ABSTRACT
Preservation at low temperatures is a practice that has found several applications
in medicine and biotechnology. Several types of cells and tissues can be stored virtually
indefinitely in liquid nitrogen (–196°C) and returned to physiological temperatures.
However, phenomena occurring during cooling and warming may affect the structure and
function of the stored material. To some extent, the use of substances with special
protective properties, referred to as cryoprotective agents, may avoid this effect,
but normally a fraction of the cryopreserved material suffers a partial or total loss
of viability. In the context of human in vitro fertilization (IVF), for decades cryopreservation
has been used to store different materials of reproductive function, mainly embryos
at various developmental stages and spermatozoa. In recent times, the realm of cryopreservation
has been expanded to also include fully grown unfertilized oocytes. The storage of
oocytes offers obvious advantages, eluding legal and ethical problems that afflict,
and sometimes make inapplicable, embryo cryopreservation. Until recently, technical
and applicative advances of oocyte cryopreservation were inhibited by the preconception
that the unique nature of this cell was an insurmountable obstacle to safe and efficient
preservation at low-temperature storage. In fact, through the two alternative methodological
approaches of controlled rate slow cooling and vitrification, oocyte cryopreservation
has been developed both technically and clinically to a stage that is beginning to
challenge the supremacy of embryo freezing as the preferred form of fertility preservation
for the treatment of infertile couples. Although several questions remain to be answered
as to whether oocyte cryopreservation can ensure adequate standards of efficacy and
safety, there appears to be little doubt that in the near future oocyte cryopreservation
will be recognized as an established form of IVF treatment.
KEYWORDS
Oocytes - cryopreservation - IVF - clinical efficacy - safety of cryopreservation
REFERENCES
- 1
Paynter S J.
A rational approach to oocyte cryopreservation.
Reprod Biomed Online.
2005;
10(5)
578-586
- 2
Lassalle B, Testart J, Renard J P.
Human embryo features that influence the success of cryopreservation with the use
of 1,2 propanediol.
Fertil Steril.
1985;
44(5)
645-651
- 3
Borini A, Bonu M A, Coticchio G, Bianchi V, Cattoli M, Flamigni C.
Pregnancies and births after oocyte cryopreservation.
Fertil Steril.
2004;
82(3)
601-605
- 4
Queenan Jr J T, Veeck L L, Toner J P, Oehninger S, Muasher S J.
Cryopreservation of all prezygotes in patients at risk of severe hyperstimulation
does not eliminate the syndrome, but the chances of pregnancy are excellent with subsequent
frozen-thaw transfers.
Hum Reprod.
1997;
12(7)
1573-1576
- 5
Jackowski S, Leibo S P, Maxur P.
Glycerol permeabilities of fertilized and infertilized mouse ova.
J Exp Zool.
1980;
212
329-341
- 6
Ducibella T.
Biochemical and cellular insights into the temporal window of normal fertilization.
Theriogenology.
1998;
49(1)
53-65
- 7
Fissore R A, Kurokawa M, Knott J, Zhang M, Smyth J.
Mechanisms underlying oocyte activation and postovulatory ageing.
Reproduction.
2002;
124(6)
745-754
- 8
Nottola S A, Macchiarelli G, Coticchio G et al..
Ultrastructure of human mature oocytes after slow cooling cryopreservation using different
sucrose concentrations.
Hum Reprod.
2007;
22(4)
1123-1133
- 9
Ghetler Y, Skutelsky E, Ben Nun I, Ben Dor L, Amihai D, Shalgi R.
Human oocyte cryopreservation and the fate of cortical granules.
Fertil Steril.
2006;
86(1)
210-216
- 10
Ozil J P, Huneau D.
Activation of rabbit oocytes: the impact of the Ca2+ signal regime on development.
Development.
2001;
128(6)
917-928
- 11
Jones A, Van Blerkom J, Davis P, Toledo A A.
Cryopreservation of metaphase II human oocytes effects mitochondrial membrane potential:
implications for developmental competence.
Hum Reprod.
2004;
19(8)
1861-1866
- 12
Larman M G, Sheehan C B, Gardner D K.
Calcium-free vitrification reduces cryoprotectant-induced zona pellucida hardening
and increases fertilization rates in mouse oocytes.
Reproduction.
2006;
131(1)
53-61
- 13
Battaglia D E, Goodwin P, Klein N A, Soules M R.
Influence of maternal age on meiotic spindle assembly in oocytes from naturally cycling
women.
Hum Reprod.
1996;
11(10)
2217-2222
- 14
Gook D A, Osborn S M, Johnston W I.
Cryopreservation of mouse and human oocytes using 1,2-propanediol and the configuration
of the meiotic spindle.
Hum Reprod.
1993;
8(7)
1101-1109
- 15
Gook D A, Osborn S M, Bourne H, Johnson W I.
Fertilization of human oocytes following cryopreservation; normal karyotypes and absence
of stray chromosomes.
Hum Reprod.
1994;
9(4)
684-691
- 16
Mullen S F, Agca Y, Broermann D C, Jenkins C L, Johnson C A, Critser J K.
The effect of osmotic stress on the metaphase II spindle of human oocytes, and the
relevance to cryopreservation.
Hum Reprod.
2004;
19(5)
1148-1154
- 17
Joly C, Bchini O, Boulekbache H, Testart J, Maro B.
Effects of 1,2-propanediol on the cytoskeletal organization of the mouse oocyte.
Hum Reprod.
1992;
7(3)
374-378
- 18
Johnson M H, Pickering S J.
The effect of dimethylsulphoxide on the microtubular system of the mouse oocyte.
Development.
1987;
100(2)
313-324
- 19
Coticchio G, De Santis L, Rossi G et al..
Sucrose concentration influences the rate of human oocytes with normal spindle and
chromosome configurations after slow-cooling cryopreservation.
Hum Reprod.
2006;
21(7)
1771-1776
- 20
Cobo A, Rubio C, Gerli S, Ruiz A, Pellicer A, Remohí J.
Use of fluorescence in situ hybridization to assess the chromosomal status of embryos
obtained from cryopreserved oocytes.
Fertil Steril.
2001;
75(2)
354-360
- 21
Stachecki J J, Munné S, Cohen J.
Spindle organization after cryopreservation of mouse, human, and bovine oocytes.
Reprod Biomed Online.
2004;
8(6)
664-672
- 22
Cobo A, Pérez S, De los Santos M J, Zulategui J, Domingo J, Remohí J.
Effect of different cryopreservation protocols on the metaphase II spindle in human
oocytes.
Reprod Biomed Online.
2008;
17(3)
350-359
- 23
Coticchio G, Sciajno R, Hutt K J et al..
Comparative analysis of the metaphase II spindle of human oocytes through polarized
light and high performance confocal microscopy.
Fertil Steril.
2009;
, February 23. (Epub ahead of print)
- 24
Borini A, Sciajno R, Bianchi V, Sereni E, Flamigni C, Coticchio G.
Clinical outcome of oocyte cryopreservation after slow cooling with a protocol utilizing
a high sucrose concentration.
Hum Reprod.
2006;
21(2)
512-517
- 25
Levi Setti P E, Albani E, Novara P V, Cesana A, Morreale G.
Cryopreservation of supernumerary oocytes in IVF/ICSI cycles.
Hum Reprod.
2006;
21(2)
370-375
- 26
De Santis L, Cino I, Rabellotti E et al..
Oocyte cryopreservation: clinical outcome of slow-cooling protocols differing in sucrose
concentration.
Reprod Biomed Online.
2007;
14(1)
57-63
- 27
Parmegiani L, Cognigni G E, Bernardi S et al..
Freezing within 2 h from oocyte retrieval increases the efficiency of human oocyte
cryopreservation when using a slow freezing/rapid thawing protocol with high sucrose
concentration.
Hum Reprod.
2008;
23(8)
1771-1777
- 28
Chen S U, Lien Y R, Chen H F, Chang L J, Tsai Y Y, Yang Y S.
Observational clinical follow-up of oocyte cryopreservation using a slow-freezing
method with 1,2-propanediol plus sucrose followed by ICSI.
Hum Reprod.
2005;
20(7)
1975-1980
- 29
Boldt J, Tidswell N, Sayers A, Kilani R, Cline D.
Human oocyte cryopreservation: 5-year experience with a sodium-depleted slow freezing
method.
Reprod Biomed Online.
2006;
13(1)
96-100
- 30
Lucena E, Bernal D P, Lucena C, Rojas A, Moran A, Lucena A.
Successful ongoing pregnancies after vitrification of oocytes.
Fertil Steril.
2006;
85(1)
108-111
- 31
Gook D A, Edgar D H.
Cryopreservation of the human female gamete: current and future issues.
Hum Reprod.
1999;
14(12)
2938-2940
- 32
Edgar D H, Gook D A.
How should the clinical efficiency of oocyte cryopreservation be measured?.
Reprod Biomed Online.
2007;
14(4)
430-435
- 33
Edgar D H, Bourne H, Speirs A L, McBain J C.
A quantitative analysis of the impact of cryopreservation on the implantation potential
of human early cleavage stage embryos.
Hum Reprod.
2000;
15(1)
175-179
- 34
Fabbri R, Porcu E, Marsella T, Rocchetta G, Venturoli S, Flamigni C.
Human oocyte cryopreservation: new perspectives regarding oocyte survival.
Hum Reprod.
2001;
16(3)
411-416
- 35
Bianchi V, Coticchio G, Distratis V, Di Giusto N, Flamigni C, Borini A.
Differential sucrose concentration during dehydration (0.2 mol/l) and rehydration
(0.3 mol/l) increases the implantation rate of frozen human oocytes.
Reprod Biomed Online.
2007;
14(1)
64-71
- 36
Edgar D H, Archer J, McBain J, Bourne H.
Embryonic factors affecting outcome from single cryopreserved embryo transfer.
Reprod Biomed Online.
2007;
14(6)
718-723
- 37
Land J A, Evers J L.
What is the most relevant standard of success in assisted reproduction? Defining outcome
in ART: a Gordian knot of safety, efficacy and quality.
Hum Reprod.
2004;
19(5)
1046-1048
- 38
Min J K, Breheny S A, MacLachlan V, Healy D L.
What is the most relevant standard of success in assisted reproduction? The singleton,
term gestation, live birth rate per cycle initiated: the BESST endpoint for assisted
reproduction.
Hum Reprod.
2004;
19(1)
3-7
- 39
Pinborg A, Loft A, Ziebe S, Nyboe Andersen A.
What is the most relevant standard of success in assisted reproduction? Is there a
single ‘parameter of excellence’?.
Hum Reprod.
2004;
19(5)
1052-1054
- 40
Nyboe Andersen A, Gianaroli L, Nygren K G. European IVF-monitoring programme .
Assisted reproductive technology in Europe, 2000. Results generated from European
registers by ESHRE.
Hum Reprod.
2004;
19(3)
490-503
- 41
Tiitinen A, Hydén-Granskog C, Gissler M.
What is the most relevant standard of success in assisted reproduction?: The value
of cryopreservation on cumulative pregnancy rates per single oocyte retrieval should
not be forgotten.
Hum Reprod.
2004;
19(11)
2439-2441
- 42
Germond M, Urner F, Chanson A, Primi M P, Wirthner D, Senn A.
What is the most relevant standard of success in assisted reproduction?: The cumulated
singleton/twin delivery rates per oocyte pick-up: the CUSIDERA and CUTWIDERA.
Hum Reprod.
2004;
19(11)
2442-2444
- 43
Schröder A K, Banz C, Katalinic A et al..
Counselling on cryopreservation of pronucleated oocytes.
Reprod Biomed Online.
2003;
6(1)
69-74
- 44
Tiitinen A, Halttunen M, Härkki P, Vuoristo P, Hyden-Granskog C.
Elective single embryo transfer: the value of cryopreservation.
Hum Reprod.
2001;
16(6)
1140-1144
- 45
Borini A, Bianchi V, Bonu M A et al..
Evidence-based clinical outcome of oocyte slow cooling.
Reprod Biomed Online.
2007;
15(2)
175-181
- 46
Porcu E, Fabbri R, Damiano G et al..
Clinical experience and applications of oocyte cryopreservation.
Mol Cell Endocrinol.
2000;
169(1-2)
33-37
- 47
Parmegiani L, Cognigni G E, Bernardi S et al..
Freezing within 2 h from oocyte retrieval increases the efficiency of human oocyte
cryopreservation when using a slow freezing/rapid thawing protocol with high sucrose
concentration.
Hum Reprod.
2008;
, In press
- 48
Borini A, Cattoli M, Mazzone S et al..
Survey of 105 babies born after slow-cooling oocyte cryopreservation.
Fertil Steril.
2007;
88(suppl)
S13-S14
- 49
Tur-Kaspa I, Gal M, Horwitz A.
Genetics and health of children born from cryopreserved oocytes.
Fertil Steril.
2007;
88
037
- 50
Maher B.
Little consensus on egg freezing.
Nature.
2007;
449(7165)
958
- 51
Noyes N, Porcu E, Borini A.
Over 900 oocyte cryopreservation babies born with no apparent increase in congenital
abnormalities.
Reprod Biomed Online.
2009;
18(6)
769-776
Andrea BoriniM.D.
Tecnobios Procreazione
Via Dante 15, 40125 Bologna, Italy
Email: borini@tecnobiosprocreazione.it
