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An Embryologist’s Day: Timers, Dishes, and Embryos

Anna Park is a senior embryologist at Pacific Northwest Fertility in Seattle. She saw her first human egg fifteen years ago and has been hooked on the science and mystery of fertility ever since!

Some things go together like sperm and eggs. The words “careful” and “embryologist”, for example.

An Embryologist’s Day

Not a embryologist’s day goes by when I’m not checking my grip on a stack of dishes bound for the incubator, or watching my feet as I maneuver around a chair while holding a dish of eggs. Embryos are a culmination of time and effort and expense (not to mention hopes and dreams!) and I’m not letting anything happen to the cells in my care.

An embryologist’s day is punctuated by the beeping of timers. Our ears are attuned to the sound because most of the work we do in the lab requires careful timing: How long an embryo spends in warming media, how quickly an egg is loaded onto a cryo straw, when a semen sample is ready to be processed. The most important timer of all is silent and resides in the embryo itself. Starting at egg retrieval, our daily workflow is set to match the timing of embryo development. Which means we embryologists have to be on time and fully staffed every day of the week. An embryo’s internal timeclock stops for no one!

Actually, only a small portion of an embryologist’s day is spent handling embryos. The rest of the time we’re checking the gas levels of the incubators, ordering and testing supplies, entering charts, and preparing dishes and media for embryo culture. Oh, and maybe a lunch break or an afternoon coffee. We are only human. Embryos may run on protein and glucose, but this embryologist, is fueled by caffeine.

Aspects of Embryology

One of my favorite aspects of embryology is how it exists at the crux of science and patient care. I enjoy meeting our patients, telling them about their embryos, being present at the point of the fertility journey when an embryo is transferred into the uterus. Some patients have success right away and before I know it, they are back in the clinic ready to add to their family. For others, pregnancy is more elusive. These are the patients I get to know a bit better, that recognize me when I come in the room and greet me by name. I always hope that when I step into the transfer room with a smile on my face and a picture of the embryo, my presence is familiar and reassuring and not a reminder of past disappointment.

The other side of the equation is the work that occurs in our clean, high tech lab. I love the quiet moments of concentration while sitting at the microscope. Working with embryos takes a lot of focus, and at times I’m still struck by how amazing and beautiful they are. On some afternoons, when the day’s work is done and the only sound in the lab is the rushing whoosh of air filters, I think of the embryos safe and sound in the incubators, their cells silently dividing and organizing.


Embryology is a unique profession and not a skill set that can be learned in a lecture hall. Today, more and more academic programs are addressing reproductive technology, but the majority of us were trained on the job in the laboratory setting. An educational background in science is a common denominator for embryologists, followed by years of hands on training.

I found one of the most challenging skills was learning how to immobilize and pick up a single sperm. Sperm are so tiny! And they zip and zig-zag around. I kept a photo of the first egg I ever fertilized on my refrigerator for months. I felt so proud! How amazing that the day before it had been a sperm and an egg and now here was a single cell containing the DNA of two separate individuals. I remember waiting nervously for ten days after the first embryo transfer I assisted with, and was overjoyed when the patient had a positive pregnancy test.

New Technology

The technology we use in the IVF lab continues to evolve and improve. When I first started out in the field, egg freezing was experimental and had poor success rates. Now, with the advent of Vitrification, we regularly bank eggs for patients wishing to extend their window of fertility.

Chromosomal screening has also become a common part of embryology and further increases our ability to choose an embryo most likely to cause a successful pregnancy. I’m excited to always have a “what’s next” in embryology and the chance to keep learning more and more about individual embryos and how to keep them happy and stress free during their stay in my lab.

But for now, if you’ll excuse me, I have to run. I hear I timer going off…