IVF Preparation Cycle


Prior to starting the fertility drugs for your IVF stimulation, there is usually a short 'preparation' (mild suppression) of your ovaries using either low dose oral contraceptive pills-OCPs or Estrogen and/or Progesterone for anywhere from 1-3 weeks. This so-called ‘preparation’ or control of the ovaries (Prep Cycle) tries to keep the ovaries ‘quiet’ or inactive and helps to synchronize the growth and development of your follicles (egg sacs), so that ultimately during the ensuing IVF stimulation we can get more eggs. For example, during the IVF stimulation, we want the vast majority of the follicles growing and enlarging together in sync. We do not want just a few large follicles developing with most others lagging behind. Small follicles (less than 16 mm diameter generally do not give us eggs or give us immature eggs we can’t use). In addition to synchronizing the follicles and ‘resting’ the ovaries, this short prep cycle also allows the vast majority of my patients to be able to fit into this type of HP IVF embryology schedule, so that I can be doing the egg retrieval.


This type of ovarian preparation works very well for most women. On the other hand, this prep cycle can occasionally be very frustrating primarily for women over 38 and/or younger women with a diminished supply of eggs. Sometimes their ovaries do not cooperate and do not respond properly to this 'preparation', instead either forming a temporary cyst or producing estrogen or progesterone levels that are too high. This frustrating problem is much more common in this older age group, as well as younger women with DOR- diminished ovarian reserve. (Fewer eggs for their age). This problem may also occur in women with very irregular menstrual cycles. As women get older and/or have fewer eggs remaining, their pituitary gland in the brain senses this and overcompensates by producing excessive FSH-Follicle Stimulating Hormone, much too early in the cycle (even during the period), which actually then causes the ovaries to release too much estrogen prematurely in the cycle   (even days 1-4). Due to the abnormally high FSH and/or estrogen early in the cycle, these same women are also at much greater risk to ovulate prematurely, or form cysts, even though with the prep cycle medications (low dose OCPs or estrogen & progesterone), we are trying to rest and synchronize the ovaries and block ovulation! In addition, we cannot use strong high dose OCPs to suppress this from happening. Strong high dose OCPs would cause the ovaries to become ‘over suppressed’ and then will not respond to the IVF stimulation medications the following month!

Most women do quite well, but when and if estrogen or progesterone levels are 'too high' at the beginning of a woman’s cycle, or if spontaneous premature ovulation occurs early during the actual IVF stimulation, the ovaries just will not respond well to the IVF fertility drugs (resulting in very few eggs). Under these circumstances, we prefer not to start the fertility drug IVF stimulation, or we will cancel the stimulation cycle, if one is already in stimulation. This is always very frustrating, but it is due to the physiology of the older ovaries and/or ovaries with fewer eggs.  

In summary, this type of IVF preparation & scheduling does not always work out regarding a woman’s irregular or unpredictable menstrual cycles, especially in women over 38 and/or younger women with diminished ovarian reserve (DOR).    So if I have a patient whose menstrual cycle doesn't cooperate with the HP IVF embryology schedule or they form cysts or high estrogen levels, and they want to proceed to an IVF stimulation sooner, one option is that they can always use the River North IVF center, since retrievals are done there throughout the month.

I would still be their physician doing all of the IVF stimulation and ‘monitoring’ management at our offices, but the egg retrieval and/or transfer by one of my partners would be done at River North IVF. I am still the one making all of the clinical decisions. Hope this explanation regarding ‘prep cycle’ helps.