The first IVF baby in the world, back in 1978, was conceived during a natural menstrual cycle, without the use of any fertility drugs. The introduction of fertility drugs into the conventional IVF stimulation protocols has resulted in an overall improvement in both the pregnancy and live birth success rates. However, one of the disadvantages of using injectable fertility drugs is that they increase the cost of IVF substantially. Not only the drugs themselves are expensive, but also their use require close patient monitoring that involves more office visits for ultrasounds/blood tests before the actual egg retrieval takes place, as well as more work from the IVF laboratory personnel after retrieval to care for the resultant number of embryos. Therefore, in order to give a chance of pregnancy to infertile couples who simply cannot afford conventional IVF therapy with injectable drugs, minimal stimulation IVF is a more attractive alternative.
The advantages of minimal stimulation IVF include: lower costs, fewer injections and fewer days of monitoring. Even though the cost of minimal stimulation IVF compared to full stimulation IVF is lower, it has been shown that minimal stimulation IVF has decreased overall success rates because there is usually a limited number of available eggs and embryos per retrieval cycle. The minimal stimulation IVF protocol may be beneficial for certain patient populations, such as: high responders who are at increased risk of ovarian hyperstimulation syndrome, patients who are not interested in embryo cryopreservation, patients who want to limit the number of eggs to be fertilized or do not want to discard embryos for ethical or religious reasons and low responders who do not stimulate many follicles during full gonadotropin stimulation.
During minimal stimulation IVF, less expensive medications such as clomiphene citrate or letrozole are used, followed by either a low dose of injectable gonadotropins along with a human chorionic gonadotropin (hCG) trigger shot or just the hCG trigger shot alone. The subsequent basic IVF laboratory techniques of egg retrieval, insemination, embryo culture and embryo transfer in conjunction with progesterone supplementation/pregnancy testing after embryo transfer are identical to those used in conventional IVF cycles.