What Is the Role of Mini IVF?
From Dr. Paul Gindoff of Chelsea Fertility NYC
About two decades ago we started performing IVF on patients without using fertility drugs, otherwise known as a natural cycle IVF. The objective was to collect the single dominant follicle egg and use this egg to produce an embryo that would offer a reasonable pregnancy rate in younger woman with tubal factor.
Pregnancy rates using natural cycle IVF were about 20%, but varied with the age of the patient. During this time, we learned a lot about IVF and egg retrievals with minimal stimulation, or essentially one follicle to aspirate. However, the major pitfall was pre-mature ovulation rate. That is, the patient would lose the egg by ovulating before we could perform the egg retrieval. So even after 36 hours from trigger shot, the odds of not getting an egg were 40% – this made the program untenable and not sustainable.
It was only about 10 years ago that a new drug was introduced that has had amazing impact on the efficiency of natural cycle or mini IVF. This drug called GnRH antagonist, trade name Ganirelix or Cetrotide, allows efficient egg harvesting and nearly non-existent premature ovulation. By combining natural cycle monitoring or minimal stimulation with GnRH antagonists, the efficiency of harvesting even one follicle for one egg has dramatically skyrocketed, making this a sustainable cost- effective option for some patients.
The best candidates for mini IVF are those patients who only need one embryo to have a good pregnancy rate, i.e. women under 35 years of age. Another group that can benefit from natural cycle IVF are those women with very poor ovarian reserve, who even with extremely high doses of costly injectable fertility drugs do not yield more than one or two eggs. Thus, it is cost-effective to treat both these groups and utilize all the comprehensive treatment power of in-vitro fertilization even for one egg and embryo.
The clear advantage in utilizing mini IVF is cost, with respectable pregnancy rates between 20-30% depending on age for good prognostic patients. The down side is that the cycle will not yield supernumerary embryos for a freeze, and will be very limited in supporting a management plan that involves pre implantation genetic testing or screening as multiple embryos are needed for both.