1. Embryo development of fresh
“versus” vitrified metaphase II
oocytes after ICSI: a prospective
randomized sibling-oocyte study
Human Reproduction Vol.25 No.1 pp.66-73, 2010
2009/12/24
Ian Huang

2. March 2004 to May 2009
• Italian Law No. 40 regulates ART
1. no more than 3 oocytes could be inseminated per
cycle.
2. all obtained embryos had to be transferred.
3. embryo cryopreservation and gamete donation
were forbidden.
• As a results, oocyte selection and oocyte
preservation have been a routine practice in Italian
IVF centers.

3. Recent edict of Italian Constitutional
Court (151/2009)
• 1. embryo freezing is constitutional, if
determined by the health of the patient.
• 2. the numbers of oocytes to be inseminated
is now chosen by the physician.
• The population of this study is from
2008/9/2 to 2009/3/10

4. Aim
• To compare the in vitro performance of
fresh and vitrified oocytes post-ICSI
procedure.
• Measure fertilization, PN morphology,
embryo development and embryo
morphology of fresh and vitrified sibling
oocytes.

5. Target population
• 1. < 42 yrs old
• 2. more than 6 normal MII oocytes
• 3. MESA/TESE or motile sperm count <
0.5x10^6/ml after preparation are excluded.
• 4. PB biopsy is excluded.

6. Methods
• GnRH agonist long protocol and GnRH-
antagonist protocol for stimulation.
• Oocyte collection at 35 h post-hCG.
• Denudation at 37 to 40 h post-hCG.
• Oocytes with dark cytoplasm, centrally
located granular area, giant with vacuoles,
large polar body were excluded.

7. • radom number assign for normal MII oocyte by
computer-generated random list.
• 1, 2, 3 for fresh ICSI
• others for vitrification(warmed ICSI). (4, 5, 6,
….so on)
• fresh ICSI:
maximum of 3 oocyte were inseminated, and all
obtained embryos are transferred at 44-48 h post
ICSI.
• warmed ICSI:
warmed at 36-40 h post-hCG in nature cycle,
surviving oocytes were cultured at 37℃(6%CO2,
5%O2) for 2 h before ICSI.

8. Results

11. Discussion
• According to the results, embryo development up to Day 2
is not affected by vitrification procedure.
• Oocyte survival rate was higher than 95%.
• The number of oocytes degenerated during warming
procedure was negligible and did not affect the overall
fertilization rate.
• Although some, non-significant, differences in pronuclear
morphology were observed, embryo quality was similar in
the two groups.
• The percentage of top quality embryos per fertilized
oocyte was about 52% in fresh and vitrified group of
oocytes.

12. Discussion
• Four ongoing pregnancies (30.7%) were obtained
in women aged > 38 years. It cannot be excluded
that endometrium receptivity may also be involved
in successful implantation of embryos derived
from vitrified oocytes.
• By transferring embryos in a natural unstimulated
cycle, synchronization of embryo and endometrial
development can be, in fact, probably better
obtained.

13. Discussion
• This results indicate that oocyte vitrification
procedure followed by ICSI is not inferior to fresh
insemination procedure, with regard to
fertilization and embryo developmental rates.
• Moreover, ongoing clinical pregnancy is
compatible with this procedure, even with a
restricted number of oocytes available for
insemination.
• The promising clinical results obtained, in a
population of infertile patients, need to be
confirmed on a larger scale.

14. Thank you !!