Written by Shweta Rathod, MD — Doctor of Medicine, clinical experience in Obstetrics & Gynecology, labour room management, and IVF. Dr. Rathod writes Surrogacy4All’s pregnancy and obstetric content.
Medically reviewed by Rashmi Gulati, MD —
- Board Certified, Internal Medicine
- Medical Advisor, Surrogacy4All
- Privileges at Mount Sinai Hospital.
Last updated [14/09/2026]
Summary
Transferring a single euploid embryo to a gestational carrier gives a live birth rate per transfer close to that of a double transfer while cutting the twin rate from roughly a third of pregnancies to under 2%.
Twin pregnancies carry several times the risk of preterm birth, NICU admission and maternal complications, risks borne by a surrogate who is carrying for someone else.
Single euploid embryo transfer is therefore Surrogacy4All’s standard, and it is why our reported success rates — 65% first transfer, 90% cumulative per SART — are achieved without multiples.
Surrogacy4All is NYS-licensed (GSP220903), physician-led, operating since 2006.
| Fact | Value |
|---|---|
| Surrogacy4All protocol | One euploid (PGT-A-tested) blastocyst per transfer |
| Twin rate, single euploid transfer | Under 2% (monozygotic splitting) |
| Twin rate, double transfer | Roughly 30–40% of pregnancies |
| Preterm birth (<37 weeks), twins vs singletons | About 60% vs about 10% (national birth data) |
| National carrier-cycle data | {live birth per transfer, singleton share — SART National Summary, year} |
| Surrogacy4All success rates | 65% first transfer, 90% cumulative — per SART |
| Success rates (source) | SART |
Why Does the Number of Embryos Matter More in Surrogacy Than in Own-Uterus IVF?
Because the person carrying the risk is not the person making the choice.
In own-uterus IVF a patient may accept a higher twin risk for a higher chance of pregnancy. In surrogacy the carrier bears the medical risk, the intended parents bear the cost and NICU exposure, and the contract has to allocate decisions about reduction and preterm delivery in advance.
ASRM’s guidance recommends single embryo transfer for gestational carriers, and New York’s licensing framework expects agencies to protect the carrier’s health.
What Do the Outcomes Data Show?
Insert SART National Summary figures for gestational carrier cycles: live birth per transfer for single vs double transfers, and the singleton share, with year.
The pattern across published series is consistent : with a euploid embryo, the live birth rate from one transfer is in the same range as from two, because the second embryo adds mostly twin pregnancies rather than additional singleton births.
The twin pregnancies then carry roughly six times the preterm birth rate, higher rates of preeclampsia and cesarean delivery for the carrier, and NICU stays for the babies that can run into weeks.
Does PGT-A Change the Calculation?
Yes, it is what makes single transfer efficient.
Transferring an untested embryo means some transfers fail for chromosomal reasons, which historically pushed clinics toward two embryos.
A euploid blastocyst implants at a substantially higher rate, so one is enough to reach the same probability of a baby.
That is why our embryo plan for every intended parent includes PGT-A where the clinic can perform it.
What If Intended Parents Want Twins?
We explain the numbers above and, in nearly every case, recommend against a double transfer.
Where a clinic and a carrier agree to it under a specific contract clause, the compensation for multiples (+$5,000) and the medical plan for a twin pregnancy are set out in advance.
A second child is planned as a second single transfer, often with the same carrier.
How Does This Affect the Timeline and Cost?
A failed single transfer costs about three to four months and the transfer fee, a second euploid transfer is funded from escrow, which is why we budget for it.
Across the journey, single transfers reach 90% cumulative live birth with fewer complications and lower total medical cost than a double-transfer strategy that produces twins a third of the time.
Frequently Asked Questions
Q. How Many Embryos Are Transferred to a Surrogate?
A. One, at Surrogacy4All.
Q. What Is the Success Rate of a Single Embryo Transfer?
A. With a euploid embryo, in the same range as a double transfer; 65% first transfer and 90% cumulative in our program per SART.
Q. Can Twins Still Happen?
A. Rarely, if a single embryo splits (under 2%).
Q. Why Are Twins Riskier in Surrogacy?
A. Preterm birth, preeclampsia and cesarean rates are several times higher, and the carrier bears the risk.
Q. Is PGT-A Required?
A. Strongly recommended, it is what makes one embryo enough.
Q. Can We Transfer Two If We Accept the Risk?
A. Only by specific agreement with the clinic and the carrier; we recommend against it.
Talk to a Physician-Led Team
Free consultation, in person on Fifth Avenue or by video:
Dr. Pooja Patel
Dr. Pooja Patel is a Chief Surrogacy Coordinator at Surrogacy4all. She has 10 years of experience in Anesthesiology and critical care medicine.
She received her medical degree from Seth GS Medical College and K.E.M Hospital in India. She then completed an internship. She finished her Anesthesia residency at Grant Govt Medical College and JJ Group of Hospitals in India.
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Rashmi Gulati
Rashmi Gulati, MD, provides innovative, individualized health care that nurtures mind, body, and spirit. Since 2004 she has been the medical director at Patients Medical, where she delivers comprehensive personalized health care, treating each patient as a respected, unique individual. Through their integrative health care center in the heart of Manhattan, Dr. Gulati and her colleagues have become premier care providers serving patients locally and throughout the world.
- Rashmi Gulati
- Rashmi Gulati
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