It is important to gain quality eggs for a successful artificial insemination. The more quality eggs we retrieve, the more quality embryos we have to choose from for embryo transfer. The more eggs we retrieve, the higher the risk for complications – ovarian hyperstimulation syndrome (OHSS) can develop. The number of released eggs depends mostly on the ovarian condition – their reserve and also the used hormonal injections for the ovarian stimulation.
There are several options how to individually prepare ovaries for artificial insemination.
Types of ovarian stimulation
Native – natural IVF cycle
When undergoing native IVF cycle, no hormonal stimulation is used. The goal is to retrieve one egg that matures in the woman’s ovary. This method yields relatively low success caused by fertilizing only one egg.
The goal for minimal stimulation is to retrieve 2-8 mature eggs.This type of stimulation is very gentle for a woman (tablets of Clomiphene citrate or low dosage injectables are used). Retrieved eggs are usually fertilized by ICSI. Created embryos are transferred back into the uterus usually after 3 days of cultivation. This method has a 25-35% success rate per transfer. Ovarian hyperstimulation syndrome never develops with this method.
Whom is a method of minimal stimulation intended?
• Couples with indications for IVF treatment method, whose current treatment has not been effective so far
• Couples that didn’t respond to long IVF stimulation protocol
• Women with PCOS syndrome
• Women, whose stimulation was complicated by developing ovarian hyperstimulation syndrome
• Couples that do not wish to use high dosage of stimulating hormones
• Couples whose standard IVF methods were not successful
• Couples for whom the cost factor is the most important
Long stimulation protocol with GnRH analog
This method is a golden standard in the artificial insemination program, utilizing the combination of two kinds of medications. At the beginning of the stimulation, medication suppressing the ovarian function is used and consequently medication stimulating the ovaries is added. This method shows very good success with achievement of adequate number of eggs. This method is more often complicated by the development of ovarian hyperstimulation syndrome. Success rate of this tretment is about 40% per embryo transfer (ET).
Short stimulation protocol with antagonists GnRH
This stimulation protocol is very comfortable, has a lower need for stimulation hormones and the treatment takes less time than with the long protocol. It also utilizes the combination of two kinds of medications. It also usually yields adequate number of eggs; one of the medications can have a negative effect on the uterine lining. Success rate of this treatment is about 35-40% per ET.