IVF AND PREIMPLANTATION GENETIC TESTING FOR ANEUPLOIDY (PGT-A) WHAT THE COMMUNITY PHYSICIAN NEEDS TO KNOW Jon Havelock, MD, FRCSC, FACOG Co-Director - PCRM Disclosure No conflict of interest in relation to this presentation I have received honoraria in the past 2 years from: EMD Serono Ferring Merck 2 1
Objectives 1 2 3 4 5 Describe the process of IVF and evidence for its use Review the limitations of IVF in age-related infertility Understand the biologic mechanisms for age-related infertility Discuss the role of PGT-A in IVF When should PGT be offered 3 Definitions In Vitro Fertilization (IVF) A sequence of procedures that involves extracorporeal fertilization of gametes. It includes conventional in vitro insemination and ICSI Intracytoplasmic Sperm Injection (ICSI) A procedure in which a single spermatozoon is injected into the oocyte cytoplasm Preimplantation Genetic testing (PGT) A test performed to analyze the DNA from oocytes (polar bodies) or embryos (cleavage stage or blastocyst) for HLA-typing or for determining genetic abnormalities. These include: PGT for aneuploidies (PGT-A) PGT for monogenic/single gene defects (PGT-M) PGT for chromosomal structural rearrangements (PGT-SR) Has replaced preimplantation genetic screening (PGS) or preimplantation genetic diagnosis (PGD) Zegers-Hochschild F et al. Fertil Steril 2017. 108:393-406 4 2
In Vitro Fertilization A History Lesson July 25, 1978 first IVF baby born January 24, 1992 first birth after ICSI 2010 Robert Edwards Nobel Prize in Physiology or Medicine 5 IVF Do we Have Good Evidence for its Use Only 1 RCT (Canadian) Unexplained infertility Average duration 4.5 years Average age 33 years Single IVF cycle vs 90 days expectant management NNT = 3-4 Hughes E et al. Hum Reprod 2004. 19:1105-09 6 3
IVF Treatment Why Does it Work IVF allows for additional oocytes to be produced Allows for quantitative increase in chance of conception over monofollicular ovulatory cycle Often requires multiple embryos to be transferred Multiple pregnancies 7 IVF Treatment Optimizing Success and Minimizing Risk BALANCE: obtain enough oocytes to ensure a sufficient number of embryos to transfer Too-low efficacy Target: 8 14 oocytes Risk of OHSS Pregnancy Avoid too many oocytes as this increases the risks, mainly OHSS, without an improvement in pregnancy rates De GeyterC et al. Swiss Med Wkly 2015. 145:w14087 Oocytes retrieved Adapted from Popovic-Todorovic B, et al. Hum Reprod 2003;18:2275 2282 and La Marca A, Sunkara SK. Hum Reprod Update 2014 11 8 4
Typical IVF Treatment Protocol 150-450 IU/d x 5 days 1 Gonadotropins 6 GnRH antagonist 0.25 mg Dosage Adjustment daily based on ovarian responsiveness 10-15 oocyte target hcg to induce ovulation 3 follicles 17 mm GnRH agonist trigger if >25 follicles of 12 mm each Lead follicle measures 14 mm and/or serum E 2 levels are 3000 pm BID, twice daily; ET, embryo transfer; hcg, human chorionic gonadotropin; OR, oocyte retrieval; TE, trophectoderm. Vaginal Progesterone luteal support Oocyte/embryo/ blastocyst evaluation OR, ICSI OR +5 TE biopsy and freeze all embryos if PGT-A or embryo transfer if no PGT-A β-hcg 9-11 days after ET Clinical pregnancy 6-7 weeks gestation Ongoing pregnancy 10-11 weeks gestation 9 5
How do We Identify Embryos to Transfer? Poor Quality Blastocyst Good Quality Blastocysts 11 Embryo Morphology - Selection Tool for Transfer Morphology predicts implantation Poor morphological appearing embryos do still implant Good morphological appearing embryos often do not implant Embryo selection may be enhanced by better tools for predicting implantation potential Biologic rationale for PGT-A 6
Canadian Fertility Demographics 13 Can IVF Overcome Age related Infertility? 2015 Assisted Reproductive Technology National Summary Report. US Centers for Disease Control and Prevention 14 7
Can IVF Overcome Age related Infertility? 2015 Assisted Reproductive Technology National Summary Report. US Centers for Disease Control and Prevention 15 Age-Related Infertility -Aneuploidy Franasiak et al. Fertil Steril 2014; 101:656-63 16 8
Mechanism of Aneuploidy in Embryogenesis Scott KL, et al. Fertil Steril 2013;100:608-14 17 Rationale for PGT-A Select embryos that have better implantation potential Euploid embryos Live Birth Perfect tool would allow binary determination of implantation potential Discard aneuploid embryos Potential tool with better prediction for implantation than embryo morphology No Live Birth 9
PGT-A Oocytes or embryos obtained through IVF are biopsied Embryos testing negative for disease considered for transfer Introduced in 1990 Initially for Sex selection for X-linked recessive disease 1,2 1. Verlinsky et al Hum Reprod 1990;5(7):826-829 2. Handyside et al Nature 1990;344(6268):768-770 19 Potential Benefits and Risks of PGT-A POTENTIAL BENEFITS Transfer of genetically normal embryos Increase pregnancy rates and decrease miscarriage rates Lower multiple pregnancy rates by reducing number of embryos transferred Lower need for termination of viable aneuploidies Lower risk and more acceptable Inadequate embryo numbers and/or quality No normal embryos to transfer Damage to embryos Testing a limited amount of genetic information Limits to accuracy (mosaicism, false normal and abnormals) Expense POTENTIAL RISKS 20 10
PGT-A How it works 21 PGT-A Does it Work Age < 35 acgh + Morphology Morphology P Value Number of patients receiving transfer 55 48 Oocytes Retrieved 19.5 19.3 NS Ongoing Pregnancy 38 (69.1%) 20 (41.7%) 0.009 Day 5 Blastocysts 8.3 8.1 NS Yang Z et al, Mol Cytogen2012;5:24 Q-PCR + Morphology Morphology P Value Number of patients 72 83 Oocytes Retrieved 17.2 17.1 NS Embryos transferred 1.9 2.0 0.0004 Embryos Progressing to Delivery 89/134 (66.4%) 78/163 (47.9%) 0.001 Day 5 Blastocysts 8.0 7.9 NS Scott RT et al. Fertil Steril 2013. 100:697-703 22 11
Single Embryo Transfer of Euploid Embryo Trial (StAR( StAR) ) Trial NGS Morphology P Value No Improvement in Ongoing Pregnancy Rate Per Embryo Transfer Number of patients 274 314 No Improvement in Ongoing Pregnancy Rate per Embryo Transfer for Age < 35 Years Ongoing Pregnancy - Overall 50% 46% NS Improvement in Ongoing Pregnancy Rate per Embryo Transfer for Age 35-40 Ongoing Pregnancy Age < 35 49% 53% NS Study Remains Unpublished Ongoing Pregnancy Age 35-40 51% 37% 0.04 Miscarriage Rate 10% 10% NS Illumina Website (unpublished) Co-Sponsored by Reprogenetics 23 Summary of PGT-A Trials PGT-A Morphology Relative Risk P Value Number of Embryos Transferred 463 525 Ongoing Implantation 57% 46% 1.24 <0.05 11% absolute difference in pregnancy rates Need to transfer nine PGT-A embryos to result in one additional ongoing pregnancy/live birth Does not Address Pregnancies from Subsequent Embryo Transfers from same IVF Cycle 24 12
Throwing the Baby out with the Bathwater Abnormally identified embryos very good at excluding possibility of normal pregnancy 4% of abnormally identified embryos still resulted in normal pregnancy Scott et al Fertil Steril 2012;97:870-875 25 False Abnormal Errors Mosaic Embryos? Greco E et al. N Engl J Med 2015; 373:2089-2090 26 13
False Normal Error Rate ACOG Practice Bulletin No. 163 (May 2016): Patients who conceive after preimplantation genetic screening for aneuploidy should be offered aneuploidy screening and diagnosis during their pregnancy. Werner MD et al. Fertil Steril 2014; 102:1613-18 27 PGT-A Canadian Trends Treatment Type Treatment Year 2013 2015 All ART Treatment Cycles (#) 25767 31174 Gestational Surrogacy Cycles (#) 413 639 PGT cycles (#) 371 4475 Percentage of ART Cycles that are PGD/PGS 1.4% 14% 28 14
PGT-A The Canadian Experience 29 Why Should a Patient do PGT? PGT-A - Test/tool to provide information Need to understand the limitations and false positives PGT-M Both partners carrier of AR disease or one partner has AD disease X-linked carrier HLA matching Child affected by a single gene disorder PGT-SR Identifying a known chromosomal abnormality Important points Pre-conceptional genetic counseling is important Discuss alternatives of spontaneous conception and antenatal genetic testing Need to offer confirmatory antenatal genetic testing Non-medical sex determination is illegal 30 15
Conclusions IVF is an effective fertility treatment for Severe pelvic/tubal disease Severe male factor Unexplained infertility in women under age 40 IVF does not reduce the impact of age-related infertility PGT-A may modestly improve per embryo transfer pregnancy rates Will not increase likelihood of live birth per IVF cycle started Patient best suited for PGT-A in IVF remains unclear Older patients with good ovarian response to IVF likely best Patients and clinicians need to be aware of false normal PGT-A results Prenatal genetic screening still recommended 31 Just Because You Can, Doesn t Mean You Should! 32 16