working Group has developed a primer database for sharing validated primers The Information Exchange and Education Working Group ran a successful pilot of webinarbased tools Traeger-Synodinos et al. ESHRE Oral 041

7 Oral Session 31: PGD/PGS Euploid embryos are far more likely to undergo blastulation than aneuploidy embryos when based on single blastomere array Comparative Genome Hybridisation (CGH) Mario Vega and colleagues Continuum Reproductive Center St. Luke's-Roosevelt Hospital Center Obstetrics and Gynecology New York, U.S.A.

8 Introduction Is blastulation rate associated with euploid embryo status? Vega et al. ESHRE Oral 117

9 Introduction (con t.) Trophoectoderm biopsies show a higher rate of euploid embryos at the blastocyst stage than the euploid rate as previously reported from cleavage stage blastomere biopsies Historically, it has been thought that aneuploidy embryos are just as likely to undergo blastulation as euploid embryos Vega et al. ESHRE Oral 117

10 Methods Retrospective cohort study performed on 44 IVF cycles between January 2011 and December 2012 Day 3 single cell blastomere biopsy with array CGH and PGS Primary objective: assess hypothesis that blastulation rate is higher among euploid than aneuploidy embryos Secondary objective: assess the effect of Day 3 blastomere biopsy on the development of all blastocysts, and fully expanded or hatching blastocysts Vega et al. ESHRE Oral 117

11 Results: Blastulation Rate Key point: Blastulation rate is 3 times greater in euploid than aneuploid embryos Vega et al. ESHRE Oral 117

12 Results (con t.) Fully Expanded or Hatching Blastocysts Key point: Expansion and hatching rates are higher in euploid embryos Vega et al. ESHRE Oral 117

13 Conclusions Euploid embryos appear 3 times more likely to undergo blastulation than aneuploid embryos Expansion and hatching rates are higher in euploid embryos Study limitation: Retrospective design; small study group; mosaicism in single cell biopsy could affect outcomes Vega et al. ESHRE Oral 117

14 Oral Session 31: PGD/PGS Preimplantation genetic screening on day 3 embryos using array comparative genomic hybridisation in patients with advanced maternal age: a prospective double blinded randomized controlled trial Francesco Fiorentino and colleagues GENOMA - Molecular Genetics Laboratory Preimplantation Genetic Diagnosis Centre Rome, Italy

15 Introduction Does cleavage stage PGS using array comparative genomic hybridisation (CGH) improve the clinical outcome of IVF techniques in patients of advanced maternal age? Fiorentino et al. ESHRE Oral 118

16 Introduction (con t.) PGS studies demonstrated a high prevalence of aneuploidy in human embryos Screening for aneuploidy using fluorescence in situ hybridisation (FISH)-based PCS on cleavage stage embryos failed to improve live birth rate Technical limitations of the FISH technology may be the main reason for this poor clinical performance The primary objective of this study was to assess whether PGS on cleavage stage embryos using array CGH improves the clinical outcome of IVF techniques in patients of advanced maternal age Fiorentino et al. ESHRE Oral 118

17 Methods Prospective, double blinded, randomized controlled trial (ISRCTN ) Inclusion criteria: Female patients aged between 36 and 43 years; History of <3 miscarriages and <3 failed IVF/ICSI cycles 6 MII oocytes retrieved Randomization: Control group (A): n=34 ICSI procedure transfer up to 2 embryos at Day 5 Study group (B): n=31 ICSI procedure one-cell embryo biopsy on Day 3 PGS by array-cgh transfer up to 2 euploid embryos at day 5 Fiorentino et al. ESHRE Oral 118

18 Results PGS and implantation rates in fresh cycles Key point: PGS at cleavage stage improves implantation rates in fresh cycles Fiorentino et al. ESHRE Oral 118

19 Results (con t.) PGS and implantation rates in cumulative cycles Key point: PGS at cleavage stage improves implantation rates in cumulative cycles Fiorentino et al. ESHRE Oral 118

20 Conclusions PGS at cleavage stage improves the implantation rate in patients of advanced maternal age PGS does not increase pregnancy rates per patient There is a higher risk of misdiagnosis due to mosaicism than with current blastocyst biopsy strategy This led to early termination of the study Fiorentino et al. ESHRE Oral 118

21 P-463 Does preimplantation genetic screening (PGS) really improve implantation rate? Comparison of frozen-thawed embryo transfers between patients undergoing PGS and those without genetic screening Patrizia Rubino and colleagues Ferticlinic-Villa Margherita Laboratorio PMA Roma, Italy

22 Introduction Is PGS a real improvement? The implantation rates of frozen-thawed embryo replacement cycles of patients undergoing PGS by array-cgh were compared with those undergoing normal frozen-thawed replacement cycles. Rubino et al. ESHRE Poster 463

23 Introduction (con t.) There are several reports that Preimplantation Genetic Screening (PGS) improves clinical outcomes The majority of these make the comparison between frozen-thawed PGS cycles and fresh cycles without PGS However, evidence during past years have reported equal or even higher pregnancy rates of frozen-thawed embryo transfers compared to those obtained after fresh embryo transfers Rubino et al. ESHRE Poster 463

24 Methods Retrospective cohort study Examined all the frozen-thawed embryo replacement cycles performed in a single center from January to December 2012 All the embryos were at the blastocyst stage Array-CGH analysis was used After thawing, embryos were cultured for 2 to 4 hours to assess embryo viability before they were transferred Only single embryo transfers SET were made in PGS cycles (in this center) Rubino et al. ESHRE Poster 463

25 Results Frozenthawed cycles (n=39) Frozenthawed PGS cycles (n=14) Mean age P=0.5 Clinical Pregnancy Rate 33.3% 53.3% P=0.22 Cumulative Pregnancy Rate 37.0% 66.6% P=0.09 Ongoing implantation rate 38.5% 53.3% P=0.01 Key point: A significantly higher implantation rate was observed in the frozen-thawed PGS cycles than in frozen-thawed cycles not undergoing PGS Rubino et al. ESHRE Poster 463

26 Conclusions Transferring euploid embryos significantly increases the chances of implantation, even when performing SET Thereby circumventing the risk of twin pregnancies These results demonstrate that selecting euploid embryos for transfer improves the chance of achieving a pregnancy Study limitation: The number of patients was limited. The embryos transferred in frozen-thawed cycles were often not morphologically optimal since those were chosen for fresh cycles. Rubino et al. ESHRE Poster 463

27 Oral Session 31: PGD/PGS Is cohort size of euploid blastocysts following comprehensive chromosomal screening predictive of improved outcomes in single embryo transfer cycles? Scott Morin and colleagues NYU Langone Medical Center NYU Fertility Center New York, U.S.A.

28 Introduction Can the quantity of euploid blastocysts in a given cohort be used to identify the best candidates for single embryo transfer (SET) while maintaining a high clinical pregnancy rate and reducing the risk of multiple pregnancy? Morin et al. ESHRE Oral 121

29 Introduction (con t.) In the USA, 88% of ART cycles involve transfer of two or more embryos, resulting in a multiple pregnancy rate of 27.5% Trophoectoderm biopsy followed by comprehensive chromosomal screening (CCS) is superior to morphology assessment in identifying embryos for single embryo transfer (SET) No study has examined whether the number of euploid embryos in a cohort is associated with improved outcomes following SET Morin et al. ESHRE Oral 121

30 Methods Multicenter retrospective analysis Study design and population: 297 patients referred for chromosomal screening underwent SET or DET (non-randomized) after confirmation of at least one euploid embryo Average age 34.7 years Most common diagnoses: Recurrent pregnancy loss Advanced maternal age Multiple IVF failures Number of euploid blastocysts produced per cohort was recorded Study outcomes included: Clinical pregnancy rate Multiple gestation rate Morin et al. ESHRE Oral 121

31 Results Patients with 3 euploid blastocysts (n=168) # ET Clinical pregnancy rate n (%) Multiple gestation (n) MGR/pregnancy (%) 1 47/111 (42.3) /57 (64.9) p-value <0.01 <0.001 <0.001 Key point: In patients with 3 euploid blastocysts, DET increases the pregnancy rate but also increases the risk of multiple pregnancy Morin et al. ESHRE Oral 121

32 Results (con t.) Patients with 4 euploid blastocysts (n=129) # ET Clinical pregnancy rate n (%) Multiple gestation (n) MGR/pregnancy (%) 1 41/55 (74.5) /74 (78.4) p-value 0.6 < <0.001 Key point: In patients with 4 euploid blastocysts, there is no difference in clinical pregnancy rate between SET or DET but the risk of multiple pregnancy is higher with DET Morin et al. ESHRE Oral 121

33 Conclusions Patients who produce 3 euploid blastocysts are more likely to achieve pregnancy with DET However the risk of multiple pregnancy is higher than with SET Patients who produce 4 euploid blastocysts are just as likely to achieve pregnancy with SET as with DET However the risk of multiple pregnancy is 5 times higher with DET Patients who produce at least 4 euploid embryos are good candidates for SET Morin et al. ESHRE Oral 121

34 Oral Session 31: PGD/PGS Re-analysis of whole day 5 embryos using the same array CGH platform used for single cell day 3 diagnosis showed a high confirmation rate Pere Mir and colleagues IVIOMICS S.L. PGD Molecular Genetics Valencia, Spain

35 Introduction Is Day 3 PGS by array CGH representative of the whole embryo regarding concordance between Day 3 single cell analysis and Day 5 re-analysis of the whole embryo using the same array CGH platform? Mir et al. ESHRE Oral 122

36 Introduction (con t.) Meiotic or mitotic errors during embryo development lead to embryo aneuploidies Mosaicism has been observed at cleavage and also at blastocyst stage It has been widely discussed that Day 3 embryo biopsy could not have a role for PGS because analysis of a single cell is not representative of all the embryo due to embryo mosaicism at the cleavage stage Mir et al. ESHRE Oral 122

37 Methods Prospective blinded study to re-analyze embryos previously diagnosed as chromosomally abnormal by Day 3 array CGH Using Day 5 array CGH of the whole embryo Day 3 and Day 5 were compared Same protocol was used at both time points 50 embryos analyses Study from October 2012 to December 2012 Mir et al. ESHRE Oral 122

38 Results Key point: The confirmation rate between Day 3 biopsy and Day 5 whole embryo analysis was high Mir et al. ESHRE Oral 122

39 Results (con t.) Key point: This Day-5 embryo was mosaic with monosomy 18 + normal cells Mir et al. ESHRE Oral 122

40 Conclusions Day 3 array CGH diagnosis is highly confirmed by Day 5 re-analysis of the whole embryo using the same protocol The high confirmation rate suggests that Day 3 diagnosis is representative of the whole embryo An accurate diagnosis for PGS can thus be performed with Day 3 array CGH Study limitation: Low degree of mosaicism (25-30%) cannot be detected by array CGH on Day 5 biopsies Mir et al. ESHRE Oral 122

41 Oral Session 31: PGD/PGS Non-reciprocal errors and germinal mosaicism detected by the application of array-cgh to oocyte and polar bodies unexposed to sperm H. Ghevaria and colleagues H. Ghevaria and colleagues Institute for Women's Health UCL Centre for PGD London, United Kingdom

42 Introduction In women of average maternal age what is the incidence of chromosome versus chromatid anomalies in oogenesis, how common are non-reciprocal errors and how common is germinal mosaicism? Ghevaria et al. ESHRE Oral 119

43 Introduction (con t.) Two predominant aneuploidy causing mechanisms have been shown to exist in female meiosis Whole chromosome non-disjunction Premature separation of chromatids Array CGH testing of polar bodies showed that, in women of advanced maternal age, most anomalies are due to premature separation of chromatids Previous research using different techniques gave more mixed results Polar body testing has been shown to be the least reliable technique compared with blastomere or trophoectoderm biopsy, although the reason why is unclear Ghevaria et al. ESHRE Oral 119

44 Methods 89 unfertilized oocytes at different stages of maturation were obtained 84 gave results Oocytes were analyzed by whole genome amplification and array CGH Ghevaria et al. ESHRE Oral 119

45 Results Key point: Chromatid abnormalities are more common than chromosome abnormalities in unfertilized oocytes Ghevaria et al. ESHRE Oral 119

46 Results (con t.) GV oocytes: 17/17 were euploid MI oocytes: 18/21 were euploid 3/21 were aneuploid (2 oocytes had chromatid errors and 1 oocyte had chromosome errors)

47 Conclusions Chromatid abnormalities are more common than chromosome abnormalities in unfertilized oocytes Overall aneuploidy rate of all oocytes across all stages = 23/84 (27%) Chromatid errors: 65% (15/23) Chromosome errors: 17% (4/23) Both errors: 13% (3/23) Non-reciprocal errors and germinal mosaicism were detected in oocytes Ghevaria et al. ESHRE Oral 119

48 P-448 Effect of chromosome polymorphic variants on infertility and the relationship with IVF cycle outcome Ruth Morales and colleagues Instituto Bernabeu Biotech Molecular Biology Alicante, Spain

49 Introduction Is there a correlation between chromosome polymorphic variants and the infertile phenotype, and is there an association with IVF cycle outcome? Morales et al. ESHRE Poster 448

50 Introduction (con t.) Structural chromosomal abnormalities are a common genetic failure in humans and are responsible for reproductive problems such as infertility and recurrent pregnancy loss (RPL) Polymorphic variants on chromosomes involving heterochromatic regions appear to occur in the general population without clinical significance However the incidence of these variants is higher in patients with RPL or men with poor sperm quality Morales et al. ESHRE Poster 448

51 Methods Cytogenetic studies of 866 infertile patients and 685 sperm/oocyte donor controls Rate of aneuploidy spermatozoa evaluated using fluorescence in situ hybridization (FISH) in 145 infertile men Using probes for chromosomes X, Y, 18, 13 and 21) Outcome of IVF cycles analyzed (n=259 patients) Main cycle outcome measures were biochemical and clinical miscarriage rates Morales et al. ESHRE Poster 448

52 Results Frequencies of chromosome variants in control and study group Polymorphism Inv(9) 9qh+ 9qh- 1qh+ 16qh+ Yqh+ 21ps+ 22ps+ 13ps+ 14ps+ 15ps+ Controls (n=685) Patients (n=866) p 0.49 < < Frequency of variants among patients with RPL was 24.1% compared with 12.8% in controls (p<0.05) Key point: Chromosome polymorphic variants were more prevalent in the infertile than the control group, especially patients with RPL Morales et al. ESHRE Poster 448

53 Results (con t.) Significant differences were observed in rate of aneuploid spermatozoa between infertile men with and without polymorphisms Aneuploidy rate in infertile men with polymorphisms = 37.7% Aneuploidy rate in infertile men without polymorphisms = 16.3% (p<0.05) Sperm count was unaffected Key point: Men carrying polymorphisms have a higher incidence of sperm aneuploidies Morales et al. ESHRE Poster 448

54 Results (con t.) IVF cycle outcomes between groups of patients without RPL Patients carrying polymorphism Patients with normal karyotype Fertilization rate (%) NS Implantation rate (%) NS A+B embryos (%) NS Pregnancy rate (%) NS Biochemical miscarriage rate (%) NS Clinical miscarriage rate (%) NS P Key point: Patients with polymorphisms and undergoing an IVF cycle appear to be at a higher risk of miscarriage (P=NS) Morales et al. ESHRE Poster 448

55 Conclusions Chromosome polymorphic variants are more prevalent in the infertile population than normal controls Sperm aneuploidy rates are higher in men with polymorphisms Patients with polymorphisms appear to be more likely to suffer pregnancy loss after IVF Chromosome polymorphic variants are associated with infertility in both men and women and should be considered before fertility treatment Study limitation: The role of these variants in infertility has not been investigated Morales et al. ESHRE Poster 448