What is Natural IVF?

01 Apr 2015

What is Natural IVF?

Natural IVF refers to IVF which uses fewer drugs that traditional IVF, and works within a woman’s own natural cycle. Conventional IVF uses drugs to shut the menstrual cycle down (‘down-regulation’) before re-starting it again, and uses high doses of stimulating drugs to grow lots of follicles. Natural IVF however does not shut the cycle down but works within it, and the process is focused on collecting the one follicle naturally selected by the body. In Natural Cycle IVF, no stimulating drugs are used and in Modified Natural IVF, small amounts of drugs are used to support the growth of this single follicle.

The history of Natural IVF

Many people see Natural IVF as a new type of treatment, but as a matter of fact, the very first cycles of IVF ever performed were actually Natural Cycle IVF. Louise Brown, the first baby born from IVF in 1978 was in fact born from a Natural cycle IVF. In the years following Louise Brown’s birth, scientists worked hard to improve the success rates of IVF treatment and refine techniques. In so doing, they increased the use of stimulating drugs in order to collect the maximum number of eggs possible. The use of drugs in IVF therefore increased as the, mostly male-led, industry focused on success rates while losing sight of the importance of a high quality experience and minimising side-effects.

For many years it was believed that the high-drug approach to IVF was the only approach. Only in recent years has there been a move back to more natural methods. This has been led by our founder and Medical Director Professor Geeta Nargund, who passionately believes that the IVF industry has a responsibility to use the fewest drugs possible in order to ensure the safety of women undergoing treatment. She has worked tirelessly to improve the success rates of Natural IVF,advance the techniques and encourage the sharing of methods between different practioners of minimal stimulation IVF.

The ‘Quality vs Quantity’ debate

Historically, the focus in IVF treatment has been to collect as many eggs as possible, in order to maximise success rates. However, Natural IVF moves away from this approach and instead focuses on the quality of eggs. This is because of the way a woman’s body works. In a normal cycle, the ovary produces several follicles that are capable of being released. At some point, one follicle becomes dominant and uses the body’s resources to grow and become the egg that is released, while the other follicles shrink back and ultimately die. Stimulating drugs will not create new follicles, but they might encourage existing follicles to grow larger rather than diminish in size and die; however these are not the ‘front runners’ that the body has selected. They therefore often have chromosomal abnormalities and are unable to fertilise or implant. This is the reason that often collecting a greater number of eggs is not always ultimately more successful, as the final number of eggs that are actually viable is the same. It is especially true that for patients who don’t typically respond to stimulating drugs, a higher dose will not help as extra follicles cannot be created from nowhere. For these patients it is more effective to focus on the follicle that has been selected by the body, and to collect this at the right time rather than use unnecessary drugs, which will affect the womb environment for implantation.

What makes Natural Cycle IVF different from conventional IVF? 

Conventional IVF

Natural IVF

4-6 week duration 2 week duration
4-5 weeks of stimulating drugs No stimulating drugs
Collects as many eggs as possible Collects one or two eggs
Recommended 3-month break between cycles No break between cycles
Cycle is shut down and then re-started Cycle is not interrupted
Focuses on quantity of eggs Focuses on quality of eggs
Often not viable for those with low ovarian reserve Allows those with low ovarian reserve to try with their own eggs