Presentation by Maria Traversa Senior Scientist, Genea Limited Presented at the World Congress on Human Reproduction 2011, Melbourne

1. CGH in the PGD program –
a new tool for improved IVF outcomes?
a new tool for improved IVF outcomes?
Maria Traversa
Maria Traversa
Senior Scientist, Genea Limited
Presented at the World Congress on Human Reproduction 2011, Melbourne
Presented at the World Congress on Human Reproduction 2011 Melbourne
Dec 2011 1

2. PGD chromosome techniques
Analysis of an embryo’s chromosomes before it is transferred
back into the uterus
b k i t th t
Three main techniques:
> FISH ‐ for small chromosome regions
FISH for small chromosome regions
> PCR ‐ for chromosome regions (and genes)
> CGH complete set of all 24 chromosomes
CGH ‐ l t t f ll 24 h
Dec 2011 2 © 2011 Genea Limited | genea.com.au

3. Current biopsy techniques
> Polar body biopsy
‐ maternal markers only
> Day 3 biopsy
Day 3 biopsy
‐ remove 1 or 2 cells
> Blastocyst biopsy
l b
‐ more labs now implementing
Dec 2011 3
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4. Blastocyst biopsy – our approach since 2004
> Why wait till blastocyst stage?
– blastulation‐ best developing embryos identified
> fe er embr os need to be anal sed
fewer embryos need to be analysed
– fewer resources needed
> more cells can be taken = more DNA
– improved analysis with less error rate
> reduced impact on embryo?
Dec 2011 4 © 2011 Genea Limited | genea.com.au

5. Summary – blastocyst biopsy
> Outcomes are better than cleavage stage biopsy
– Improved embryo viability?
Improved embryo viability?
> The number of cycles achieving transfer is lower but outcome per IVF
cycle started is similar
l d i i il
– Fewer futile transfers
> Clinical pregnancy rate per embryo transferred is higher
– sET is possible
> Reduced costs for PGD
– Number of embryos analysed is reduced
y y
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6. The problems with FISH:
> Accuracy/Error rates
y/
‐Cell loss
‐Signal overlap/splitting
‐Variable cell fixation (residual cytoplasm)
‐Hybridization efficiency/times (multiple)
‐Cell overlap (blastocyst biopsy)
Cell overlap (blastocyst biopsy)
> Limit on fluorophors available‐ 5
‐up to 12 chromosomes‐ 3 hybridisations!
p y
> Diploid‐aneuploid mosaicism (blastocyst biopsy)
‐small proportion of aberrant cells in sample
Dec 2011 6 © 2011 Genea Limited | genea.com.au

7. PGD trial outcomes:
> A randomised clinical trial of blastocyst biopsy to ascertain whether chromosome
screening improves IVF outcomes
screening improves IVF outcomes
‐ terminated early when we were not able to show any advantage for PGS
Human Reproduction Vol.23, No.7 pp. 1476–1478, 2008
Conclusion: We needed a more accurate and extensive test for chromosomal error
Dec 2011 7 © 2011 Genea Limited | genea.com.au

8. Comparative genetic diagnosis – CGH
• CGH is a process that allows us to look at all 24
chromosomes in an embryo
• Female = 46, XX
Female 46, XX
• Male = 46, XY
• Process takes several days to achieve results therefore all
embryos need to be vitrified
b d t b it ifi d
• Cryo embryo transfer in subsequent cycle
Dec 2011 8 © 2011 Genea Limited | genea.com.au

9. Array CGH
> 60 000 points on chromosomes
measured
> y y p
8 sub arrays = 8 embryos per slide
> embryo karyotype
Dec 2011 9 © 2011 Genea Limited | genea.com.au

10. CGH – Analysis
Log ratio
Log ratio
Moving average
Dec 2011 10 © 2011 Genea Limited | genea.com.au

11. Aneuploid chromosomes
25.0
20.0
neuploidy rate (%)
15.0
IVF miscarrage samples
10.0
PGD Embryos
PGD Embryos
An
5 panel = 35%
5.0 9 panel = 72%
12 panel = 78%
0.0
25% of abnormal
10
11
12
13
14
15
16
17
18
19
20
21
22
1
2
3
4
5
6
7
8
9
X/Y
embryos still
Chromosome missed
Dec 2011 11 © 2011 Genea Limited | genea.com.au

12. CGH patients
Patient data
Couples with biopsy cycles 105
with transfer (so far) 56
Average maternal
Average maternal age 38.1
38 1
No. previous IVF treatments <38yrs 2.2
>38yrs 2.1
embryos biopsied 404 (av. 5.7 for <38yrs and 3.9 >38yrs)
aneuploid embryos detected 181 (49%)
y py
Cycles with no biopsy 58%
successful analyses ~94 %
Dec 2011 12 © 2011 Genea Limited | genea.com.au

13. CGH outcomes
Pregnancy outcomes
embryos transferred 60
implantation rate (# implantations) 52% (31)
<38yrs 61% (23/38)
>38yrs 41% (8/22)
Clinical pregnancy rate (FH)/oocyte retrieval with transfer
Clinical pregnancy rate (FH)/oocyte retrieval with transfer 67% (28/42)
67% (28/42)
<38yrs 81% (21/26)
>38yrs 44% (7/16)
Dec 2011 13 © 2011 Genea Limited | genea.com.au

14. CGH results – Effects of aneuploidy with age
Dec 2011 14 © 2011 Genea Limited | genea.com.au

15. CGH results – Comparison to age matched IVF cryo cycles
Dec 2011 15 © 2011 Genea Limited | genea.com.au

16. CGH results: aCGH vs FISH
Dec 2011 16 © 2011 Genea Limited | genea.com.au

17. CGH – Conclusion
> Whilst this is a retrospective review of outcomes,
Whilst this is a retrospective review of outcomes,
when compared to general IVF patients, applying PGS
with aCGH in poor prognosis patients shows an
with aCGH in poor prognosis patients shows an
improved implantation rate.
‐ Several randomised trials currently underway
> Other factors, such as uterine receptivity, may also be
contributing to the improved outcomes when
ib i h i d h
applying aCGH to this cohort of patients
Dec 2011 17 © 2011 Genea Limited | genea.com.au

18. Thank you
Thank you
Dec 2011 18 © 2011 Genea Limited | genea.com.au