I was very concerned this morning that this 26 mm follicle was indeed a cyst. I have been spotting for days and my E2 levels were very low for one follicle. I emailed my clinic this morning to find out and this was the response:
Here is an article I found on good follicles verses bad follicle cysts: I think it is safe to assume I shouldn't have taken that trigger shot this morning. Wish I would have asked for levels yesterday when she mentioned it was low. Hoping that the trigger won't effect it and my AF will still show up soon.
Three different terms that are used in overlapping fashion are cyst,
egg and follicle. The EGG is that all-important biological specimen that
contains half a woman’s genetic information. In my
simplified view
of human reproduction, a woman randomly shuffles all her DNA (the stuff
that influences her body to develop blue eyes, a cute little nose and a
fondness for puppies) and packages exactly half of it into each egg.
The goal then, is for the egg to unite with one of her husband’s sperm,
which very coincidentally contains half of HIS genetic information. The
final product is a baby, a tiny person with genetic information from
both parents. We can’t see eggs on ultrasound, because eggs are smaller
than a speck of dust. What we CAN see are FOLLICLES. Imagine a follicle
to be like a water balloon with a speck of magic dust (the egg) inside
it. A woman is born with about a million of these packed inside her
ovaries. Each month after she reaches puberty, some of these follicles
start to fill up with water like expanding water balloons. Most will
grow just a little and then fizzle out. However, the biggest one, which
gets crowned with the title of THE DOMINANT FOLLICLE will grow from
microscopic size up to about 20mm, roughly half the diameter of a golf
ball. Once it reaches that size, it should burst and let the egg fly
out. Under ideal conditions, the egg gets slurped up into the Fallopian
tubes where it can hopefully meet a nice eligible sperm and then off
they go into the uterus to implant.
So when doing ultrasounds, I’ll often report to my patients, “Great
news! You are growing two eggs in each ovary for a total of four, giving
you four chances at pregnancy this month! Right now they are still a
few days away from being ready.” When they ask how I know that, I answer
“Based on the measurements.” This is where the patients naturally
assume that by measurement, I am talking about the size of the eggs. But
as you probably realize know after having paid attention to what I just
wrote, I’m actually talking about the size of the follicles.
Now that we have clarified the relationship between an egg and a
follicle, where does the term CYST come into all this? A cyst can be
defined as a CLOSED SAC, sometimes filled with a substance like fluid,
air or blood.. So actually, follicles are cysts. They happen to be GOOD
cysts as opposed to bad cysts. So medically, CYST is the term we use to
generically refer to many different sac-like structures, not just
dust-filled water balloons. Cysts can be found in many places like in
breasts, under the skin, in the cervix or in the brain. Furthermore,
ovarian cysts can be the good kind (follicle) or bad kinds, such as
endometriomas which are harmful cysts filled with fluid that looks like
chocolate syrup.
Now here’s the tricky part. A follicle and a simple cyst look
identical on ultrasound. So using just one single ultrasound, nobody can
say for sure whether we see a good follicle or some other type of
cystic structure. However, if you look again on ultrasound three days
later and see that the water balloon has grown from 14mm to 19mm, then
you get a pretty good idea that it is a growing follicle. If instead,
your repeat ultrasound shows nothing, then it turns out that it was most
likely a cyst which has gone away on its own.
The typical protocol for patients who are taking strong fertility
drugs is to do a cyst check prior to starting the stimulation
medications. This is an ultrasound done on about day #3 of the cycle.
What we want to see is nothing. What we don’t want to see, but sometimes
do, are cysts and if they are big enough, it tells us that this is not a
good month to do a cycle, so we postpone things.
Finally, let’s go back to the idea of how it’s normal each month for a
single healthy water balloon to grow to a mature size and ovulate its
precious contents. Remember, I alluded to this being the dominant
contender out of several contestants which start the race, meaning most
women will start growing a lot of potential follicles each month, but
without medications, they should just ovulate one (or occasionally two).
The other follicles should quickly all fizzle out and not even grow to a
visible size. However, there are some women with a common medical
condition in which the ovulation process goes haywire. Instead of one
dominant follicle emerging and the others all shrinking to nothingness,
what happens is that a whole bunch of the follicles keep growing, but
none really make it to mature size. So instead of seeing one large 20mm
water balloon and nothing else, you see a whole bunch of 12mm follicles
stagnated in their growth. Some of you have probably already guessed
that this condition in which multiple small ungrowing non-ovulating
follicles are seen in the ovary is called POLY-CYSTIC OVARY SYNDROME,
but that’s a story for another day.
