How Embryologists in IVF Labs Prepare for Your Embryo Transfer Day
Embryo transfer is one of the most crucial steps in an in vitro fertilization (IVF) cycle. While much of the focus is on the patient’s preparation, behind the scenes, embryologists play a vital role in ensuring that everything is set for a successful transfer. These highly trained specialists handle embryos with extreme care, optimizing their chances of implantation. But what exactly happens in an IVF lab before your embryo transfer? Let’s take a closer look at how embryologists prepare for this big day.
1. Selecting the Best Embryo for Transfer
Embryologists begin preparation by carefully evaluating the embryos created during fertilization. If multiple embryos are available, they will assess them based on morphology (appearance), growth rate, and cell division patterns. This evaluation helps them determine which embryo has the highest potential for implantation.
Many patients ask about “embryo grade” or embryo quality”. Essentially this is a metric that embryologist use to assess the quality of an embryo. Many labs may have their own metric system, but the most common method is the Gardner Method of grading. This simply gives embryos a grade based on how they look. Ironically, this has no way shape or form of describing the health of an embryo. The prettiest embryos could actually be genetically abnormal compared to the ugliest embryo, so this is where genetic testing comes in.
For patients who have undergone preimplantation genetic testing (PGT), embryologists also review genetic screening results to ensure the embryo selected is chromosomally normal, further increasing the chances of a healthy pregnancy. This is the single most important criteria because an normal embryo will 100% perform better than an abnormal embryo. If a poorly graded embryo is genetically normal (euploid), then it will most certainly be selected for transfer over the highest graded embryo that is genetically abnormal (aneuploid). Genetic testing is truly a time saving technology because it can save patient’s time and effort from transferring an abnormal embryo.
With that being said, all embryos should be selected 1-7 days before the actual transfer date so that the lab has the time to prepare all documents and media before the embryo transfer day.
2. Thawing Frozen Embryos (If Needed)
If the transfer is a frozen embryo transfer (FET), embryologists must carefully thaw the embryo before transfer. This process, known as vitrification and warming, requires precise timing and handling to ensure embryo survival. With modern freezing techniques, embryos have an excellent 95%+ survival rate after thawing. Embryologists monitor the embryo closely during this process to confirm it remains intact and healthy.
Thawing the embryos typically occurs 2 hours before embryo transfer. This is actually pretty much the gold standard for all labs in America. Surprisingly, studies have been done that counteract this ideology, but labs continue to follow this timeframe because they believe it gives the embryo an opportunity to recover and re-equilibrate from vitrification before embryo implantation. Whether it’s been found to be superstitious, it certainly doesn’t hurt! Check out this paper on post-warming times before transfer. The results may surprise you!
3. Ensuring the Right Culture Conditions
Embryos are stored in highly controlled incubators that mimic the conditions of the human uterus. These incubators maintain precise temperature, humidity, and gas levels to keep embryos in an optimal state before transfer. On transfer day, embryologists confirm that the incubator settings are stable and that the embryo is in its best possible condition.
4. Preparing the Embryo Transfer Catheter
Once the embryo is ready, embryologists load it into a specialized catheter—a thin, soft tube that will be used by the fertility doctor for transfer into the uterus. The catheter is filled with a small amount of culture medium to help facilitate smooth transfer.
Embryologists also work closely with the doctor performing the procedure to ensure the catheter is properly loaded and the embryo is in the correct placement for transfer.
Actually we’re all working together including the patient! Everyone is awake during this painless procedure and there’s typically a screen so the patient can see where the embryo gets dropped off!
5. Final Quality Checks and Communication with the Medical Team
Before the transfer, embryologists double-check all patient and embryo details to ensure the correct embryo is being transferred to the right patient. This is a critical step to prevent any errors and ensure accuracy. They also communicate closely with the fertility doctor, confirming that the embryo is healthy and ready for implantation.
Strangely, this step is highly regulated in the compliance agencies, yet mistakes still happen! Most patients are too nervous to actually be double checking anything so the IVF Kitchen recommends focusing on this double check process before the transfer starts.
Conclusion
Embryologists play a vital role in the IVF process, ensuring that embryos are carefully handled, selected, and prepared for transfer. Their expertise in maintaining the best possible conditions for the embryo can make all the difference in achieving a successful pregnancy. While patients focus on their own preparation, they can rest assured that behind the scenes, a dedicated team of embryologists is working meticulously to optimize their chances of success.
“Your embryo’s big day is like a VIP concert. The embryologist is security, the uterus is the venue, and the embryo is the star performer about to take the stage!”
