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The curse of the Empty Follicle Syndrome

Updated: Dec 7, 2020

Many frustrating situations may occur during an IVF cycle: from low response to having the cycle cancelled, from retrieving immature eggs that don’t fertilize to embryos that don’t develop properly.

But by far, one of the most dreaded scenarios is the one where you wake up from your egg retrieval anaesthesia only to be told your follicles were empty.

Wait, what??

“But I’ve seen them on a scan the day of the trigger: they were nice and plump and the tech measured and counted them!

I even had my Estrogen level measured and it totally indicated my follicles were actually hosting eggs.

HOW can this even be possible?!!”

Well, here’s a great question: IS it possible? Does the Empty Follicle Syndrome really exist or is it just an excuse? And if it does exist, are there any ways to prevent it from happening?

The Empty follicle syndrome (EFS), is a very disappointing condition in which no eggs are retrieved from mature follicles after ovulation induction in in vitro fertilization (IVF) cycles. The occurrence is pretty rare, but highly disappointing. EFS has been first recorded in 1986, and has been considered pretty controversial ever since.

Medical literature classifies Empty follicle syndrome in two categories: false and genuine.

Genuine EFS is defined as a failure to retrieve eggs from mature follicles, in spite of a normal follicular development (constant growth, satisfactory Estrogen levels on trigger day) and an optimal Beta HCG level measured on the day of egg retrieval (as proof the trigger shot has been properly administered and correctly timed)

False EFS includes all cases in which the above conditions have been met, and in which human error or pharmaceutical inaccuracy may be suspected.

To put it simple:

· did your scans show proper growth progression of your follicles throughout your stimulation?

· did you have an Estradiol level of at least 200 pg/ml per “mature” follicle on trigger day?

· was your trigger shot within the expiry date and properly stored before administration?

· was your egg collection timed correctly, 36 hours post trigger?

(I am not going to include the level of Beta HCG measured the day of egg retrieval, because clinics do not regularly do that, unless they participate in studies)

If your answer to all four questions above is YES, and you still got no eggs retrieved during that cycle, your case would more likely classify as False Empty Follicle Syndrome.

Basically, there is no way there were no eggs in there, and if none were collected, it most likely is due to a human error: improper administration of the HCG trigger, bad timing of the egg collection, incorrect flushing and/or collecting the follicle.

Frustrating as it is, there is some silver lining here: Empty Follicle Syndrome doesn’t appear to represent a permanent condition per se, because many cases occur sporadically. Therefore, chances are it was a fluke and you’ll get a better outcome on a future IVF cycle.

It was suggested that in some women, early oocyte atresia (follicular disintegration) may occur even in the presence of a normal hormonal response (good Estrogen level growth) or that some women may need longer exposure to Beta HCG in order for the egg to detach from the follicle. This theory was challenged by studies that showed employment of rescue protocols led to retrieval of follicles later in the same cycle.