THE ANTAGONIST CYCLE
‘Day One’
On the first day of your cycle, which is the first day of your period when you have a full flow prior to lunchtime, you should call Eve Health. Should this happen over the weekend, don’t worry – you can call us on Monday morning and we will arrange to see you as soon as possible. We always make time to see patients who are in a treatment cycle, so please do not worry that there will be no appointment times available.
The start of your cycle
Once you have notified Eve Health you will be either (a) come into Eve for a transvaginal scan between days 2 – 4 , (b) have a blood test, or (c) we may ask you to come in for both a scan and a blood test. These ‘baseline’ tests are to determine that your ovaries are ‘quiet’ and your body is suitable to start the medications.
FSH injections
Following this initial scan and/or blood test you will start your medications. The first injection will usually be FSH (Follicle Stimulating Hormone). This medication will stimulate the follicles to grow and mature – hopefully each with an egg inside. The FSH injections do not create any more follicles than are already present in your ovaries for that month. FSH injections are usually given in the morning at a consistent time that is convenient for you. FSH must be kept refrigerated.
Most of these FSH medications are a daily injection, except for Elonva which is a long acting FSH and will provide the equivalent of 7 days of FSH. This medication is only suitable for some patients and most women require the daily form of FSH. Some of the medications come in pre-loaded pens whereas some require mixing with a syringe. Your nurse will demonstrate your particular medication to you.
Adding the Antagonist injection
Approximately 5 days after your first dose of FSH, you will start your antagonist injections. This medication stops ovulation to ensure that your eggs remain in the follicles until we are ready to take them. The antagonist is usually given at 9pm. Orgulatran should be kept in a cupboard at room temperature, or refrigerated for Cetrotide.
Your first scan after starting FSH injections
You will have an ultrasound scan after approximately 5 – 7 days of FSH injections to check the development of the follicles. A transvaginal scan will be performed to measure the size of each of the follicles and to check that the lining of your uterus (the endometrium) is thickening. The endometrium is important for implantation of an embryo. You will generally be back for scans and or blood tests every second or third day.
How quickly you respond to FSH injections
At each visit, your response to the treatment will be monitored. Your FSH dose may changed or the antagonist withheld until we see an appropriate response. Do not worry if this happens – it doesn’t mean that you will not respond but just indicates the need a for a few extra days of medications to achieve a better response. Conversely, you may have responded more quickly than anticipated. If so, you may not need many other visits before egg collection.
Blood tests during your cycle
Blood tests are performed to correlate your hormone levels with the ultrasound findings. This allows us to detect any signs of premature ovulation or unexpected endometrial changes. The blood tests have to be performed by our pathology services – if you have them done in another laboratory, you will incur additional charges by that provider.
Triggering ovulation
Approximately 12 -14 days after starting FSH your follicles should be large enough to proceed to egg collection. A mature follicle is approximately 16 - 20mm in diameter. . You will be instructed to take a final injection (also known as your Trigger injection) at a specific time. The time of your trigger injection will be based on the time of your egg collection, as there must be an exact number of hours between the trigger and the egg collection. This last injection ensures that the eggs inside the follicles undergo a final maturation so that they are suitable for fertilization once collected.