• Borut Kovačič Oddelek za reproduktivno medicino in ginekološko endokrinologijo Služba za ginekologijo in perinatologijo Splošna bolnišnica Ljubljanska 5 2000 Maribor
  • Veljko Vlaisavljević Oddelek za reproduktivno medicino in ginekološko endokrinologijo Služba za ginekologijo in perinatologijo Splošna bolnišnica Ljubljanska 5 2000 Maribor
Keywords: oocyte, meiosis, in vitro maturation, fertilization, clinical use


Background. Among oocytes obtained during aspiration of preovulatory ovarian follicles in hormonally stimulated cycles, we ascertained the percentage of immature oocytes with the nucleus in the metaphase (M I oocytes) or even in the prophase (GV oocytes) of the first meiotic division and their capacity to mature in vitro in a simple medium without hormonal supplements.

Methods. In 818 women, stimulated by gonadotropin releasing hormone agonist (GnRHa) and gonadotropins, aspiration of preovulatory size follicles yielded 4972 oocytes. From these we denuded cells of cumulus oophorus and corona, meiotic maturity was evaluated under a microscope. Cells in the metaphase of the second meiotic division (M II oocytes) and those maturing after 5 hours were used clinically in the intracytoplasmic sperm injection (ICSI) procedure. Immature cells were left in the simple medium. The degree of their nuclear maturity was evaluated after one and after two days of culture. In vitro maturation was clinically used also in 14 cycles with no mature oocytes.

Results. Among 4731 oocytes with denuded corona and cumulus, 4199 (88.8%) were mature M II oocytes, 295 (6.2%) immature M I oocytes and 237 (5%) immature GV oocytes. Under in vitro conditions, 68.7% (90/131) GV oocytes attained maturity. Among M I oocytes, 63.6% (136/214) cells matured already after 5 hours and 26.6% (57/214) until the next day. In all 14 women with only immature oocytes, the embryos for embryotransfer were obtained after in vitro maturation and ICSI procedure. The result was four pregnancies and two deliveries.

Conclusions. Immature oocytes, obtained in hormonally stimulated cycles, may become clinically applicable if left to mature in vitro in a simple medium without supplementation of growth factors and hormones.


Download data is not yet available.


Schultz R. Control mechanisms regulating meiotic maturation of mammalian oocytes. In: Wolf Don P ed. In vitro fertilization and embryo transfer. New York: Plenum Press, 1988: 349–58.

Edwards RG. Maturation in vitro of human ovarian oocytes. Lancet 1965; 2: 926–6.

Veeck LL, Wortham JE, Witmyer J, Sandow BA, Acosta AA, Garcia JE et al. Maturation and fertilization of morphologically immature human oocytes in a program of in vitro fertilization. Fertil Steril 1983; 39: 594–602.

Cha KY, Koo JJ, Ko JJ et al. Pregnancy after in vitro fertilization of human follicular oocytes collected from nonstimulated cycles, their culture in vitro and their transfer in a donor oocyte program. Fertil Steril 1991; 55: 109–13.

Trounson A, Wood C, Kausche A. In vitro maturation and the fertilization and developmental competence of oocytes recovered from untreated polycystic ovarian patients. Fertil Steril 1994; 62: 353–62.

Barnes FL, Crombie A, Gardner DK et al. Blastocyst development and birth after in-vitro maturation of human primary oocytes, intracytoplasmic sperm injection and assisted hatching. Hum Reprod 1995; 10: 3243–7.

Russell JB, Knezevich BA, Fabian KF et al. Unstimulated immature oocyte retrieval: early versus midfollicular endometrial priming. Fertil Steril 1997; 67: 616–20.

Nagy ZP, Cecile J, Liu J, Loccufier A, Devroey P, Van Steirteghem A. Pregnancy and birth after intracytoplasmic sperm injection of in vitro matured germinal-vesicle stage oocytes: case report. Fertil Steril 1996; 65: 1047–50.

Edirisinghe WR, Junk SM, Matson PL, Yovich JL. Birth from cryopreserved embryos following in-vitro maturation of oocytes and intracytoplasmic sperm injection. Hum Reprod 1997; 12: 1056–8.

Liu J, Katz E, Garcia JE et al. Successful in vitro maturation of human oocytes not exposed to human chorionic gonadotropin during ovulation induction, resulting in pregnancy. Fertil Steril 1997; 67: 566–8.

Avrech OM, Goldman GA, Rufas O, Stein A, Amit S, Yoles I, Pinkas H, Fisch B. Treatment variables in relation to oocyte maturation: lessons from clinical micromanipulation-assisted in vitro fertilization program. J Assist Reprod Genet 1997; 14: 337–42.

Greenblatt EM, Meriano JS, Casper R. Type of stimulation protocol affects oocyte maturity, fertilization rate, and cleavage rate after intracytoplasmic sperm injection. Fertil Steril 1995; 64: 557–63.

De Vos A, Van de Velde H, Joris H, Van Sterteghem A. In-vitro matured metaphase-I oocytes have a lower fertilization rate but similar embryo quality as mature metaphase-II oocytes after intracytoplasmic sperm injection. Hum Reprod 1999; 14: 1859–63.

Goud PT, Goud AP, Qian C, Laverge H, Van der Elst J, De Sutter P, Dhont M. In-vitro maturation of human germinal vesicle stage oocytes: role of cumulus cells and epidermal growth factor in the culture medium. Hum Reprod 1998; 13: 1638–44.

Hartshorne G, Montgomery S, Klentzeris L. A case of failed oocyte maturation in vivo and in vitro. Fertil Steril 1999; 71: 567–70.

Prins GS, Wagner C, Weidel L, Gianfortoni J, Marut EL, Scommegna A. Gonadotropins augment maturation and fertilization of human immature oocytes cultured in vitro. Fertil Steril 1987; 47: 1035–7.

Wynn P, Picton HM, Krapez JA, Rutherford AJ, Balen AH, Gosden RG. Pretreatment with follicle stimulating hormone promotes the numbers of human oocytes reaching metaphase II by in-vitro maturation. Hum Reprod 1998; 13: 3132–8.

Haghighat N, van Winkle LJ. Developmental change in follicular cell-enhanced amino acid uptake into mouse oocytes that depends on intact gap junctions and transport system Gly. J Exp Zool 1990; 253: 71–82.

Junca AM, Mandelbaum J, Belaisch-Allart J et al. Maturite et qualite ovocytaire: l’apport de l’ICSI. Fecondabilite des ovocytes microinjectes apres maturation in vitro. Contracept Fertil Sex 1995; 23: 463–5.

Lopata A, Leung PC. The fertilizability of human oocytes at different stages of meiotic maturation. Ann NY Acad Sci 1988; 541: 324–6.

Carroll J, Jones KT, Whittingham DG. Ca2+ release and the development of Ca2+ release mechanisms during oocyte maturation: a prelude to fertilization. Reviews of Reproduction 1996; 1: 137–43.

Dominko T, First NL. Timing of meiotic progression in bovine oocytes and its effect on early embryo development. Mol Reprod Dev 1997; 47: 456–67.

How to Cite
Kovačič B, Vlaisavljević V. RESULTS OF IN VITRO MATURATION OF MEIOTICALLY IMMATURE HUMAN OOCYTES IN A SIMPLE MEDIUM. ZdravVestn [Internet]. 1 [cited 17Sep.2019];71. Available from:
Professional Article

Most read articles by the same author(s)