“Mini-IVF” or “IVF-Lyte”?

As I read patient experiences with mini-IVF (also called Mini-stim IVF) on infertility blog sites, it is clear that physicians are doing different things that they call mini-IVF. Generally patients are describing an IVF cycle with limited medications to produce a limited number of eggs. This reduces costs and likely benefits some patients, but does not provide them with all the advantages of Mini-stim IVF.

Mini-stim IVF essentially uses the idea that the body largely selects the best (baby quality) eggs before the cycle even starts. Medications enhance the development of these eggs, but are utilized in small enough amounts that they do not distort the process of follicle and egg development. High doses of medication may either enable chromosomally abnormal eggs to develop or lead to abnormalities in the chromosome division process in the cytoplasm of the egg so that errors in chromosome division are made. Theoretically, very high doses of medication may also cause the eggs to produce an imbalance of biochemical products that interfere with the embryo development process.

Fauser looked at two groups of young patients who were randomized to receive low or high dose gonadotropin ovulation inductions. All embryos were biopsied for PGD prior to transfer to determine chromosomal normality. Patients receiving the higher doses of medications produced more eggs and more embryos, but the number of normal embryos in the two groups was the same.

Animal studies have shown that the likely best eggs are evident before the cycle starts. High doses of medication may primarily partly rescue eggs that were already destined to NOT become babies. Having more eggs during the IVF process makes everyone feel better, but does not always enhance the likelihood of success.

We believe this observation is especially important in the two primary groups that we see as the best candidates for Mini-stim IVF: older women and couples with isolated male or tubal factor. Women with decreased ovarian reserve (elevated FSH level, low AMH level, low AFC) for any reason (age, surgery, genetics) are often treated with a truck-load of FSH containing medications and still produce a handful of eggs. Usually those eggs will morphologically reflect that decreased ovarian reserve and the high doses of gonadotropins. With Mini-stim IVF we can likely produce as many normal embryos, with a much easier ovulation induction for the patient (less monitoring and less medications) at less than one-third the cost. The best data currently available suggests that the pregnancy outcome is similar with these two approaches in this patient group.

Couples with good underlying fertility and isolated sperm or tubal factors will likely produce at least one very good egg with a Mini-stim cycle. Isolated male factor is completely compensated for by using ICSI. Similarly, most tubal factors are compensated for by putting the sperm together with the egg. (Closed hydrosalpinx and endometriosis create other problems.) In this setting, one good egg is often all that is needed for pregnancy. The pregnancy rate is likely higher with conventional IVF than with Mini-stim IVF, but not higher enough to compensate for the lower cost and increased ease of the cycle.

Other patients will choose to do Mini-stim IVF because of its lower cost compared to conventional IVF Centres in Singapore or instead of self-paying for expensive components of an infertility work-up such as laparoscopy. If Mini-stim IVF is not successful, these patients can then go on and utilize conventional IVF.

So how do you know if you are doing “mini-IVF” or “IVF-lyte”? The main tip-off is the gonadotropin dose. For mini-IVF, the dose is usually 1-2 ampules of gonadotropins (75-150 Units) per day. Oral medications are also often used to enhance the patient’s own production of FSH. If you are using much more medication, then you are most likely doing IVF-lyte. Again IVF-lyte can still be helpful to patients, it is just different from Mini-stim IVF and the philosophy underlying it is closer to conventional IVF than to Mini-stim IVF.