|Natural Cycle IVF|
Natural Cycle IVF is a treatment whereby the egg naturally produced by the ovary is harvested without medical ovarian stimulation. In certain cases, a mild ovarian stimulation in combination with antagonists may be necessary in the last days of the treatment in order to avoid premature ovulation.
This treatment is mainly indicated for women who cannot or do not wish to be subjected to hormonal stimulation. It may be particularly advisable for women who had a very poor response to hormonal stimulation in previous attempts. It is a milder treatment than the conventional IVF cycle. Additionally, only one egg is fertilized hence minimising the chances of multiple pregnancy. As ovaries are not stimulated artificially, patients can immediately repeat the treatment in the event of failure. Finally, the costs entailed are lower.
The principal disadvantage of the natural cycle treatment is the lower success rate due to the fewer embryos transferred. This partly cancels the low-cost benefit, as more attempts are required on average to achieve a pregnancy.
Statistics demonstrate that up to 4 natural cycle treatments may be necessary to achieve the same success rate as with an IVF treatment following medical ovarian stimulation. In 'Biodimiourgia', there have been 148 successful egg retrievals during natural cycle treatments over the period 2008-2010. 72 of them led to embryo transfer, while in 38 cases embryos were frozen. Of the 72 embryo transfers, 22 resulted in clinical pregnancies, i.e. 30.5%.