The Role of the Embryology Lab in an Egg Retrieval Procedure at Boston IVF

Egg retrieval is a crucial step in your fertility journey, and at Boston IVF, our embryology team plays an essential role in ensuring that every part of the procedure is handled with the utmost care. From verifying the identity of the eggs to creating a safe and controlled environment for their development, our lab team is dedicated to giving you the best chance for a successful outcome. Here's a behind-the-scenes look at what happens in the embryology lab during an egg retrieval procedure.

Safety and Identification: No Room for Error

One of the top priorities in the embryology lab is safety and accurate identification of each patient's eggs. To avoid any possibility of cross-contamination between patients, we clear out the lab station between each procedure. When it’s time to handle a new patient’s eggs, we retrieve their specific dish from the incubator.

At this point, two embryologists—one of whom will be the primary person handling your eggs—verify the identity of the dish. This ensures that both experts have confirmed the patient’s details, giving you full confidence that the correct eggs are being processed. This double-check process is a critical step to guarantee there is no confusion at any stage.

Counting Eggs: The Egg Counter System

Once the eggs are retrieved from the ovaries, they’re carefully examined by the embryologist to confirm their presence and count them. Each time an egg is found, the embryologist presses a foot pedal that increments an egg counter on the wall. This provides an ongoing estimate of how many eggs have been collected.  At the end of the retrieval, the physical quantity of eggs in the dish is counted and confirmed, and this number is communicated to the OR. 

Assessing Egg Maturity: Why It Matters

For conventional IVF insemination, all eggs are inseminated, regardless of maturity. However, for patients utilizing ICSI, embryologists only inseminate/inject mature eggs. Therefore, one of the embryologist’s key tasks is to assess whether the eggs are mature enough for fertilization.  
 
Eggs go through different stages of maturation, starting as a germinal vesicle (GV) and progressing through metaphase I (M1) before reaching metaphase II (M2). Only eggs that have reached the M2 stage are mature enough for fertilization, which makes assessment essential for procedures like intracytoplasmic sperm injection (ICSI), where a single sperm is injected directly into the egg. 
To determine an egg’s maturity, the embryologist “strips” away- with hyaluronidase - the cumulus cells (support cells that surround the egg). This allows them to look for the presence of a "polar body," a small byproduct of the egg’s division process, which indicates maturity. If the egg has a polar body, it’s ready for fertilization. 

Preparing Eggs for Insemination

Once the eggs are assessed, they are placed into tiny drops of specialized culture media. This media is designed to mimic the natural conditions inside the body, keeping the eggs safe and stable. The media is covered with a layer of culture oil to prevent evaporation and maintain the right temperature and pH balance for the eggs. 

If a patient is undergoing conventional insemination (as opposed to ICSI), the eggs will simply be placed in the drops of media, and sperm will be added to allow fertilization to occur naturally. For patients undergoing ICSI, the eggs are further prepared to allow for sperm injection, which will take place later at a different station. 

It’s essential to note that while embryologists can introduce sperm to the egg—either through conventional insemination or ICSI—the fertilization outcome ultimately depends on the egg's metabolic response.

Ensuring Optimal Conditions: Temperature and Rinsing

Throughout the entire process, the eggs are kept at human body temperature, around 37°C (98.6°F), which is essential for maintaining their viability. After retrieval, the eggs are rinsed in a culture media specifically designed for insemination and fertilization. This step helps remove the initial media they were collected in and prepares them for insemination in the new media. Each egg typically goes through multiple rinses to ensure it is clean and ready for the next stage of development.

The Magic of Fertilization

For patients undergoing conventional insemination, the sperm is added to the drops containing the eggs, allowing insemination to occur in a way that mimics natural conception. For ICSI patients, our highly skilled embryologists will manually inject a single sperm into each mature egg. While the process may vary depending on the patient’s needs, the goal is always the same: to give each egg the best possible chance of becoming an embryo.

Looking Toward the Future

Every step in the embryology lab, from egg retrieval to insemination, is handled with precision and care. Our goal is to create the ideal conditions for your eggs to develop into embryos, increasing the likelihood of a successful pregnancy. The expertise of our embryologists is crucial in ensuring that every egg is processed correctly, giving you peace of mind as you move forward in your fertility journey.

If you have any questions about the egg retrieval process or what happens in the embryology lab, don’t hesitate to ask. We’re here to guide and support you every step of the way.