Fresh vs Frozen Embryo Transfer: Pros, Cons & Success Rates

One of the decisions in your IVF journey is whether to do a fresh embryo transfer (immediately after egg retrieval) or freeze embryos and transfer later. Both approaches have advantages, and the best choice depends on your specific situation.

Key Takeaways

• FET slightly better: Frozen embryo transfers show 45-50% pregnancy rates vs 40-45% for fresh transfers
• Why FET works: Allows uterus to recover from stimulation, enables genetic testing (PGT-A)
• Modern freezing is safe: Vitrification achieves 95-98% embryo survival rates
• Cost difference: FET adds EUR 1,500-2,500 to total treatment cost
• Your choice matters: Medical factors (OHSS risk, lining quality) and personal preferences both play a role

Understanding the Difference

Fresh Embryo Transfer

Embryo is transferred 3-5 days after egg retrieval, during the same cycle.

Timeline:

• Day 0: Egg retrieval
• Days 1-5: Embryo development
• Day 3 or 5: Transfer
• Day 15-19: Pregnancy test

Frozen Embryo Transfer (FET)

Embryos are frozen after retrieval and transferred in a later cycle.

Timeline:

• Cycle 1: Egg retrieval, embryo freezing
• Gap: 1-3 months (or longer)
• Cycle 2: Uterine preparation, embryo thaw, transfer
• 2 weeks later: Pregnancy test

Success Rates Comparison

Transfer Type	Clinical Pregnancy Rate	Live Birth Rate
Fresh transfer	40-45%	35-40%
Frozen transfer	45-50%	40-45%

Key finding: Recent studies show FET may have slightly higher success rates for many patients.

Why FET Sometimes Performs Better

1. Uterus recovery: After stimulation, the uterine lining may not be optimal. FET allows it to recover.

2. Hormone normalization: Stimulation medications affect hormone levels. Natural or medicated FET cycles have more physiological conditions.

3. Better embryo selection: Watching which embryos survive freezing can help select the strongest.

4. Reduced OHSS risk: Patients at risk of ovarian hyperstimulation can freeze all embryos and avoid complications.

When Fresh Transfer Is Recommended

Your clinic may recommend fresh transfer if:

• Good response to stimulation without risk of OHSS
• Uterine lining looks optimal on ultrasound
• You prefer single treatment cycle to minimize trips/time
• Financial constraints (FET adds cost)
• Fewer embryos (less to choose from later)

When FET Is Recommended

Your clinic may recommend FET if:

• OHSS risk: High estrogen or many follicles
• Thin uterine lining: Needs time to improve
• PGT-A testing: Requires time for genetic results
• Elevated progesterone: Affects implantation window
• All embryos frozen: Due to medical reasons
• Preference for natural cycle: Transfer in unstimulated cycle

Pros and Cons

Fresh Transfer

Pros:

• One treatment cycle
• Less time overall
• Lower total cost
• Fewer trips if traveling

Cons:

• Uterus may not be optimal
• No genetic testing possible (not enough time)
• Higher OHSS risk maintained
• Less flexibility in timing

Frozen Embryo Transfer

Pros:

• Uterus fully recovered
• Time for PGT-A if desired
• Better embryo selection
• Eliminates OHSS risk
• Flexible timing
• Slightly higher success rates

Cons:

• Requires second cycle
• Additional cost (€1,500-2,500)
• More medications
• Additional trip if abroad
• Small risk of embryos not surviving thaw (rare with vitrification)

FET Cycle: What to Expect

Natural FET

Transfer timed to your natural ovulation:

• Monitor natural cycle with ultrasounds
• Transfer 5 days after ovulation
• Minimal medications
• Works if you have regular cycles

Medicated FET

Hormones prepare your uterus:

• Estrogen tablets/patches to build lining
• Progesterone to prepare for implantation
• Transfer after adequate lining confirmed
• More control over timing

Timeline

Day	What Happens
Days 1-14	Estrogen to build lining
Day 12-14	Ultrasound to check lining
Day 14+	Start progesterone
Day 19-21	Embryo thaw and transfer
Day 33-35	Pregnancy test

Cost Comparison

Component	Fresh Cycle Only	Fresh + FET Later
IVF + fresh transfer	€4,000-5,500	€3,500-4,500
Embryo freezing	—	€300-500
FET cycle	—	€1,500-2,500
Total	€4,000-5,500	€5,300-7,500

FET adds €1,500-2,500 to your total cost.

Embryo Survival Rates

Modern vitrification (flash-freezing) has excellent survival rates:

Metric	Rate
Embryo survival after thaw	95-98%
Embryo quality maintained	95%+

Freezing is very safe for embryos with current technology.

Frequently Asked Questions

Does freezing damage embryos?

No. Vitrification preserves embryos excellently. Survival rates are 95-98%. Frozen embryos perform as well as fresh in most studies.

How long can embryos stay frozen?

Indefinitely. Healthy babies have been born from embryos frozen 20+ years. There's no known time limit.

Can I choose fresh or frozen?

Usually, yes—but your clinic may strongly recommend one based on your response to treatment. Trust their expertise.

If I'm traveling for treatment, which is easier?

Fresh transfer requires one longer trip (10-14 days). FET requires two shorter trips (initial cycle + transfer week). Total time abroad is similar.

What if my fresh transfer fails—can I still do FET?

Yes, if you have frozen embryos. This is one advantage of freezing extras.

Making Your Decision

Discuss with your clinic based on:

• Your response to stimulation
• Uterine lining quality
• OHSS risk
• Whether you want PGT-A testing
• Travel and timing constraints
• Financial considerations

Both approaches can lead to successful pregnancies. The "right" choice is the one that fits your medical situation and circumstances.

Book a free consultation to discuss which approach might be best for you.

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Nestiva helps you understand your IVF options in Portugal, including fresh and frozen transfer decisions.