Can You Transfer Two Embryos to a Surrogate?

Short answer: Two embryos can sometimes technically be transferred in a gestational-surrogacy cycle, but transferring two is generally not the preferred approach. The American Society for Reproductive Medicine (ASRM) strongly recommends single-embryo transfer in gestational-carrier cycles because a multiple pregnancy increases health risks for the surrogate and the babies.

Why is one embryo usually preferred?

The goal of embryo transfer is not simply to maximize the chance of pregnancy in a single attempt. It is to maximize the chance of a healthy pregnancy and birth while minimizing avoidable risk.

Transferring two embryos can result in twins if both implant. Multiple pregnancies carry higher risks than singleton pregnancies, including preterm birth and pregnancy complications. This is especially important in surrogacy because the gestational carrier is taking on pregnancy-related risk to help intended parents build their family.

Does transferring two embryos double the chance of success?

No. Transferring two embryos does not mean the chance of a successful live birth simply doubles. Embryo quality, the age of the person who provided the eggs, embryo-development stage, whether embryos were genetically tested, the surrogate's medical circumstances and the fertility clinic's protocol can all affect the outcome.

For this reason, the number of embryos to transfer should be a clinical decision made with the fertility clinic rather than a shortcut intended to reduce the number of transfer attempts.

What do current guidelines say?

ASRM guidance strongly recommends single-embryo transfer in all gestational-carrier cycles because of the health risks associated with multiple gestation. ASRM's ethics guidance also describes single-embryo transfer as the preferred approach for gestational-carrier cycles.

There can be individual clinical circumstances in which a physician discusses a different approach, but the decision should follow current embryo-transfer guidance and an individualized medical assessment. The gestational carrier must also give informed consent to the medical care performed on her body.

What if intended parents want twins?

Wanting to complete a family in one pregnancy is understandable, but intentionally increasing the likelihood of twins also increases medical risk. The possibility of twins, multifetal pregnancy reduction and other pregnancy-related decisions should be discussed before embryo transfer as part of medical counseling, psychological preparation and the legal process.

The surrogate's health and autonomy remain central. Intended parents can discuss their preferences, but the surrogate is the source of consent for procedures performed on her body.

What should intended parents ask their fertility clinic?

• Why are you recommending one embryo or more than one in our specific case?
• What is the estimated chance of implantation with this embryo?
• How does embryo quality or PGT-A status affect your recommendation?
• What are the risks if both embryos implant?
• Would transferring embryos one at a time provide a safer overall strategy?

The bottom line

Although two embryos may sometimes be considered, single-embryo transfer is generally the preferred and strongly recommended approach in gestational-surrogacy cycles. The final plan should be based on the fertility clinic's medical assessment, current professional guidance and the surrogate's informed consent.

If you are still preparing for transfer, you may also want to read How Many Embryos Do You Need for Surrogacy?, Is PGT-A Required for Surrogacy?, and what happens after matching and before embryo transfer.

This article is general educational information and is not medical or legal advice. Your fertility clinic and independent legal counsel should advise you based on your circumstances and jurisdiction.