The first IVF pregnancy, in 1978, that resulted in the birth of Louise Brown was a Natural Cycle-IVF (NC-IVF) protocol where no ovarian stimulation drugs were used. That changed during the 1980s when doctors began to use fertility stimulating drugs, and super-ovulation became associated with much higher pregnancy rates. The use of such drugs then became universally adopted.
Since the mid-1990s the interest in NC-IVF has been rekindled, initially for use with women who failed to achieve super-ovulation, and then most recently as a means of lowering the cost of IVF services.
Mini-IVF represents an approach that fits between natural cycle-IVF and conventional IVF.
Mini-IVF is an Artificial Reproductive Technology (ART) procedure that uses lower doses of stimulation, therefore collecting less eggs than conventional IVF.
While conventional IVF aims to produce many eggs for retrieval, Mini-IVF uses a lower dose of hormone injections with the intent of retrieving fewer than 6 eggs. As only a small number of eggs will be collected, the TVOA (Trans-Vaginal Oocyte Aspiration) can be performed using a local anaesthetic rather than being admitted to hospital for a general anaesthesia. This results in a much quicker recovery and enables the option of doing multiple cycles back to back.
With this approach, the cost per cycle is lower, and the risk of Ovarian Hyperstimulation Syndrome (OHSS), one of the main complications to IVF with standard stimulation protocols, is reduced.
Evidence from clinical trials have demonstrated improved chance of success using this approach in women with a poor ovarian reserve.
Conventional IVF is designed to produce multiple embryos that can be frozen during your cycle. Therefore, if your initial cycle is not successful, these can be used during a frozen embryo transfer (FET) giving a higher cumulative chance of pregnancy. With Mini-IVF, you are less likely to have any frozen embryos for future cycles so the chance of pregnancy per cycle is reduced.
There is also a greater risk of having no eggs to fertilise (approximately 5% of cycles), or no embryo to transfer. Not every egg that is produced will be suitable for IVF/ICSI, and not every egg that is fertilised will develop into a suitable embryo to transfer. The result of this is that the cancellation rates of Mini-IVF cycles are higher.
Mini-IVF stimulation starts on day 2 of the cycle and is designed to encourage the growth and development of a few follicles. During a Mini-IVF cycle, as with conventional IVF, there will be routine monitoring, ultrasound scans and timed ovulation, but slightly less monitoring is necessary.
Mini-IVF aims to result in the production of only a few dominant follicles. As a result, the TVOA can be performed quickly, reducing patient discomfort to the point where it may be safely and comfortably achieved without the need for sedation or general anaesthesia.
The rest of the cycle then proceeds as with conventional IVF, in that the laboratory process of fertilisation with IVF or ICSI is the same. Then, providing a suitable embryo is achieved, it will be transferred into the uterus.
Women are considered ideal for Mini-IVF if they experience poor response to stimulation. In this group, the high levels of stimulation normally used fails to promote the growth of multiple follicles.
It may also be considered favourable to patients outside this criteria for the following reasons:
Not all women are appropriate candidates for this type of IVF cycle; your fertility specialist will discuss your specific situation with you. Circumstances do occur, most commonly related to variations in pelvic anatomy, which make transvaginal oocyte aspiration (TVOA) more difficult. In those situations, patients are not suitable for TVOA under local anaesthetic and would need to be admitted to hospital for the procedure.
Patients with normal ovarian reserve will have a better chance of success with conventional IVF treatment protocols.
If you are a patient at Fertility North, ask your specialist whether Mini-IVF is suitable for you.
If you wish to know more, email Fertility North at email@example.com or call us on (08) 9301 1075.