Transcript PPT File

Clinical Management of
In Vitro Fertilization With
Preimplantation Genetic Diagnosis
Ilan Tur-Kaspa, M.D.,
Seminars in Reproductive Medicine,
2012;30(4):309-322
R4 孫怡虹/Dr.蔡永杰
INTRODUCTION
Preimplantation genetic diagnosis (PGD)
• Introduced in 1990 by Verlinsky et al in Chicago with
polar body biopsy
• In London by Handyside et al that same year with
blastomere biopsy
• Indications: expanded rapidly
Conceive with healthy embryos tested in vitro before
implantation  avoid the dilemma of whether or not
to terminate a pregnancy or deliver a sick child
Preimplantation genetic diagnosis (PGD)
• For couples at risk of having children with heritable
and debilitating genetic diseases:
 A major scientific advance
• For couples who carry a balanced chromosomal
translocation:
 Significantly ↓ the risk of spontaneous
miscarriage (~ <20%) & ↑ live-birth rates
Discussion in this article
• The safety of PGD procedures
• Children's outcome
• How to optimize ovarian stimulation and PGD
success
• Daily routine of clinical management of IVF for PGD
– Special clinical dilemmas
– Protocols such as nondisclosure PGD
Is PGD Safe?
EMBRYO DEVELOPMENT, PREGNANCY RATES, AND
CHILDREN BORN AFTER PGD
• Ovarian stimulation for IVF with PGD
• Embryo micromanipulation
• Technique used for biopsy
• Numbers of cells removed from the embryo
May affect embryo development, implantation rate,
& the pregnancy outcome
Implantation rates of embryos
• After Biopsy of polar bodies ( 4 h after oocyte
retrieval) + embryo  blastomere (6~8 cells, 72 h or
D3 of embryo culture)
Similar (26%  25%) regardless of the number of
micromanipulations performed
Embryo development
• 9925 embryos biopsied for PGD  28,126 non-biopsy
ICSI embryos: Similar blastocysts development rates
• Breaching of the zona pellucida and by removing only 1
blastomere from day 3 embryos
– Live-birth rate significantly ↑
– Removing 2 cells  affect embryo development
significantly  should be stopped
• Holes created in the zona pellucida for PGD  ↑
incidents of monozygotic twins (at experienced
centers)
Initial ↓ [β-hCG] with pregnancies
obtained after PGD
Control: Biochemical pregnancy rate, clinical miscarriage
rate, take-home infant rate: Similar in both groups
• May result from the blastomere biopsy
– ↓ β-hCG-producing activity of the trophoblast,
especially at early pregnancy
– A delayed implantation
• May occur in biopsied embryos
• Or related to the type of controlled ovarian
hyperstimulation (COH)
 May be clinically implemented for predicting successful
pregnancy outcome following PGD procedure
• Reproductive specialist experienced in IVF with PGD
+ Skilled embryologists & PGD laboratory (including
removal of only 1 cell from day 3 embryos)
May obtain high pregnancy rates
** European Society of Human Reproduction &
Embryology (ESHRE)  Some centers in the United
States
Children born after PGD
 Natural conception or IVF/ICSI
• Mental & psychomotor development (age 2~4)
– Similar developmental outcomes
• ↑ Rate of malformation or neonatal problems
• Adverse effects: congenital malformations,
growth, neonatal intensive care admissions,
behavior, or mental & psychomotor development
• Infertility: Independent factor affecting children's
health with or without ART
( PGD, without infertility  IVF/ICSI-only: if ↓ rate
of malformation or neonatal problems)
Children born after PGD
 Natural conception or IVF/ICSI
• PGS children: showed an unexplained lower
neurological optimality scores (Middelburg et al)
• ↑ Rate of stillbirths in multiple pregnancies
following PGD (From one center that used to remove
2 cells for biopsy)
Summary
• PGD in experienced laboratories seems to be safe
• Similar clinical outcomes as with regular ART
• Embryo biopsy:
– Performed on day 3
– Only one cell should be removed for PGD/PGS
– Not add risk factors to the health of singleton
children born after PGD or PGS
– Need Further prospective follow-up studies
How to Maximize IVF-PGD Outcome
Factors that influence pregnancy & live birth rate
• Patient related (outside a fertility clinic's control):
– Age, infertility diagnosis, Hx of previous births, previous
miscarriages, previous failed ART cycles
• PGD  Embryo:
– Aavailable for transfer: ↓ 25 ~ 81%
– 25% with recessive single-gene disorders; 50% with
dominant mutations; 30 ~ 70% (depending on age) with
aneuploid; 75% with unbalanced translocation
– 81%: not be suitable for ET (PGD for HLA matching +
recessive mutation)
• Genetic status  Response to ovarian stimulation
Evaluation before IVF
1. Infertility Diagnosis (other than genetic analysis)
– Severe male factor, Endometriosis, Hydrosalpinx, Low
ovarian reserve
– Embryo development after ICSI is different
• To avoid DNA contamination when molecular genetics
is planned  For severe male factor
– Sperm quality  Aneuploidy rate in embryos
– Social habits (smoking, drinking, drug)  ART result
2. Ovarian reserve: using age, antral follicle count and/or antiMüllerian hormone, day 3 FSH levels
3. Unsuspected uterine cavity abnormality (11 ~ 22%):
Polyps, Submucosal fibroids, Intrauterine adhesions
Ovarian Stimulation
Is There an Optimal Number of Oocytes to Start ART?
• Optimal number of oocytes retrieved: 10 ~ 15
Mild ovarian stimulation  ↓ Pregnancy rates
• PGD results ↓ 25 ~ 81 % embryo for transfer
• ↓Number of OR  associated with a fair chance for ET
& pregnancy, esp. in young patients (<35 y/o)
Low number of oocytes/embryo  Canceling of cycles
should be reconsidered
• Implantation and delivery rates: ↑↑ in the group that
continued with the PGS
Canceling PGD may be abandoned in most cases
Ovarian Stimulation and Aneuploidy
• Inadequate stimulation and/or poor PGS/PGD
techniques may indeed affect cycle outcome
• Exogenous FSH administration  risk of human
embryonic aneuploidy
• The use of GnRH antagonists with COH was
suggested as a more patient-friendly protocol
• Type of gonadotropins / GnRH analogs used for
ovarian stimulation protocols / the number of
oocytes retrieved  Affect embryos' aneuploidy
rate: Insufficient evidence
Genetic Status of the Woman and Her Response
to Controlled Ovarian Hyperstimulation
• Numbers of oocytes: a significant predictor of IVFPGD cycle success (as regular ART cycles)
• Optimal oocyte: 15, younger: 10 ~ 15, older: 15 ~ 20
• Adequately stimulation & wish to conceive with their
own eggs(even 1~7#) OR & PGD may be continued
• Young, poor response to COH  No risk for OHSS 
[Gn] dosage may be safely ↑ to the Max dosage
• Patients with fragile X, Myotonic Dystrophy, balanced
translocation: ↓ ovarian response to COH; Not
affect outcome of ETs
Elective Single Embryo Transfer & PGD
Elective Single Embryo Transfer (e-SET)
• To prevent Multiple pregnancies
– Significantly ↓ twin pregnancy rates
– Significantly ↓ the likelihood of live birth
– ↑ Number of eSET attempts (fresh or frozen)  a
cumulative LBR similar to that of DET (double-ET)
 Vitrified cryo-thawed biopsied embryos + PGD  May
reach a survival rate & implantation rate comparable
with embryos with no biopsy
 e-SET should be offered to young women undergoing
PGD or PGS, (esp. when top-quality embryos available)
Clinical Expertise in IVF-PGD Treatments
• Affect embryonic survival and development:
– Expertise of the embryologists in performing
biopsies for PGD
– Type of procedure used to breach the zona
pellucida
– Type (polar bodies, blastomere, and/or
trophectoderm) & number of cells biopsied
• Rate for misdiagnosis at experienced PGD
laboratories: <1.0% (0.3 ~ 0.6%)
• Centers for Disease Control and Prevention (2006):
– 5/426 U.S. centers performed >50 cycles with PGD
– Among them >10 cycles specifically for the purpose of
prevention of genetic disorders
– 3 in New York, 1 in Colorado, 1 in Chicago, Illinois
• ESHRE & PGD International Society (PGDIS)
– Minimal requirement for ART and PGD centers
– Collaboration (Preferred ovarian stimulation protocol,
Optimal location for the patient's monitoring, Oocyte
retrieval, embryology work including embryo biopsy)
– Reliable communication system for reporting PGD results
Suggestion for practice PGD
• ART centers should: Evaluate their experience &
outcome of IVF for PGD  Decided whether to offer
• Monitor the stimulation locally
• Oocyte retrieval, embryology, biopsy, PGD testing
may be performed at a more experienced center
(or embryo biopsy by an experienced local or traveling
embryologist, & the PGD performed at another location)
• Following the guidelines published by ESHRE and/or
PGDIS
Special PGD Challenges for Clinical
Management
Nondisclosure PGD
• Potential carriers of Late-onset autosomal dominant
diseases:
– Ex.: Huntington disease (HD) & amyotrophic
lateral sclerosis (ALS)
– Elect not to be tested
– Wish to assure that their children will not carry
the disease
– Have the right not to know their genetic status
Revised nondisclosure PGD protocol
Tur-Kaspa and Najeemuddin
(1) Direct mutation testing  maintain nondisclosure
(all medical & administrative staff in direct contact with the
couple will not be aware of the genetic status of the patient)
(2) General PGS  Risk of nonrelated fetal
chromosomal abnormalities (thus the issue of
payment for "unperformed PGD" will be avoided)
(3) Aneuploidy or embryo development may cause to
have no embryos for transfer, regardless of the
patients' genetic status, performing sham transfers
will not be needed
4) Embryo cryopreservation will be performed when
possible
5) Because direct mutation testing will be performed,
no unaffected embryos will be discarded
6) Avoid multiple pregnancies, the couple will decide
in advance whether they wish for one or two (if
possible) blastocysts to be transferred
PGD for HLA Typing
• “Savior siblings”: International controversy
• Matched Hematopoietic Stem Cell Transplantation:
– Donate cord blood or bone marrow
– Nonmalignant disorders
• Genetic diseases affecting the hematopoietic
and/or the immune system: (Thalassemia, Fanconi
anemia, Wiskott-Aldrich syndrome, sickle-cell disease)
• Acquired diseases like aplastic anemia
– Malignant diseases like leukemia (↓ Posttransplant morbidity/mortality rates)
Clinical guidelines to offer PGD for HLA typing
To parents of a sick child
• Tur-Kaspa and Najeemuddin
1. When a related matched donor is not available
within weeks of the diagnosis (even for diseases with
a good prognosis)
2. When HSCT is not urgent and clinically can be
postponed by at least 9 to 12 months
3. If not available locally or nationally  collaboration
with another center
(IHR & RGI: Established clinical collaborations with
>100 different centers worldwide)
Summary
• It’s a unique opportunity for parents to act
independently to save their sick child with HSCT
• Clinical guidelines Will improve the care of children
in need of matched HSCT
• Once future advances lead to improved outcomes of
unrelated transplants, this rationale should be
revised
The Future of PGD
• PGD may now be offered (with or without disclosure):
– All known single-gene disorders
– Chromosomal rearrangement
– HLA-matched siblings
– Cancer predisposition genes
– Late-onset disorders
– Monogenic disorders
– Translocations together with aneuploidy
– Couple who carry a genetic disorder
• PGS for advanced maternal age, repeated pregnancy
loss, repeated IVF failures, severe male infertility 
on the rise until 2007
• Large-scale national IVF-PGD program  As a novel
preventive medical strategy for diseases like CF
 may have a profound potential in modern healthcare systems
• PGD: should be encouraged to become an integral
part of any health-care system and should be
covered by medical insurances
• Biopsy for PGD:
– May affect implantation potential
– In general seems to be safe, except when two cells
are removed on day 3
– Children born after PGD have similar outcomes 
Regular IVF/ICSI infants
• Optimization/Individualization of ovarian stimulation
• Collaborations with experienced centers  Allow
PGD with any number of oocytes/embryos available
• SET:
– May be offered to young patients after PGD or
PGS for 24 chromosomes
– With good quality blastocysts to avoid a multiple
pregnancy
– Better clinical management of IVF-PGD treatments
will improve its outcome
Thank you for listening