IVF Protocols - FAQ (Part 1)
Saturday, July 26th, 2008As I discussed before, the success rate of IVF depends on many factors including the status of the embryos, the status of the uterus and the nature of the transfer. Furthermore, the first component, the status of the embryos is determined by four factors: the patient’s characteristics, the embryology lab, some random factors and the stimulation protocol, which is the subject of today’s post.
Why is it helpful to stimulate the ovaries rather than just let the eggs develop naturally?
- For one thing, there actually are some IVF cycles in the world done without stimulation. This is called natural cycle IVF. I discussed this in detail in an earlier post. However, the overwhelming majority of IVF cycles are done in conjunction with some sort of ovarian stimulation. The main reason for this is markedly greater success rate and greater number of surplus embryos to freeze for the future. There are also some patients, who just don’t ovulate at all on their own and as such, absolutely require stimulation in order to grow eggs.
What does it mean to stimulate a follicle?
- Eggs remain in storage throughout a woman’s reproductive lifespan. They are encased in structures known as follicles. A follicle is an egg surrounded by a special layer of cells, called granulosa cells. The granulosa cells release estradiol.
- Stimulating an follicle causes it to fill up with fluid, making it visible on ultrasound. On the day of the egg retrieval, a needle is stuck into the follicle and the follicular fluid, along with the egg, are all sucked out into a container.
What is an IVF stimulation protocol?
A protocol is a combination of medications taken in a certain sequence. Think of it a recipe for making the eggs ready for removal.
What are the components of an IVF stimulation protocol?
There are five components.
- Time-regulating component.
- Stimulation component.
- Ovulation prevention component.
- Endometrial support.
- Supplemental adjuncts.
What is the purpose of each component?
- The time-regulating component usually consists of birth control pills. Because IVF is not a one-day process, but rather a multi-week process, it is important to plan things out. Obviously patients have daily lives and must mesh the duties of doing and IVF cycle with their work and travel commitments. Having the patient take birth control pills allows the RE to better control when a patient will have a period and therefore, when an IVF cycle with start. There are other advantages of taking the birth control pills, including fewer cycles postponed because of cysts.
- The stimulation component is the bread-and-butter of an IVF cycle. It is what drives the follicles to grow. Although Clomid can be used, it rarely is, because of its relative low potency and because of deleterious effects on the endometrium. Therefore, the main stimulation medications used in most protocols are injectable medications, such as Gonal-F, Follistim and Bravelle. Dosage is very important. You want to use a high enough dosage to get a good number of follicles, but you also want to use as low a dose as possible because excessively high doses can compromise egg quality.
- The ovulation-prevention component is crucial. Before the standard usage of Lupron, Cetrotide or Antagon, IVF cycles were easily messed up if the patient happened to ovulate on her own before the eggs could be surgically removed. Nowadays, with the liberal use of Lupron, Cetrotide or Antagon, this rarely happens any more.
- Endometrial support usually consists of progesterone of some sort, whether by injection or by vaginal insertion. This is crucial in helping the lining be at its best. Some RE’s also add estrogen supplementation.
- Supplemental adjuncts include minor medications added to tweak the cycle into having a higher success rate. None of these medications are critical, but each RE has a favorite set of these extra ingredients that may or may not boost IVF success rates. In any case, the effect is minor, at best. It’s sort of like cooking something and adding a dash of MSG. Some examples of adjuncts include antibiotics, dexamethasone, baby aspirin or Viagara.




