Single vs Double Embryo Transfer: What’s Safer for Surrogacy?

What Is Single vs Double Embryo Transfer?

Single Embryo Transfer (SET)

Only one high-quality embryo is placed into the surrogate’s uterus.

Double Embryo Transfer (DET)

Two embryos are transferred at the same time to increase the chance of pregnancy—but also increase the chance of twins.

Which Option Is Safer? — Single Embryo Transfer Wins

For surrogacy, SET is considered the safest and medically preferred option.

Why?

Because carrying twins dramatically increases risks for both the surrogate and the babies.

Key Differences at a Glance

Factor	Single Embryo Transfer (SET)	Double Embryo Transfer (DET)
Pregnancy success	High with good-quality embryos	Slightly higher chance of pregnancy
Risk of twins	Very low	High (up to 40–50%)
Risk to surrogate	Lowest	Significantly higher
NICU/preterm birth	Low	High
Cost	Lower overall	Can increase due to complications
Recommended by doctors	✔ Yes	❌ Usually No

Why Single Embryo Transfer Is Recommended in Surrogacy

1. Lower Risk for the Surrogate

A twin pregnancy increases the chance of:

• Gestational diabetes
  
• Hypertension / preeclampsia
  
• Bed rest
  
• Preterm labor
  
• Delivery complications
  

Surrogacy programs prioritize surrogate health. Therefore, most agencies—including Surrogacy4All—recommend or require SET.

2. Healthier Outcomes for the Babies

Twins are:

• More likely to be born prematurely
  
• More likely to require NICU stay
  
• More vulnerable to low birth weight
  
• At higher risk of long-term health complications
  

Single embryo pregnancies consistently show better neonatal outcomes.

3. Higher Overall Success with Modern Embryology

Today’s PGT-tested (genetically screened) or high-grade blastocyst embryos provide strong pregnancy rates—even with one embryo.

Most IVF centers report:

• 50–70% success per SET with PGT-tested embryos
  
• No benefit from transferring two embryos of the same quality
  

4. Cost Efficiency

While DET may seem cost-saving at first (one transfer instead of two), complications from a twin pregnancy often increase:

• Medical bills
  
• Travel
  
• Required surrogate support
  
• NICU costs
  
• Delivery expenses
  

SET avoids these risk-based expenses.

5. Legally and Ethically Preferred

Surrogacy follows strict medical and ethical standards:

• Many reproductive societies (ASRM, ESHRE) advise SET for surrogacy.
  
• Some countries’ surrogacy laws prohibit DET unless medically justified.
  
• Agencies and clinics must protect surrogates from avoidable risks.
  

When Is Double Embryo Transfer Considered?

Doctors may consider DET only in rare cases:

• The embryos are not PGT-tested
  
• The intended mother is above age 40
  
• Previous repeated failed embryo transfers
  
• Embryos of lower quality
  

Even then, the clinic evaluates the surrogate’s health before approving.

Should Intended Parents Choose SET or DET? — Expert Recommendation

Single Embryo Transfer is the safest, most ethical, and medically recommended option for surrogacy.

DET may slightly increase the chance of pregnancy—but it greatly increases risks to both the surrogate and the babies.

Intended parents who want to maximize success should focus on:

• High-quality embryos
  
• PGT testing
  
• Clinic success rates
  
• A well-prepared surrogate uterus

…rather than transferring more embryos.

FAQs 

Q. What is the difference between Single and Double Embryo Transfer?

Ans : Single Embryo Transfer places one embryo into the surrogate’s uterus, while Double Embryo Transfer places two. DET increases the chance of twins but also increases risks.

Q. Which option is safer for surrogacy?

Ans : Single Embryo Transfer (SET) is medically safer. It lowers the risk of complications for the surrogate and results in healthier outcomes for the babies.

Q. Does Double Embryo Transfer improve success rates?

Ans : DET slightly increases pregnancy rates but dramatically increases the chances of twins. With modern PGT-tested embryos, SET offers strong success rates without added risk.

Q. Why do clinics prefer Single Embryo Transfer for surrogacy?

Ans : Because surrogates must be protected from high-risk pregnancies. SET reduces the chances of preterm birth, C-section, hypertension, and NICU stays.

Q. Can intended parents request Double Embryo Transfer?

Ans : Yes, but approval depends on medical evaluation. Many clinics and agencies deny DET unless there is a strong clinical reason due to safety concerns.

Q. Is Single Embryo Transfer more cost-effective?

Ans : Yes. DET may seem cost-saving, but twin pregnancies often lead to higher medical costs, travel expenses, and additional support needs.

Q. Do genetically tested embryos increase SET success?

Ans : Yes. PGT-tested embryos have higher implantation and pregnancy rates, making SET highly effective.

Q. Are twin pregnancies riskier for the surrogate?

Ans : Yes. Twins increase risks of preeclampsia, gestational diabetes, preterm labor, and delivery complications. That’s why SET is recommended.

Q. Do surrogacy laws affect embryo transfer decisions?

Ans : Many countries restrict DET in surrogacy to protect surrogate health. Clinics follow ethical and legal guidelines that prioritize safety.

Q. What do experts recommend—SET or DET?

Ans : Medical experts overwhelmingly recommend Single Embryo Transfer in surrogacy for the safest pregnancy and best health outcomes.

Final Decision: Safety First

Surrogacy is a shared journey. Surrogates give an extraordinary gift, and part of ethical surrogacy is ensuring their safety and comfort. SET supports:

• A healthier pregnancy
  
• A safer delivery
  
• Better birth outcomes
  
• Lower risk for everyone involved
  

For these reasons, Surrogacy4All and Dr. Pooja Patel strongly recommend Single Embryo Transfer for surrogacy cycles.