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In-Vitro Fertilization - Embryo Transfer
(IVF-ET)
STEP 1 - EGG DEVELOPMENT
IVF can be accomplished using a natural cycle without the use of fertility drugs, or during stimulated cycles where medications are given to promote the development of more than one mature egg. If a spontaneous or natural cycle is used, there is approximately an 80% to 90% chance that only one egg will be retrieved. The pregnancy rates are quite low with "natural cycle IVF". Significantly higher pregnancy rates are achieved when more than one embryo is transferred.
The process of stimulating the development of multiple eggs which can be fertilized is called "controlled ovarian hyperstimulation". In order for the body to grow eggs, the brain secretes FSH which acts directly on the ovary to stimulate egg maturation. Fertility medications, such as Gonal-F, Follistim,
Bravelle, Repronex, etc. are essentially concentrated FSH preparations, which are given by subcutaneous (SQ) or intramuscular injection (IM). These medications have been used for over 20 years. They are reconstituted from a powdered form. The method of administration will be shown to you by one of our nurses. These medications cause follicle growth and egg maturation within the ovary.
A follicle is a small cyst within the ovary which houses the egg. A follicle can be visualized and measured with transvaginal ultrasound and the maturity of an egg corresponds with the size of the measured follicle; the larger the follicle the more mature the egg.
FSAC insists on direct, hands-on physician monitoring of all treatment cycles to ensure that experienced hands and eyes are directly viewing these important measurements. The critical decision when to retrieve the eggs depends on these measurements, which at FSAC is
always done by a physician (not a nurse of technician).
The blood estrogen (estradiol) level is also measured when necessary. As follicles/eggs mature, the estrogen level rises. Estrogen levels are useful in determining the degree of egg maturity. The IVF team then evaluates the ultrasound and estradiol measurements and informs you of the next step in the IVF cycle. This may involve either increasing, decreasing or maintaining the same medication dosage. When follicle maturity is reached, you will receive an HCG injection to trigger the final stage of egg maturation.
Another medication commonly used in IVF is gonadotropin releasing-hormone analog (GnRHa), or Lupron. During a normal menstrual cycle, the hormone GNRH causes the brain to release LH and FSH. While FSH acts directly on the ovary to produce follicles and estrogen, LH acts on the ovary to promote the final stages of egg maturation and allows ovulation to occur. When Lupron is given there is first a large increase in FSH, followed by a decline a few days later. This process is referred to as
"down-regulation." When a down-regulation protocol is used, LH and FSH are first suppressed by Lupron for approximately 10 days. After Lupron, ovarian stimulation is begun and more eggs will reach maturity at about the same time. When used this way, Lupron is started between days 21 to 24 of the menstrual cycle. Women will then have a menstrual period approximately one week later, continue the Lupron through their menses, and then begin FSH injections to stimulate egg growth. In some women, oral contraceptives may be administered for 3 to 6 weeks before Lupron administration.
Several studies, including data from our own experience, support the notion that Lupron and FSH combination protocols result in the highest pregnancy rates for IVF. Temporary side effects of Lupron include menopausal symptoms such as headaches, mood swings, hot flashes, vaginal dryness and irritability. However, the side effects are usually not severe and resolve once the estrogen levels begin to rise during ovulation induction. Occasionally, Lupron is started on day 2 or 3 of a menstrual cycle along with injectable FSH in what we call a
"flare" protocol. This works well for some patients by taking advantage of the initial 2-3 day increase in FSH once Lupron administration begins.
Human Chorionic Gonadotropin (HCG, Profasi, Pregnyl) is
injected before egg retrieval. HCG is a hormone produced by pregnant women. This hormone is very similar to the hormone LH, which is produced by the brain to trigger ovulation in normally cycling women. The final maturation of the eggs requires an LH surge, which can be mimicked by injecting HCG 35 hours before the egg retrieval. The dose of HCG varies between 5,000 and 10,000 units and is given by intramuscular injection.
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