IVF Developments and Future prospects

In vitro maturation of oocytes

In vitro maturation (IVM) aims at achieving the final maturation of eggs within the laboratory with ultimate target their optimal fertilization. The immature eggs are obtained by puncturing follicles of small diameter. A similar method involves in vitro maturation of primordial follicles derived from frozen-thawed strips of ovarian tissue, in order to isolate and mature the enclosed oocytes.

In the first method (IVM), maturation only takes a few days, while the second (primordial follicle growth) requires special systems of extended culture. In both cases, the ultimate goal is the production of fully mature fertilizable eggs.

The method is quite promising in the field of ART, especially for special groups of women (e.g. women wishing to secure their fertility potential at a young age by freezing ovarian tissue for use later in life).

For now, the method is still at an experimental stage and its efficacy is limited. The main interests of IVM research groups are the enhancement of collection of immature egg from small follicles, improvement of culture conditions and guarantee that in vitro matured eggs are healthy and normal.



Cryopreservation of stem cells

The research interest of several scientific teams has been recently focused on the ability of certain embryonic cells to multiply and differentiate in culture leading to the formation of organ tissues. The embryonic stem cells are derived from the inner cell mass of the blastocyst.

Experimental data have demonstrated the ability to direct the differentiation of these cells, under specific culture conditions, into haemopoetic cells, neurons, hepatocytes and myocardium cells.

Further development in this area is an exciting scientific challenge as it would form the base for new therapeutic prospects for many diseases.

At present, pluripotent stem cells from the umbilical cord of newborns can be isolated and frozen for a possible future transplantation and treatment of blood diseases.



Cryopreservation of ovarian tissue

The method intends to preserve a woman's reproductive ability prior to aggressive treatments for malignant conditions, aiming to restore normal ovarian function in the future.

A small part of the ovary which contains several immature follicles is removed by laparoscopic surgery or laparotomy and is frozen in Cryopreservation banks.

This confers the following future prospects:

  • In vitro maturation of primordial follicles and immature oocytes until they reach the stage of full maturity and are able to be fertilized by IVF.
  • Autografting, i.e. transplantation of the tissue in the same woman in order to restore her ovarian function.
  • Heterografting, i.e. transplantation of the tissue in another woman who has lost her reproductive ability.

Freezing of ovarian tissue is internationally accepted, but restoration of ovarian function following transplantation is still under investigation. Progress is continuous giving hope to young cancer patients, who may wish to have a child later on in life.




Transplantation of ovarian tissue

A piece of frozen ovarian tissue can be transplanted in the body of the woman from whom it was taken (autografting) after total treatment from a malignant condition.

When the location of transplantation is the anatomic location of the ovary the transplantation is termed orthotopic. If the tissue is replaced in a different part of the body the transplantation is termed heterotopic. In heterotopc transplantation the ovarian tissue can be grafted in a more convenient anatomic position (e.g. under the skin) which facilitates oocyte recovery from follicles developing under drug stimulation.

Experimental data have shown restoration of ovarian function for a limited period. Researchers investigate the factors that are responsible for the re-establishment of the function of the transplanted ovarian tissue and the restoration of the woman?s reproductive ability. Autologous and heterologous transplantation is only recommended in special cases after the approval of specialized scientists.

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