You still have stimulation and egg retrieval, but there is no fresh transfer a few days later. If you expected a transfer straight away, ask your team two things: why the plan changed, and what needs to happen before you can move ahead.
The warning signs, including when to call 911, are listed at the end of this page.
What is a freeze-all cycle?
In a standard IVF cycle, an embryo is placed in the uterus a few days after retrieval, and any extra embryos may be frozen. This is called a fresh transfer.
In a freeze-all cycle, all embryos suitable for freezing are frozen instead. One is thawed and placed in your uterus in a later cycle, when your ovaries are no longer being stimulated. You may also hear it called "freeze-only" or "elective frozen embryo transfer."
Why might my clinic freeze all embryos?
Ask your doctor which of these reasons applies to you, because it affects what you are waiting for.
- Lowering the risk of OHSS. Ovarian hyperstimulation syndrome (OHSS) is an overreaction to fertility drugs, and pregnancy can make it more severe. Freezing all embryos lowers the risk of moderate or severe OHSS, but it does not remove it. Early OHSS can start 4 to 7 days after an hCG trigger, with or without a transfer. A Cochrane review estimated that if 3% of people got OHSS with a fresh transfer, about 1% would with freeze-all.
- Waiting for PGT-A results. PGT-A checks embryos for too few or too many chromosomes. If you choose it, the lab removes a few cells from each suitable embryo and sends them for testing. The embryos must stay frozen while the testing takes place. Freezing makes time for testing, but that is not the same as a proven benefit. ASRM says the value of PGT-A as a routine test for everyone having IVF has not been shown.
- High progesterone at the end of stimulation. Some studies found this can make implantation less likely in a fresh transfer. It seems to affect the lining of the uterus, not the eggs.
- Embryos and lining out of step. If embryos grow more slowly, the lining may be ahead of them. A later transfer can bring the two back in step.
- Stimulation plans that need it. Some newer stimulation plans leave the lining out of phase for a transfer in the same cycle.
Is freeze-all the right choice for me?
Freezing all embryos is not the best choice for everyone. The reason for freezing, how you responded to stimulation and how many embryos you have all matter, so research averages may not fit your case.
Across many groups: A Cochrane review found little or no difference in the overall chance of a live birth when it compared freeze-all with a fresh transfer first. Another review found clearer benefits for people with PCOS, people who make many eggs, and cycles using PGT-A. For people with a typical response, frozen did no worse than fresh.
In people with a low chance of success: A 2025 trial in The BMJ studied 838 women at nine fertility centers in China. Each had 9 or fewer eggs collected, or signs of a low egg supply. Half were picked at random to freeze all embryos and half to have a fresh transfer. Live births were lower with freeze-all: 32% (132 of 419) compared with 40% (168 of 419). The authors said their results do not support routine freeze-all for women in this group.
The trial does not settle every choice. Each center chose its own number and stage of embryos to transfer, and the authors said this may partly explain the gap. It also did not study people with a typical or high response.
The Cochrane review also found freeze-all may raise the risk of high blood pressure in pregnancy and of a larger baby. Its authors said these findings are uncertain because they rest on few cases. Compare the two in fresh vs frozen transfer.
What happens after retrieval
1. Lab updates. You will be told how many eggs were collected before you go home. Over the next days, the lab updates you by phone or patient portal on how many fertilized and how many grew into blastocysts, which takes 5 to 6 days (rarely 7). Learn the terms in embryo development and lab reports.
2. Freezing. Embryos suitable for freezing are frozen with a fast method called vitrification. Your clinic will ask you to sign storage forms that say what should happen to your embryos in different situations. Embryo freezing and storage explains both.
3. A gap before transfer. There is no post-transfer pregnancy test to schedule, because no embryo was transferred. Ask what needs to happen before transfer and when your team expects to review the plan. If you feel anxious or low, tell your care team so they can offer support.
4. Frozen embryo transfer. In a later cycle, your lining is prepared and an embryo is thawed and placed in your uterus. Some clinics use your own natural cycle, and others use hormones. See frozen embryo transfer, natural FET and medicated FET.
How long until the frozen transfer, and what could delay it?
Your clinic sets the date. Studies that looked back at past cycles found a frozen transfer can be done as soon as the next cycle after retrieval, without lowering success rates. These things can push it later:
- PGT-A results. You wait for the report, and some embryos may come back with no result.
- Time for your ovaries to recover after stimulation.
- A lining that is slow to thicken. This may change the expected date, and you may need extra hormones and more monitoring.
- Thawing. Sometimes no embryo survives thawing, which leaves none to transfer that cycle.
- Your own timing. Frozen embryos can wait for years, so you can choose to start later.
Freeze-all milestone checklist
| Milestone | What to note |
|---|---|
| Retrieval day | Number of eggs collected |
| Day 1 | Number of eggs that fertilized |
| Days 5 to 6 (rarely 7) | Number of blastocysts and their grades |
| Freezing update | Number of embryos frozen, and any sent for PGT-A |
| PGT-A results (if used) | Number of embryos with normal results, and any with no result |
| Your next period | Whether your clinic wants a call that day |
| FET calendar | Start date for medicines and monitoring visits |
| Transfer day | Which embryo, and your pregnancy test date |
Questions to ask your clinic
- Why are we freezing all embryos this time, and would a fresh transfer be an option for me?
- If PGT-A is suggested, why for me, and how long do results take?
- Will my FET be natural or medicated?
- Who will call me with lab updates and results, and when?
- Should I call when my period starts?
- If an embryo doesn't survive thawing, what happens next?
Ask for an itemized cost estimate that lists each of these separately:
- Freezing the embryos
- Storage, and how often it is billed
- Embryo biopsy and PGT-A testing, if used
- Medicines for the transfer cycle
- Monitoring visits, including extra ones if your lining is slow
- Thawing, and any extra lab steps after thawing
- The frozen transfer itself
When to get help
OHSS can still happen after retrieval without a transfer.
Call your clinic right away, day or night, if you have:
- A fever of 100.4°F (38°C) or higher.
- Heavy bleeding: soaking a full-size pad with bright red blood in less than an hour, or bleeding heavier than a period.
- Belly or pelvic pain that is sudden or severe, gets worse, or isn't eased by the pain relief your clinic recommended.
- Pain and bloating in your belly, or bloating that is getting worse.
- Nausea and vomiting, nausea that won't go away, or you can't keep fluids down.
- Peeing less than usual, even if you are not thirsty.
- Fast weight gain. Your clinic will tell you its number, but do not wait to reach a weight threshold if you feel unwell.
- Dizziness, lightheadedness, or feeling faint.
- Pain, redness or warmth in an arm or leg.
- Blood in your urine, or pain when you pee or poop.
- Discharge from your vagina that smells bad.
Tell your clinic at your next contact about other milder symptoms that are new, don't go away or slowly get worse.
After your frozen transfer, the warning signs change. See after embryo transfer.
Key takeaway
Freeze-all lowers the risk of OHSS and makes time for testing, but it is not the better choice for everyone. Ask why it fits your plan, what could delay your transfer, and what each step will cost.