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Top 5 Embryology Questions, Answered by an Expert

An embryologist tackles common questions, like why we store abnormal embryos, how long embryos last, and other FAQs!

July 19th, 2023 | 6 min. read

By Sierra Dehmler

The world of embryology is both fascinating and mindblowing, leaving many fertility patients wondering how it all happens. The life-changing work that embryologists do each day make amazing things like IVF possible - and now, they're answering your top embryology questions!

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What is an embryologist?

Within the fertility treatment process, embryologists are the people that care for the egg, the sperm, and ultimately, the embryo. They meticulously analyze and watch over the future of someone’s family. As Erica Paganetti puts it, "Embryologists are your child’s first babysitter!”

Erica Paganetti is Illume Fertility’s Senior Embryologist and Embryology Lab Manager. She leads a dedicated team of embryologists, lab technicians and other staff as they foster the early development of embryos - including monitoring, grading, testing, and freezing them.

During the freezing process, also known as cryopreservation, an embryologist is responsible for making sure your embryos, eggs, or sperm are carefully stored for as long as you need.

Top 5 Embryology Questions 

The field of embryology is full of incredibly complex processes and terminology, which can make it feel, well - a bit mysterious. So, what are embryologists really doing in those dark IVF labs? Is freezing embryos for years and years actually safe? 

Below, Erica answers the top five most frequently asked questions she and her team receive, particularly concerning cryopreservation and embryos created in the IVF process.

1. My embryo was abnormal…why did you still freeze it?

Embryos are cultured in our laboratory for a maximum of seven days. For patients who opt to do preimplantation genetic testing (PGT), their embryos are carefully biopsied, then cryopreserved while we wait for results from an outside genetics lab.

Cryopreservation allows us to suspend the development of the embryos until you are ready to use them. The samples collected from each embryo are loaded individually, labeled, and shipped to a genetic testing facility for processing.

So, the short answer is this: We don’t know for sure if the embryos are abnormal or not when we first freeze them, so we have to wait for the genetic testing results to find out.

Genetic testing results have a turnaround time of about two weeks. In the meantime, we freeze all of the embryos in the hopes of normal preimplantation genetic testing (PGT) results.

2. How do you grade embryos? What do embryo grades mean?

Before we send samples out for genetic testing and cryopreserve your embryos, we analyze each one using a very complex grading process. The grade we assign is an overall assessment of each embryo’s developmental stage and quality.

There can be significant variation in embryo grading, even within a single patient’s group of embryos. We utilize the grade as an indicator of embryo quality, aiding us in selection of the best embryo for procedures such as embryo transfer, cryopreservation, and/or biopsy.

Embryos eligible for these procedures fall within a range of grading criteria specific to our lab. Although there are a range of grades within embryos that can be transferred, cryopreserved, or biopsied, all of these embryos have significant reproductive potential. Note:

Note: Even if you have a lower-graded embryo, it doesn't always mean that it won't result in a successful pregnancy and healthy baby! Your Care Team will be able to offer guidance and help answer any questions you have about embryo grading.  

3. How long does it take for samples from another facility to be transferred?

When a patient comes to us from another facility, with oocytes (eggs), sperm, and/or embryos in storage, they often request the transfer-in of these specimens.

We must collect all records related to these samples, which include analysis reports, culture information, cryopreservation and warming protocols, infectious disease testing, and other important information.

Once we receive all the required paperwork, your records are reviewed for approval, and the transport of your eggs, embryos, or sperm can be scheduled. From start to finish, this process generally takes about 3-6 weeks.

Is IVF right for you?

Download our free step-by-step guide to IVF to learn how much it costs, how long the process typically takes, and how this treatment method can help make your dreams come true. 

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4. How long do frozen embryos last?

Cryopreservation suspends (or halts) embryo development indefinitely. Frozen embryos have no known expiration date and can be used at any point in the future.

The current world record for the "oldest" embryo used resulting in a successful pregnancy was frozen for 30 years before being thawed and transferred! How incredible is that?

Twins Lydia and Timothy Ridgeway set this new record after their birth in October 2022. The previous record-holder, Molly Gibson, was born in 2020 from an embryo that had been frozen for nearly 27 years.

Stories like these are living proof that cryopreserved embryos can be successfully utilized for many, many years after their creation - longer than some ever imagined. 

5. If you used frozen sperm for my IUI/IVF procedure, why am I still receiving a storage bill?

Cryopreserved semen samples are generally processed and stored in multiple vials for future use. Even if you have multiple vials available for use, when thawing vials of sperm for IUI and/or IVF, vials are warmed and processed one at a time. Additional vials are only thawed when absolutely necessary.

This usually results in additional samples remaining in storage, so please be aware that fees will usually still apply, even after your cycle is complete. Ask your Care Team if you have any questions about your specific storage plan.

Did you learn something new?

We hope so! If you have additional questions about IVF or embryology, send us a message or submit it for consideration in our Ask Monica Q&A video series.

A big thank you to our Senior Embryologist and Lab Manager Erica Paganetti for answering these important questions and providing a little peek inside the incredible world of embryology. 

Sierra Dehmler

Sierra Dehmler is Illume Fertility’s Content Marketing Manager - and also a fertility patient herself. Combining empathy gained on her personal journey with her professional experience in marketing and content creation, she aims to empower and support other fertility patients by demystifying the fertility treatment process.

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