Frozen Embryo Transfer Timeline: What to Expect Step by Step
A frozen embryo transfer (FET) is a common part of the IVF process for many people. And it’s essential for those who already have embryos from a previous cycle or have opted for genetic testing, egg/embryo banking, or delayed transfer for medical reasons.
While the procedure itself takes only 5-15 minutes, there is a carefully timed preparation phase to help the uterus become ready for implantation.
Understanding the frozen embryo transfer timeline can help you feel more prepared and confident as you enter this stage of your treatment.
In this guide, we’ll break down the timeline of a typical medicated FET cycle and what to expect from start to finish.
Why Timing Matters in a Frozen Embryo Transfer Cycle
Unlike an IVF cycle with a fresh transfer, a frozen transfer separates ovarian stimulation and egg retrieval from embryo implantation.
The time in between allows the body time to recover and gives your clinical team more control over your hormonal environment.
The goal of a medicated FET timeline is to:
• Build an optimal uterine lining
• Synchronize progesterone levels with the embryo’s development
• Support early implantation and pregnancy
Because timing is critical, most steps are carefully monitored through ultrasound and bloodwork.
Medications Used During a Medicated FET Cycle
Two hormones play the largest role in preparing for a frozen embryo transfer.
Estrogen
Estrogen is used to thicken and stabilize the uterine lining. It may be prescribed as:
• Oral tablets
• Vaginal tablets
• Estrogen patches
Most patients begin estrogen on day 2–4 of their menstrual cycle.
Progesterone
Progesterone is the hormone that prepares the uterine lining for implantation of the embryo. It may be prescribed as vaginal suppositories, oral progesterone, or intramuscular progesterone in oil.
Progesterone timing is based on the developmental stage of the embryo:
• Cleavage-stage embryos: Progesterone usually begins three days before transfer.
• Blastocyst-stage embryos: Progesterone typically begins five days before transfer.
Your care team will personalize these details based on the embryo/s you are transferring, your medical history, and your treatment plan.
Frozen Embryo Transfer Timeline at a Glance
| Phase | Approximate Timing | What Happens | Medications |
|---|---|---|---|
| Cycle start and estrogen begins | Day 1–2 of menstrual cycle (estrogen is usually started around cycle day 2–4) | Your period begins and the FET cycle starts. Estrogen is started early in the cycle to help thicken and prepare the uterine lining. | Estrogen taken orally, vaginally, or via patches |
| Lining monitoring | Day 10–14 | Ultrasound and bloodwork check the thickness and appearance of the uterine lining and confirm hormone levels are appropriate. | Estrogen continues as directed |
| Progesterone start | 3–5 days before transfer, depending on embryo stage | Progesterone is started to make the uterine lining receptive to the embryo. Typically three days before a cleavage-stage transfer or five days before a blastocyst transfer. | Progesterone as vaginal suppositories, oral pills, or intramuscular injections (progesterone in oil) |
| Transfer day | Scheduled based on progesterone timing | The frozen embryo is thawed and gently placed into the uterus during the transfer procedure. | Estrogen and progesterone continue |
| After transfer | Luteal phase and into early pregnancy | Progesterone continues after transfer to support implantation and early pregnancy. Estrogen usually continues as well, per clinic protocol. | Progesterone and estrogen continue as directed |
| When to stop progesterone | Typically between 8 and 12 weeks of pregnancy (per clinic protocol) | Most clinics recommend continuing progesterone until the placenta takes over hormone production, usually around 8–12 weeks. Stopping too early may compromise support, while continuing longer generally poses no harm. | Progesterone gradually discontinued when your provider advises |
While every patient’s plan may look slightly different, a typical medicated FET timeline includes the following phases.
Day 1–2 of Menstrual Cycle
Estrogen begins shortly after your period starts. This marks the beginning of the preparation phase.
Day 10–14
You will attend monitoring appointments to measure lining thickness via ultrasound and check hormone levels through bloodwork. Many clinics aim for an endometrial lining measurement of around 7–10 millimeters, though exact criteria vary.
Adjustments to estrogen may be made during this time.
3–5 Days Before Transfer
Progesterone is added based on the age of the embryo being transferred. This shift marks the start of synchronization between the body and embryo.
Transfer Day
The frozen embryo is carefully thawed, assessed, and transferred into the uterus. The procedure is typically brief and does not require anesthesia for most patients.
After Transfer
Progesterone and estrogen continue through the luteal phase and, if pregnancy occurs, into the early first trimester to maintain a supportive hormonal environment for implantation and embryo development.
When Can You Test for Pregnancy?
Most patients take a blood pregnancy test 9–12 days after transfer, depending on embryo type and clinic protocol. While home pregnancy tests are tempting, bloodwork provides the most accurate and reliable result.
When to Stop Progesterone After Frozen Embryo Transfer
A common question many patients have is how long progesterone support continues after a successful transfer.
Most clinics recommend continuing progesterone until the placenta can produce adequate levels of hormones independently.
This transition typically occurs between 8 and 12 weeks of pregnancy.
The exact timeline depends on clinic protocol and individual factors, so it is essential to follow your provider’s instructions.
Stopping progesterone too early may increase the risk of hormonal disruption, while continuing slightly longer than necessary generally poses no harm.
How Long Does the Entire FET Process Take?
From the start of your menstrual cycle to embryo transfer, the typical medicated FET process lasts about three to five weeks.
If additional time is needed to improve lining thickness or regulate hormones, the timeline may be extended.
FET Timeline: The Takeaway
A frozen embryo transfer is carefully timed to give implantation the best possible chance.
While there are several steps leading up to the transfer, many patients appreciate that an FET cycle is often less intensive than a fresh IVF cycle and provides more flexibility in timing.
Working closely with your fertility team and following medication instructions helps ensure the uterine environment is properly prepared for a healthy embryo transfer and early pregnancy.
If you have questions about your frozen embryo transfer timeline or want to explore affordable FET options, schedule a consultation with the team at CNY Fertility.
