Natural cycle IVF is a treatment cycle where we plan to collect the one single egg that develops naturally every month, without giving you any of the stimulating hormonal drugs given in a conventional IVF cycle. In some cases hormones in minimal doses may be considered, to facilitate the collection of the egg and to prevent premature ovulation. Monitoring during the cycle, egg collection and subsequent embryo development in the laboratory will be no different compared to conventional IVF.
WHO COULD BENEFIT FROM NATURAL IVF?
For women who are naturally ovulating and medication is unlikely to help them develop more than one egg in their ovaries, a Natural IVF may be most appropriate. This is particularly the case in women with a very low ovarian reserve, in older women or in those who have previously had IVF with the use of drugs but still only developed a single follicle.
WHICH ARE THE DRAWBACKS OF NATURAL IVF?
The main drawback of natural IVF is the high cancellation rate. This is either because no egg is being collected due to a higher chance of premature ovulation, or it is because the egg collected does not get fertilised and therefore there is no embryo to be transferred.
It is important you are aware of the following:
It takes almost 5 natural cycles for every 1 stimulated cycle to achieve a live birth.
The overall live birth rate for Natural IVF is <5%.
44% of Natural Cycles result in NO egg being collected.
57% of Natural cycles result in NO embryos being transferred.
There is no difference in later pregnancy risks such as preterm delivery or low birth weight compared to conventional IVF.
Source: (HFEA data 1991-2011: Sunkara et al, Human Reproduction, 2016)