On day five of stimulation treatment, you’ll be given blood and ultrasound tests. These continue every day or two until egg collection.
The aim of these tests are for your GP to check follicle size, oestrogen and progesterone levels as well as the thickness of your uterus lining. When all of these are at just the right level and size you’re ready for the all important Trigger Shot.
This can be a really emotional stage of treatment. You’ll hang on every word your doctor says and be counting follicles in your sleep!
Here’s some common questions answered in more detail:
What is the optimum size of a follicle for egg retrieval?
Ideally 18 to 20 millimetres. The larger the follicle, the nearer the egg is ready for collection. As stimulation progresses through the early stages (the first 5 days) the follicles grow more slowly.
Once they reach about 12 to 14mm, they will grow at a rate of around 2mm per day. The average number of follicles is around ten to twelve, but this number can be higher or lower depending upon your age. And not every follicle will have an egg.
How many mature follicles do I need for egg retrieval?
Three to four (18-20mm) follicles.
How thick should the lining of my uterus be?
No less than 7mm. Progesterone given towards the end of the IVF cycle will help to maintain this.
What should my oestrogen levels be?
Every woman is different, but if your oestrogen baseline level on day two to five is 60-150pmol without stimulation, you’re doing just fine. If your oestrogen levels are too high or too low, your doctor will adjust your treatment accordingly. This can mean stopping stimulation if levels are rising too quickly and deferring the Trigger Shot. Retrieving the eggs but delaying embryo transfer until your levels are back to normal. Or in some cases cancel your cycle if you’re deemed at risk from hyper ovarian stimulation syndrome or OHSS.
Again, so much to think about, but keep your eye on the prize!