Frozen embryo transfer (FET)
The thaw-and-transfer cycle that has become the default in US fertility care. Here is what it is, whether it works as well as a fresh transfer, what it actually costs, and the week-by-week timeline.
A frozen embryo transfer thaws an embryo frozen in an earlier cycle and places it in the uterus, separately from the egg retrieval. For most patients it gives a live-birth chance similar to a fresh transfer, and it lowers the risk of ovarian hyperstimulation. A standalone FET typically costs $3,000–$6,900, a fraction of a full stimulated cycle, and a medicated cycle takes about 2–3 weeks of active preparation. Most US embryo transfers are now frozen rather than fresh.
What is a frozen embryo transfer?
The step that actually attempts pregnancy in a modern IVF cycle, run on its own schedule.
In IVF, stimulation and egg retrieval produce embryos in the lab. In a frozen embryo transfer, those embryos are cryopreserved and a single one is thawed and transferred in a later cycle, rather than transferred fresh in the same cycle as the retrieval. An embryo can be frozen for years and thawed when the timing is right, which is what makes a second or third attempt from one retrieval possible without stimulating again.
This is now the default. Most US embryo transfers are frozen rather than fresh, a reversal from a decade ago, because freezing lets the body recover from stimulation before the lining receives an embryo, and modern fast-freezing (vitrification) preserves embryos with very little loss. A "freeze-all" cycle freezes every viable embryo and plans the transfer for a later, unstimulated cycle.
Is a frozen transfer as successful as a fresh one?
For most patients the two are close. The real answer depends on how you respond to stimulation, not on fresh versus frozen alone.
In randomized trials of women who ovulate normally, transferring the first embryo frozen produced live-birth rates similar to a fresh transfer. For the average patient, choosing frozen does not lower the chance of a baby. Source
When ovarian stimulation produces many eggs, freezing every embryo and transferring in a later cycle lowers the risk of ovarian hyperstimulation syndrome (OHSS) and can improve the cumulative chance of a live birth, because the uterine lining is not exposed to high stimulation hormones. Source
Freeze-all is not a universal upgrade. For some low responders a fresh transfer may give an equal or better chance, so the decision is individual to your diagnosis and how you respond to stimulation. Source
Frozen transfers are linked to a lower risk of preterm birth and low birth weight, but a somewhat higher risk of pre-eclampsia and larger-than-average babies. The differences are modest and worth discussing with your clinic. Source
Whichever route you take, the number that moves outcomes most is age. National live-birth rates run from about 49.7% per intended egg retrieval under 35 to 7.7% over 40 (CDC, patients using their own eggs). See the full by-age and per-clinic breakdown, and why a "per transfer" rate looks higher than a per-retrieval one, on our success rates page.
How much does a frozen embryo transfer cost?
An FET is one of the cheapest steps in IVF, because it skips almost everything that makes a full cycle expensive.
In a modern freeze-all protocol this is the step that produces the pregnancy, not an optional extra. Includes roughly $400 to $1,500 in lining medications. An FET is far cheaper than a full stimulated cycle because it skips the stimulation medications (about $5,000), the egg retrieval, anesthesia, and lab fertilization that make up most of the roughly $13,500 base cycle fee. If your embryos are already frozen from an earlier retrieval, the FET is the only cost of that attempt, which is why a freeze-all approach spreads the expense of one retrieval across several affordable transfers.
The frozen embryo transfer timeline
A medicated cycle takes about 2–3 weeks of active preparation, or roughly 4–6 weeks counting suppression. Exact timing depends on your protocol and how the lining responds.
- 1Cycle preparation and suppressionabout 2 to 4 weeks
Birth-control pills or other suppression quiet the ovaries so the transfer can be scheduled precisely, rather than around your natural cycle. Source
- 2Estrogen to build the liningabout 10 to 14 days
Estrogen thickens the uterine lining. A blood test and ultrasound confirm it has reached a receptive thickness (clinics typically look for roughly 7 mm or more) before moving on. Source
- 3Progesterone, then the transfertransfer around day 6 of progesterone
Progesterone prepares the lining to accept an embryo and sets the transfer day. The thawed embryo is placed with a thin catheter in a quick, usually painless procedure that needs no anesthesia. Source
- 4Pregnancy testabout 9 to 11 days after transfer
A blood test measures hCG to confirm pregnancy. Progesterone support usually continues into early pregnancy if the test is positive. Source
A natural-cycle FET skips most of this medication and times the transfer to your own ovulation, which suits patients with regular cycles. A medicated cycle trades more medication for precise scheduling and control.
Common questions about frozen embryo transfer
What is a frozen embryo transfer (FET)?
A frozen embryo transfer is a cycle in which an embryo created and frozen earlier, sometimes years before, is thawed and placed into the uterus. It is decoupled from the egg-retrieval cycle, so the stimulation, retrieval, and lab work happen once and any surplus embryos are cryopreserved for later transfers. Most US embryo transfers are now frozen rather than fresh, a shift from a decade ago when fresh transfers were standard.
Is a frozen embryo transfer as successful as a fresh one?
For most patients, yes: randomized trials in women who ovulate normally found similar live-birth rates whether the first embryo was transferred fresh or frozen. Freezing every embryo (a freeze-all cycle) lowers the risk of ovarian hyperstimulation and can improve outcomes for high responders, while for some low responders a fresh transfer may do as well or better. Success depends far more on age and diagnosis than on fresh versus frozen, so the choice is individual to your response to stimulation.
How much does a frozen embryo transfer cost?
A standalone frozen embryo transfer typically costs about $3,000 to $6,900, including roughly $400 to $1,500 in lining medications. That is a fraction of a full stimulated cycle, because an FET skips the stimulation medications (about $5,000), the egg retrieval, anesthesia, and lab fertilization that make up most of the roughly $13,500 base cycle fee. If your embryos are already frozen, the FET is the only cost of that attempt.
How long does a frozen embryo transfer take?
A medicated FET cycle takes about 2 to 3 weeks of active preparation, or roughly 4 to 6 weeks counting the suppression phase. Estrogen builds the uterine lining for about 10 to 14 days, then progesterone starts and the thawed embryo is transferred around the sixth day of progesterone. A pregnancy blood test follows about 9 to 11 days after transfer. A natural-cycle FET uses far less medication and times the transfer to your own ovulation.
Why do most clinics freeze embryos now instead of a fresh transfer?
Because freezing lets the body recover from stimulation before the transfer, so the uterine lining is not exposed to high stimulation hormones, and because modern vitrification (fast-freezing) preserves embryos with very little loss. Freeze-all also removes the risk of ovarian hyperstimulation syndrome from a fresh transfer and lets clinics test embryos genetically before transferring. For most patients the live-birth chance is similar either way, which is why frozen has become the default.
Work out your real number
The full itemized cycle: base fees, real medication prices, and every add-on that lands on the bill.
National live-birth rates by age from CDC data, plus per-clinic rates and what the denominators mean.
The states that mandate IVF coverage, the loophole that denies it anyway, and how to check your own plan.