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Embryo Grading

The following is a guide on how RADfertility’s IVF lab assesses blastocyst embryos utilizing the grading scale created by Dr. David K. Gardner.

The embryo grading process assesses embryo quality and requires a vast amount of training and skill. Our embryologists use their experience to grade the embryos and select the best embryo for transfer. Please keep in mind that regardless of the grade, we only freeze and transfer embryos that we believe have a chance of resulting in a successful pregnancy.

Once fertilized, embryos will continue to develop in our laboratory for up to seven days. A blastocyst is the most advanced stage an embryo can achieve in culture and typically occurs 5 – 7 days post-fertilization. Only the best quality embryos develop to the blastocyst stage. A blastocyst has two distinct cell types and a central cavity filled with fluid:

Number Describing Overall Expansion of the Fluid Cavity

Initially blastocysts are given a numerical score from 1 to 6 based upon their degree of expansion and hatching status. This part of the assessment can be performed on a dissection microscope.

1 – Early Blastocyst

Blastocoel < half the volume of the embryo

2 – Blastocyst

Blastocoel > half the volume of the embryo

3 – Full Blastocyst

Blastocoel completely fills the embryo

4 – Expanded Blastocyst

Blastocoel volume is now larger than that of the early embryo and the zona is thinning

5 – Hatching

Embryo has breached the zona pellucida and is hatching out of its shell

6 – Hatched

Embryo is completely hatched

Letter Grade for Inner Cell Mass

The second step in scoring the blastocysts should be performed on an inverted microscope. The development of the inner cell mass (ICM) can then be assessed. The ICM is given a letter, the highest score being an A.

Letter Grade for Trophectoderm

The third step in scoring the blastocysts should be performed on an inverted microscope. The development of the trophectoderm can then be assessed. The trophecoderm is given a letter, the highest score being an A.

Additional Embryo Assessment Tools


Embryo grading is much more than the embryos’ isolated appearance. It also includes their morphokinetic development as witnessed via the EmbryoScope+.

Learn more about the EmbryoScope+

Preimplantation Genetic Testing For Aneuploidies (PGT-A, Formerly Known As PGS)

The chromosomal status of an embryo can be determined with preimplantation genetic screening which evaluates all 46 chromosomes within a few cells carefully removed from each embryo. PGT-A provides information regarding the chromosomal health of the embryo.

Learn more about Preimplantation Genetic Testing For Aneuploidies (PGT-A)

IVF For ME (Maximal Efficiency)

EmbryoScope+ time-lapse technology, when used in combination with PGT-A is a powerful tool in the decision-making process. This is why our IVF For ME program includes PGT-A and the use of EmbryoScope+ to monitor embryo development from its first cells.

Learn more about our IVF For ME program.

About Our Laboratory

Our laboratory team leads the way through research and innovation contributing to nationally recognized success rates.

Embryo Grading

RADfertility uses the grading scale created by Dr. David K. Gardner to assess blastocyst embryos.


Time-lapse technology enables RADfertility's IVF experts and patients to view embryo development from its first cells.


Preimplantation genetic testing for aneuploidies (PGT-A) is a tool used to optimize the efficiency of IVF, increasing the likelihood of a successful pregnancy.


Preimplantation genetic testing for monogenic/single gene defects (PGT-M) and (PGT-SR) are tests that help evaluate embryos for genetic risk factors.

Semen Analysis

A semen analysis is performed in order to assess the viability of sperm before treatment at RADfertility.

RADdad at-Home Sperm Collection Kit

Our RADdad at-home sperm collection kit provides a convenient and discreet alternative to the fertility center setting.

Peggy Sue O.


"I feel so lucky to have found RADfertility. I tried two other clinics before I expanded my search and found RADfertility. I drive an hour each way to go to them but I don’t regret a thing. They are so caring and so professional. Every time I message them they respond quickly. Every time I see them they have a friendly smile and warm welcome. They explain everything so well and I never feel lost in the process as I did elsewhere. They also took the time to figure out what was wrong. Other clinics threw up their hands, said 'I don’t know' and pushed me to try IVF."



"Dr. Feinberg and the entire staff at RADfertility are absolutely amazing. The receptionists, coordinators, nurses, and lab staff are compassionate, caring, and straight forward. I’ve had a 12-year infertility journey and I’ve tried other clinics but RADfertility was the only one I felt at ease with. They answered any questions that I had and were there any time I needed them. My coordinator, Amy, was the absolute best and always had my back. Dr. Feinberg’s dedication to his patients is incredible. You are not just a number there, you are a person with individualized needs and care."

Anupama P.


"The RADfertility team gives you so much emotional support and positivity that it adds to your strength and keeps you focused on the end goal - a healthy and happy baby."

Samantha G.


"My journey with RADfertility and Dr. McGuirk started when my husband and I were trying to conceive and were having difficulty. We went to RADfertility, where we met Dr. McGuirk. I always say she changed my life and 'fixed' me. Dr. McGuirk is always learning more about endometriosis and how to help her patients. She’s brilliant and truly cares for you! I’m eternally grateful to her and everyone at RADfertility for their unwavering support, love, and care."

Annette D.


"Every step of our journey was tailored to us. We were treated so respectfully. Every detail was clearly explained and we felt so comfortable. Rhonda Wright was a Godsend and inspiring. I highly recommend this place! I cried when my weekly appointments were done and I 'graduated.'"

Christie B.


"The staff and doctors are amazing. It will feel like home every time you walk in the door. They gifted us with our miracle baby and we couldn’t be happier. I will always recommend RADfertility above all others!"

Shannon M.


"RADfertility's staff has heart and provided me with exceptional health care. I knew I was in good hands and felt like we were in this together. The doctors and nursing staff always answered all of my questions and provided thorough information about all of my options. I am so fortunate and appreciative of the care that I received at RADfertility. They go above and beyond."

Megan L.


"I cannot begin to explain how wonderful RADfertility is. We were frustrated with trying to start a family and it not working for us. The entire team of doctors and nurses made us feel comfortable and hopeful that we would be parents. We experienced so many ups and downs but we never felt like we were on our IVF journey alone, we had our RADfertility team every step of the way. If you're looking for a supportive team on the IVF journey, look no further. RADfertility is the absolute best."

Anonymous on FertilityIQ


"Dr. Schillings always kept us informed and never gave up on us. She always explained our options and risks with each procedure. She called us personally when there were any issues or sensitive subjects to cover. Dr. Schillings was the first doctor that had answers for us and wanted to help us have our miracle baby!"

Newark Office

4735 Ogletown-Stanton Road
MAP 2, Suite 3217
Newark, DE 19713

Wilmington Office

Silverside Medical Center
2700 Silverside Road, Suite 2A
Wilmington, DE 19810

Dover Office

Eden Hill Medical Center
200 Banning Street, Suite 240
Dover, DE 19904


Phone: (302) 602-8822

Fax: (302) 602-8832

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