Dr. Miguel Dolz, gynaecologist and manager of FIV-Valencia clinic, gave a talk about the pros and cons of IVF and ICSI techniques and about how the second of them has become the most used technique in the reproductive medicine.
The classic in vitro fertilisation was originated to solve certain problems of infertility such as the obstruction of the Fallopian tubes, problems of endometriosis or in case of failure in artificial insemination. For its part, male factor inferility cases, in which the ICSI technique (Intracytoplasmic Sperm Injection) was used, cause the 40% of fertility problems in couples (within this 40%, 15% are severe cases). These are the cases in which ICSI should be used.
Nevertheless, in Spain approximately 80% of cases are solved by ICSI (although the reproductive problems are of another kind) and 20% by classic IVF. Dr. Dolz wonders the why in his talk.
As can be seen in the table 1, in vitro fertilisation shows better fertilisation rates and a higher number of good quality embryos. Failures occur exceptionally in both techniques.
Table 1: Cycles of IVF and ICSI during 2009 and 2010 in FIV VALENCIA
|Cycles of IVF-ICSI 2009-2010||IVF||ICSI||p|
|Cycles(N=470)||270 (60%)||200 (40%)||ns|
|Fertilisation rate/Inseminated oocytes||72.6%||76.1%||ns|
|Fertilisation rate/Retrieved oocytes||70.5%||60.6%||0.001|
|Failures of fertilisation||3 (1.1%)||3 (1.5%)||ns|
Dolz also thinks about the Cochrane review of the year 2004, in whose conclusions noted that the fertilisation rate was higher in IVF cycles (when it is not a male factor). Furthermore, in the case of women over the age of 36 better results are obtained by using classic IVF as regards pregnancy rates, implantation and labour per started cycle.
But, why? According to different authors, oocyte quality worsens with age, egg reserves decrease and also its potential and its regenerative capacity.
With ICSI they are exposed to more aggressive environments than with IVF. Hyaluronidase is used with the aim of killing cumulus cells. Moreover, this stress is also determined by the microinjection of PVP and by the peeling process. The oocytes of women with an advanced age will be more affected by all those processes.
The increase of de novo chromosomal abnormalities and disturbances that can modify the genomic imprinting in relation to ICSI have also to be considered.
Dolz concludes that IVF is as effective as ICSI. “Both techniques have as its objective to achieve the fertilisation of gametes. ICSI begins where IVF ends.”