Minimal Stimulation IVF is a more natural alternative to traditional In Vitro Fertilization and an excellent alternative for women over 40 who respond poorly to traditional hormonal stimulation, have failed traditional IVF, or those who would prefer to use less hormones.
Minimal Stimulation IVF differs from traditional IVF in the type and amount of fertility medications used to stimulate the growth of egg follicles. The goal of Minimal Stimulation IVF is to recruit 2-3 eggs of the best quality using lower doses of medicine. Traditional IVF uses injections of the hormone FSH (follicle stimulating hormone) to stimulate the growth of multiple eggs which are then harvested from the ovary and fertilized in the laboratory (in-vitro fertilization) before being transferred to the uterus as embryos. With Minimal Stimulation IVF, a tablet form of fertility medication called clomiphene citrate is taken for 5 days to increase the natural production of FSH in order to recruit multiple egg follicles. Hormonal injections may be used for a few days but at much lower doses than used in traditional IVF. Although less embryos are produced from minimal stimulation cycles, their quality is thought to be superior- allowing for good pregnancy rates.
ZIFT (Zygote Intrafallopian Transfer) treatment is similar in its initial phases to the treatment cycle followed for In Vitro Fertilization. This includes follicle stimulation with hormone injections, egg retrieval, and egg fertilization in a dish using fresh or frozen sperm. The fertilized egg (called a zygote) is transferred back into the patient’s body immediately after fertilization rather than waiting for it to develop to the embryonic stage in the laboratory.
Instead of being placed in the uterus (as would happen with an embryo in traditional IVF), the zygote is inserted directly into the patient’s fallopian tube. This is done via laparoscopic surgery with the aid of a fiber optic camera to ensure precision. The fallopian tube is where the zygote would normally be located at this stage if the egg had been fertilized naturally after release from the ovary. This fertility treatment allows the zygote to follow a normal pattern of progression and development in a natural environment as it travels down the fallopian tube and implants in the wall of the uterus.
As women age, their eggs are more likely to give rise to a genetically abnormal embryo. Placing embryos in the natural environment of the fallopian tube, as opposed to the artificial environment of the IVF lab, lowers stress on the developing embryo and increases the chance of normal development.
ZIFT has demonstrated effectiveness in women over 40 and those who have not responded to multiple rounds of IVF treatment. At the SMF clinic, pregnancy rates for ZIFT patients are over 40%.