Egg retrieval day is an exciting and anxious time. The success or failure of an IVF cycle depends on this moment. From your first negative pregnancy tests to the infertility diagnoses, every shot injected, all the stimulation medications, all the financing, and trauma of infertility- all of it has been leading up to this day. 

You’ve been so INVOLVED up to this point. Administering shots and going to your checkups made you feel “in control” (even if that is an illusion). But then you arrive at the clinic for retrieval, and it’s all out of your hands. 

It’s even out of your physician’s hands. Your eggs are about to pass through a tiny window, into the hands of an embryologist you have never met. 

You are usually asked to arrive at your clinic two hours ahead of your retrieval. You will be asked to fast for at least 12 hours. Once you get checked in and changed into a not-so-fancy robe, you’ll be asked to empty your bladder before being wheeled into the operating room.

What happens in prep for Egg Retrieval? 

The Embryologist will do a “time out” through the tiny window that leads to the sterile lab. They will confirm your name, date of birth and IVF cycle plan with the physician. Then you will start to go under, as the anesthesiologist puts you “to sleep”. 

After you are comfortably asleep, the nurses, medical assistants and physician will drape all of your exposed skin with soft sterile towels. The vagina is washed and prepped for the ultrasound guided transvaginal oocyte retrieval. The physician positions the gooseneck light, and the OR lights are turned down low for the retrieval to begin!

What happens during Egg Retrieval?

In short, the Embryologist goes hunting for eggs. They look for eggs in every shape and size and depend on eggs being surrounded by a nice “cloud” of fluffy, nurturing cumulus cells. 

In general, your last scan tells your physician and embryologists how many eggs to expect. They make that determination based on the number of follicles over 14 mm. They are also seeing if the “small” follicles did or did not hold a mature egg.

As the tubes of follicular fluid are handed through the window, they are taken into a dark, warm, and humid environment. They then pour the fluid into a petri dish and start examining it closely under a microscope. As an Embryologist finds eggs, they count to your clinical team; One, Two, Three, and so on. 

Mostly, the number of eggs expected are retrieved and sometimes, you get a huge surprise and get more eggs than expected! Occasionally, there are retrievals that yield no eggs. There are several reasons that can occur; something went wrong with the stimulation protocol. Maybe only one egg was expected, but it can’t be found. Perhaps the patient didn’t time the trigger correctly or the surgery started late and the patient ovulated, or the trigger didn’t “absorb” properly. Maybe it’s a rare case of empty follicle syndrome. Whatever the cause, “no egg” retrievals are devastating.

At the same time as your retrieval is happening, the sperm for your egg insemination is being processed. Maybe it is being thawed, or in the case of fresh samples, it is being separated from the semen of the ejaculate and being prepared so the best most “motile” sperm will be available for later use.

What happens in the lab post Egg Retrieval?

After the eggs are collected they are washed, and sometimes they rest in the cumulus cells in an incubator hoping for any last – or slow maturation to happen, before they are processed further. 

In conventional IVF the eggs stay in the cumulus until they are combined with sperm cells. But if ICSI will be performed, then they are “striped” of the cumulus cells, graded, and their quality assessed. 

On average, about 80% of the eggs that are retrieved will be mature enough to fertilize. To assess egg maturity and quality, an embryologist dissolves the cumulus cells from around the eggs with an enzyme. Then gently swish each egg cell up and down in a tiny pipette, about the width of a sharp pencil lead. In the end they only want to see one single, clean cell- THE EGG!

Then only the mature and healthy eggs are then separated for fertilization. Mature eggs are referred to as “MII” ie. “meiosis two” ready oocytes. Besides seeing nice mature MII oocytes, the lab may see slightly immature eggs, called MI (Meiosis I) or very immature eggs called “GV” (ie geminal vessicle). Unfortunately, sometimes we see eggs that have fractured zonas, or are severely compromised due to vacuoles, dented cyctoplasm, or other abnormalities. 

Whether you and your physician opt for ICSI or conventional IVF, or if your lab only offers ICSI, your eggs will be combined with your partner or donor sperm within a few hours of the egg retrieval. This is referred to as “insemination” and it is not the same as fertilization. 

To learn more about insemination and your choices of ICSI or IVF, click here.