McGill University
Hananel Holzer, MD
McGill University
Health Centre
Medical Director, MUHC Reproductive Center
McGill University Health Center
Director, REI Division, Dept. of Obstetrics & Gynecology
McGill University
Fertility preservation
No male partner:
Oocyte cryopreservation
1st live birth 1986 (Chen et al)
But:
• oocytes vulnerable to freezing process
• intracellular ice formation
• membrane rupture, abnormal cortical
granule reaction, zona hardening,
meiotic spindle and cytoskeleton
damage
• 1986-1997: 5 live births
No male partner:
Oocyte cryopreservation
• Using PROH/sucrose slow freezing
protocol and introduction of ICSI
improved pregnancy rates (Porcu et al 1997)
• Reported survival rates for mature
oocytes (collected from stimulated
ovaries) are 50-70%
Oocyte vitrification
• Cryoprotectants in high concentration
used to induce glasslike state, cell then
rapidly frozen avoiding formation of
intracellular ice
• Kuleshova et al, 1999: survival rate
65%, PR/ET 21%
• Yoon et al, 2003: survival rate 69%,
implantation rate 6.4%, PR/ET 21.4%
• Katayama et al, 2003: survival rate 94%,
PR/ET 33%
Oocyte vitrification
• 165 live births (Chian et al ASRM 2007: McGill
Reproductive Center in Canada, Instituto Mexicano de
Infertilidad in Mexico and CECOLFES in Colombia)
• A few thousand babies
• Vitrification is emerging to be a better
technique.
Embryo or oocyte cryopreservation
after ovarian stimulation
• Pregnancies reported are result of fertilization of
frozen/thawed oocytes collected after ovarian
stimulation
• However:
− time interval needed for ovarian stimulation 2-6
weeks.
− Starting during menstruation
− Time may not be available for cancer patients
− Recent studies: stimulation luteal phase. (Von Wolff
2009, Sonmezer 2011)
− ovarian stimulation associated with high estrogen
levels which may not be safe in cases of hormone
sensitive tumors such as breast cancer
− Estrogens may have an indirect mitogenic effect on
receptor negative cancers. (Gupta PB 2006)
Embryo or oocyte cryopreservation
after ovarian stimulation
Aromatase inhibitor + FSH:
• letrozole started 2 days before FSH
administration, then given concomitantly,
no increased risk of relapse (Oktay 2005, 2007, Azim
2008)
• Lower estradiol levels
• does not totally avoid stimulation
• Early follicular start of treatment.
• More studies are needed
Collection of immature oocytes
from unstimulated ovaries
• Pincus, J Exp Med 1935; Edwards,
Nature, 1965,1969.
• Cha et al,1991: Immature oocyte
laparotomy for oocyte donation
• Trounson et al, 1994: IVM: vaginal
collection of immature oocytes, for PCO
related infertility
Mature oocytes at oocyte collection
in IVM cycles
8mm
12mm
14mm
Vitrification of IVM oocytes?
• Could oocytes collected from
unstimulated ovaries, matured in vitro,
then vitrified survive thawing and be
fertilized?
• Could transfer of these embryos result in
a viable pregnancy?
Vitrification of IVM oocytes
No. of patients
Mean age
No. of mature oocytes retrieved
No. of immature oocytes retrieved
Mean oocyte maturation rate (%)
No. of oocytes vitrified and thawed
20
30.7 ±3.7
7
295
67.9+4.1
215
No. of oocytes survived (mean % + SEM )
148 (67.5 + 5.8)
No. of oocytes fertilized (mean % + SEM)
96 (64.2 + 4.5)
No. of embryos transferred (median; range)
No. of implantations (mean % + SEM)
No. of clinical pregnancies (%)
No. of live births (%)
64 (3.2; range 1 - 6)
5 (10.3+5.7)
4 (20.0)
4 (20)
Holzer et al ESHRE 2007
Conclusions
Vitrification of in-vitro matured oocytes
collected from unstimulated ovaries
followed by later thawing and fertilization
can result in successful pregnancies and
live births
Conclusions
• Preliminary results
• 20 patients, all with PCO
• 20% pregnancy rate (vs. 35% in “Fresh
IVM” )
• Lower implantation rate (10.8% vs.
14.4%)
• Learning curve?
Conclusions
• Collection of immature oocytes from unstimulated
ovaries followed by IVM and vitrification of mature
oocytes could be offered to patients with hormonesensitive disease and/or when there is not enough
time to stimulate ovaries
– no risk of aggravating disease
– no theoretic risk of re-instituting metastatic
malignant disease
– does not require same amount of time as that
needed for ovarian stimulation, no need to wait
for next cycle
When ovarian tissue is being
harvested
•
Additional strategy of fertility
preservation combines ovarian tissue
cryobanking with retrieval of immature
oocytes from excised ovarian tissue,
followed by in vitro maturation (IVM)
and vitrification (Huang, Tulandi, Holzer, Tan, Chian
Fertil Steril 2007)
•
When surgery performed to remove
ovarian tumor or for other therapeutic
indications
Fertility preservation in
prepubertal children
• Childhood and adolescence period of
emotional and psychological instability;
issues of sexuality, including fertility, are of
particular importance
• Depletion of primordial oocytes after
gonadotoxic treatment proportional to size
of oocyte pool
• Younger patients have more oocytes; thus
gonadal damage could seem to be less
severe than in older patients
Fertility preservation in
prepubertal children
• Global incidence of acute ovarian failure
in childhood cancer survivors ranges
from 6.3 to 12% (Bakker 2004)
• In Childhood Cancer Survivor Study ;the
relative risk for survivors of ever being
pregnant was 0.81 (Green DM 2009)
• Very few treatments benefit younger
patients at risk of infertility after
treatment
Fertility preservation in prepubertal
children; Ovarian tissue cryobanking
• Primary method of fertility preservation for prepubertal
girls
• One ovary removed from 47 patients aged 0.1-14 y
(median: 5)
• Ovarian tissue fragments frozen
• strong inverse correlation found between age and
follicular density
• none of the cases had visible ovarian tumour
components (Poirot 2007)
• 58 patients 0.8-15.8 years, underwent ovarian
tissue cryopreservation.
• 1 case of ovarian lymphoma infiltration (Jadoul 2010)
Fertility preservation in prepubertal
children: Combined approach
• Unilateral oophorectomy: 19 patients
aged 5-20 years (median 15 yrs.)
• Antral follicles aspirated, average no. of
oocytes: 9 (0-37)
− GV oocytes – IVM
− mature oocytes – frozen
• Ovarian tissue – cryopreserved in
fragments
(Revel 2008)
Fertility preservation in prepubertal
children: Ovarian tissue cryobanking
• Reimplantation of ovaries cryopreserved before
puberty not yet performed in either nonpubertal
or pubertal recipients
• Animal models: puberty and fertility restored
(Sauvat 2008)
• Removal of entire ovary, although strongly
advocated by some, may not be recommended
for pediatric patients in whom fertility outcome
is often uncertain.
• How much? Based on the risk of the planned
treatment and the ovarian volume.
Fertility preservation in prepubertal children
• Fertility preservation should now be
considered in children facing cancer
treatment with high risk of gonadal
toxicity, including high-dose
chemotherapy and bilateral irradiation of
gonads at toxic doses
• Multidisciplinary team