IVF Ovarian Stimulation Protocols
So different clinics and different clinicians will all tend to use very slightly different IVF treatment protocols. Different protocols are used in IVF because there are different approaches to stimulating the ovaries, but ultimately, a period of downregulation has to occur to prevent natural release of eggs while stimulating the pool of follicles in the ovary to ensure that a number of follicles develop; maximising the chance that you’re going to get a good number of eggs from the ovary in the IVF cycle. This has to be done safely and depends on a number of parameters. Previous success is often looked at when developing protocols with patients, but overall ovarian reserve is critical to knowing how to stimulate the ovaries safely.
A woman will tend to take a series of injections to both stop ovulation from happening, whilst also stimulating the ovaries to produce follicles which grow and produce mature eggs. The injection, which causes the follicles to stimulate and to grow is called recombinant FSH, or follicle stimulating hormone.
This is given in very much higher doses than the natural body will release in a normal physiological menstrual cycle. And of course, it will depend very much on your egg reserve as to the dose that you’re recommended. There are different types of protocols used in clinics. Short protocols will tend to be a far safer way to stimulate the ovaries if a patient has a very high ovarian reserve.
And longer protocols can be used when patients have lower ovarian reserves. Though this is not absolute, and your clinician may make a decision based on so many different parameters in your fertility history. But ultimately the goal is the same – trying to stimulate the follicles that are resting in the ovaries to grow and recruit, and this is monitored using ultrasound.
And at that point, you then see whether the response from the patient in that first IVF treatment cycle is what you expect.
Each IVF cycle is aiming to reach egg collection, and the vast majority of patients that start stimulation with medication will achieve that. During the tracking phase, ultrasound is used to monitor the resting follicles as they enlarge under the influence of follicle stimulating hormone. The medications that you inject will gradually encourage those small resting follicles to enlarge over a period of weeks. This is checked with ultrasound, and once the follicles reach a critical size, you will trigger ovulation to happen in the body using a further medication. This trigger injection is time critical to then coming through to the clinic for a collection.
The egg collection is a surgical procedure. It can cause a little bit of bleeding and discomfort. Very rarely are patients left with severe pain, but if a lot of follicles are found on the ovary, patients may feel rather bloated and uncomfortable following the procedure. This is the few, not the many.
The eggs once collected from the ovary, using ultrasound and a needle piercing the follicles which have enlarged on the ovaries while the patient is asleep, will then be passed into the laboratory for the next phase to take place in the IVF cycle.