Wanna Take a Peek
at What Goes on Inside
The Embryology Laboratory?


After all, this is where your eggs, sperm, and embryos spend their time away from your body.


What goes on behind that mysterious door?

Since your eggs and embryos can spend more than a week in the IVF laboratory, we think you may be interested in knowing what goes on behind the scenes.​

​

Let's take a look, one day at a time (for a total of 9 days), at what goes on inside the IVF laboratory where your gametes (eggs and sperm) and embryos are developing and are being taken care of.​

​We use the age of your embryos as a point of reference whenever we discuss events in the IVF lab. Therefore, Day 1 refers to a 1-day-old embryo (fertilized egg), Day 3 means the embryo is 3-days-old, and so forth. The day that eggs are retrieved is referred to as Day Zero (0) since we are working only with gametes (eggs and sperm) at this point and there are no embryos yet to relate to.

​For each day, we specify the standard laboratory procedures practiced at all IVF Centers including ours, and we also point out additional procedures that we do differently at Rockefeller Fertility Center which we believe can improve the outcome of your cycle.

 

 

DAY MINUS ZERO (-0)
One day before Egg Retrieval

   

 

Daily Quality Control check. Temperatures in the incubators, refrigerators, warm surfaces, and of the room are checked. Culture media pH are also measured. These are all checked to ensure culture environmental conditions are optimal.

    Daily Quality Assurance check. Incubators, refrigerators, laminar flow hoods, centrifuges, microscopes, and all other equipment in the IVF laboratory are checked to make sure they are in good working order.

    Preparation of dishes. Egg retrieval dishes and oocyte insemination dishes are prepared and placed in the incubator for overnight incubation to attain their desired pH and temperature.

    Warming of media. Additional media for sperm preparation and for flushing and washing the follicles are also prepared.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     Pre-Equilibration of Culture Media
      •     Pre-Equilibration of Oil Overlay Solution
      •     Detoxification of Test Tubes and Petri Dishes

 

 

DAY ZERO (0)
Day of Egg Retrieval

  

 

Oocyte Identification and Isolation: When physicians perform egg retrieval, the contents of 1 or more follicles are aspirated into a test tube. The test tube containing follicular fluids collected from the patient's ovaries in the operating room are handed to the laboratory. The follicular fluids are poured into a petri dish and the search for eggs commence. The contents of the follicular fluid aspirate include red blood cells, blood clots, granulosa cells, pieces of cumulus cells, and oocytes/eggs. Most eggs are surrounded by a large matrix of cumulus cells and they are called cumulus-oocyte complex. Cumulus cells are referred to as such because they look similar to cumulus clouds and have a very distinct looking "egg white" translucent appearance making them stand out from the rest of the follicular fluid contents making them easier to identify. On some occasions, the amount of cumulus cells surrounding the eggs can vary from moderate, to barely there, to none at all (eggs with very scanty to absence of cumulus cells are very difficult to locate and identify due to very small size).

    Oocyte Processing: For traditional IVF insemination, the cumulus cells covering and surrounding the eggs are left intact because they assist in further oocyte maturation and in sperm activation (sometimes the cumulus cells are trimmed if they are very bulky).

    Oocyte Preparation for Egg Freezing or ICSI: For Egg Freezing patients and for patients requiring assisted fertilization called ICSI (Intra-Cytoplasmic Sperm Injection) because of male factor issue or genetic testing of embryos are to be done, oocyte preparation requires removing (we call this process oocyte denudation) all the cells surrounding the eggs by exposing the cumulus-oocyte complex to an enzyme and passing the eggs to a very small glass pipet to physically remove the cells surrounding them.

    EGG FREEZING: Viable eggs can be mature (m2, metaphase 2 stage), immature (m1, metaphase 1 stage), or severely immature (gv, germinal vesicle stage). Non-viable eggs are those that are atretic, degenerative, empty zona, and giant-sized diploid eggs. For patients undergoing egg freezing, the mature (m2) eggs are frozen using vitrification technique.

    Sperm Preparation: Traditional sperm preparation methods are the wash-and-swim-up technique or the density-gradient technique. Both entail centrifugation steps.

    Oocyte Insemination: Traditional IVF Insemination involves combining 50,000 motile sperm cells to each egg.

    ICSI: Classic, traditional ICSI.

    Media Preparation: Preparation of embryo culture dishes to be used the next day for further culture of fertilized eggs.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     No Stress Egg and Embryo Handling
      •     No Eggs Left Behind
      •     Non-Toxic Labeling
      •     No Stress Egg Maturity Assessment
      •     FREEZE ALL VIABLE EGGS
      •     No Stress Sperm Isolation
      •     Motile Sperm Morphology
      •     Sperm X or Y Enrichment
      •     Algorithm IVF Insemination
      •     Low Stress ICSI
      •     High Resolution ICSI
      •     Testicular Tissue Sperm ICSI
      •     In-Vitro Maturation (IVM) of Immature Eggs
      •     On Your Eggs' Schedule
      •     Purified Environment Culture System

 

 

DAY 1
2PN Stage (Zygote)

  

 

Fert Check: Examine eggs for signs of fertilization

    Media Changeover: Fertilized eggs are placed in fresh embryo culture media.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     No Stress IVF Chamber Handling of Zygotes (fertilized eggs are called zygotes).
      •     EGG FREEZING OF IN-VITRO MATURED EGGS.
      •     Low Stress High-Resolution ICSI of IVM Eggs.
      •     Rescue ICSI of Non-Fertilized Eggs.
      •     Purified Environment Culture System.
      •     Multi-Source Culture Media.

 

 

DAY 2
2 to 4-Cell Stage Embryos

  

 

No Activity: Most IVF centers do not check embryos on Day 2 but some do Embryo Grading and examine zygotes for signs of further development (cell division) into embryos.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     No Stress IVF Chamber Handling of Embryos (zygotes that undergo cell division are called embryos).
      •     Check for Fertilization of IVM Eggs and Rescue ICSI Eggs.
      •     Embryo Grading to check quality of cell division and further embryo development.
      •     Embryo Freezing of Day 2 Stage embryos, if requested.

 

 

DAY 3
6 to 8-Cell Stage Embryos

  

 

Embryo Grading: assessment of quality of the embryos and embryos are graded as Grade A for good quality embryos, Grade B for fair quality embryos, Grade C for poor quality embryos and Grade D for very poor quality embryos

    Embryo Freezing: of Day 3 stage embryos

    Assisted Hatching: using Laser

    Embryo Transfer: for certain patients such as those with only one embryo and those with previous failed blastocyst formation

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     EMBRYOPLASTY® - microsurgical removal of fragments from fragmented embryos.
      •     No Stress IVF Chamber Handling.
      •     Media Refresh.
      •     Embryo Biopsy for gender only testing.
      •     Purified Environment Culture System.

 

 

DAY 4
Morula Stage Embryos

  

 

No Activity: Most IVF centers do not check the embryos on Day 4 but some do Embryo Grading and examine embryos for signs of further development.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     EMBRYOPLASTY® of IVM-derived Day 3 embryos.
      •     No Stress IVF Chamber Handling.
      •     Embryo Grading - assessment of quality of the embryos.
      •     EMBRYO FREEZING of Day 3 stage embryos derived from in-vitro matured oocytes.
      •     Assisted Hatching of IVM-derived embryos using Laser.
      •     Media Refresh.
      •     Purified Environment Culture System.

 

 

DAY 5
Blastocyst Stage Embryos

  

 

Embryo Grading: assessment of embryos that developed into blastocyst stage.

    Embryo Biopsy for patients undergoing genetic testing.

    EMBRYO FREEZING of only high-quality blastocyst stage embryos.

    Embryo Transfer of blastocyst stage embryos.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     EMBRYO FREEZING of blastocysts including those of fair and good quality.
      •     No Stress IVF Chamber Handling.
      •     Purified Environment Culture System.

 

 

DAY 6
Hatching Blastocyst Stage Embryos

  

 

Embryo Grading: assessment of embryos that developed into blastocyst stage.

    Embryo Biopsy for genetic testing.

    EMBRYO FREEZING of only high-quality blastocyst stage embryos.

    Embryo Transfer of blastocyst stage embryos.

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     EMBRYO FREEZING of blastocysts including those of fair and good quality.
      •     EMBRYO FREEZING of IVM-derived blastocysts.
      •     EMBRYO BIOPSY of IVM-derived blastocysts.
      •     No Stress IVF Chamber Handling.
      •     Purified Environment Culture System.

 

 

DAY 7
Completely Hatched Blastocyst Stage Embryos

  

 

No Activity: Most IVF centers do not culture embryos beyond Day 6, but a few perform Embryo Freezing of high-quality blastocysts on Day 7. 

 

THINGS WE DO DIFFERENTLY AT ROCKEFELLER FERTILITY

      •     No Stress IVF Chamber Handling.
      •     EMBRYO BIOPSY of IVM-derived blastocysts.
      •     EMBRYO FREEZING of IVM-derived blastocysts

 

That's 9 days of activity in the IVF laboratory where your eggs and embryos can spend up to 8 of their first few days.