An embryo transfer is the final step of in vitro fertilization (IVF), following stimulation of the ovaries, egg retrieval, and fertilization.
A fresh transfer is typically performed within a week of the egg retrieval, as a fresh embryo can only survive for five to six days. The timeline is significantly more flexible with a frozen embryo transfer, with frozen embryos remaining viable for at least 10 years. Let’s take a closer look at this process.
Fresh vs. Frozen Embryo Transfer
The medical procedure itself is the same for both fresh and frozen embryo transfers, but a frozen embryo transfer typically involves additional fertility medications. Here are both processes at a glance.
Fresh Embryo Transfer
Ovarian stimulation medications
Trigger medication
Egg retrieval
Fertilization
Potentially 1-2 days of hormonal fertility medications (progesterone and/or estrogen) that thicken the lining of the uterus to support successful embryo implantation
Embryo transfer
Two-week waiting period before a pregnancy test
Pregnancy test
Up to 12 weeks of progesterone and/or estrogen to support a healthy pregnancy
Frozen Embryo Transfer
Ovarian stimulation medications
Trigger medication
Egg retrieval
Fertilization
Embryo is frozen and stored for later use
Embryo transfer planned - several weeks of hormonal fertility medications (leuprolide, progesterone, and/or estrogen) that thicken the lining of the uterus to support successful embryo implantation
Embryo transfer
Leuprolide use ends
Two-week waiting period before a pregnancy test
Pregnancy test
Up to 12 weeks of progesterone and/or estrogen to support a healthy pregnancy
The purpose of leuprolide, estrogen, and progesterone in a frozen embryo transfer is to recreate ideal hormonal conditions in the body for implantation. Leuprolide temporarily pauses the body’s natural hormone production so that the supplemental progesterone and/or estrogen can achieve their desired results.
In a fresh transfer, there isn’t as much time to prepare the body with these hormonal medications. You are relying primarily on natural hormone production to bring your body into the ideal state for pregnancy, but some people may take estrogen and/or progesterone for several days before the transfer.
Estrogen and progesterone are used as pregnancy support medications in both fresh and frozen transfers for up to 12 weeks. In either process, if the transfer isn’t successful, you must wait at least a month before attempting another transfer, so that your body can recover.
You may be familiar with leuprolide as a trigger medication. In FET, the same medication is used very differently. Here, it is injected at a very small dose daily for several weeks.
The benefits of a frozen embryo transfer
Frozen transfers are more common than fresh ones given the small window of viability for fresh embryos. The more flexible timing of a frozen embryo transfer offers several benefits:
More flexibility in planning your family building journey
More time for your body to recover after ovarian stimulation and trigger medications - this is especially important if you experienced a health complication such as ovarian hyperstimulation syndrome (OHSS) during IVF
Time for genetic testing of embryos
Time to take the combination of leuprolide and progesterone and/or estrogen, which allows your doctor to create ideal conditions for embryo implantation
Additionally, through a frozen embryo transfer, you can attempt to conceive more than once with embryos retrieved from a single IVF cycle. This means you don’t have to repeat the intensive protocol of stimulation medications.
Preparing for embryo transfer
Be sure to prioritize sleep as you prepare for FET — your mind and body need plenty of rest before and after the procedure.
It is important to arrive at your clinic with a full bladder. This makes your uterus more visible and accessible during the procedure. Your care team will advise you more specifically, but it is typically recommended to drink about 16-20 ounces of water.
An embryo transfer is less invasive than egg retrieval, and anesthesia typically is not required. If you are not undergoing anesthesia, there won’t be restrictions around eating or drinking the night before. You can also drive yourself to and from the clinic if you are comfortable doing so. If your doctor recommends anesthesia, check with your care team about additional instructions and requirements.
Your doctor will offer more specific guidance of what to do and not to do after FET, but it is typically advised to avoid strenuous exercise as well as extreme temperatures against your abdomen and uterus.
You will return to the clinic approximately two weeks after embryo transfer for a blood test that measures your levels of hCG (human chorionic gonadotropin) to determine if the embryo transfer has resulted in a pregnancy. Stress and anxiety are natural during this waiting period, so plan ahead to make sure you have what you need to take care of yourself physically and mentally.
Choose the right fertility pharmacy
Fertility treatment can be challenging, but Alto is with you every step of the way. We offer reliable same-day delivery of your medications and fertility resources like personalized injection guide videos and access to fertility-trained pharmacists.
Interested in learning more about how Alto can support your treatment? Request a price quote online or reach out through secure in-app messaging.
This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition.
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