Surrogacy Success Rates: What the Numbers Actually Mean

You’ve seen the numbers. One agency claims 99%. Another says 75%. A fertility clinic reports 55%. And you’re sitting there, deep into a search at 2 a.m., trying to figure out which number actually applies to your situation.

Here’s the problem: surrogacy success rates can mean completely different things depending on who’s reporting them and how they define “success.” Some agencies count every family who eventually took a baby home — across multiple transfers, years, and surrogates. Others report the per-transfer live birth rate from a single embryo transfer.

Both numbers are real. Neither tells the whole story. And the metric that matters most for your baby’s safety — preterm delivery rate — almost never shows up on agency websites at all.

This guide breaks down every metric intended parents actually need, from per-transfer live birth rates to cumulative odds across multiple attempts. We’ll show you which factors move the needle most, what the peer-reviewed research says, and why the agency you choose shapes outcomes more than most people realize.

Why “Surrogacy Success Rates” Can Be Misleading

When you search for surrogacy success rates, the numbers you find depend on which metric the source is using. These are four very different measurements, and agencies don’t always make it clear which one they’re quoting.

• Implantation rate: The embryo attaches to the uterine lining. Detected by a blood test showing rising hCG levels. Ranges from 40–65% for tested embryos.
• Clinical pregnancy rate: Confirmed pregnancy via ultrasound showing a heartbeat, typically around 6–7 weeks. Higher than live birth rate because it doesn’t account for later losses.
• Live birth rate per transfer: A baby born alive after a single embryo transfer. The most honest per-attempt metric. Ranges from 50–80% depending on egg age and testing.
• Cumulative journey rate: Success across multiple transfer attempts, sometimes across multiple surrogates. This is the “95–99%” number most agencies advertise.

When an agency claims a 99% success rate, they almost always mean the cumulative journey rate. That’s real — most intended parents do eventually go home with a baby. But it can obscure the fact that some families need two or three transfers to get there.

Surrogacy Success Rates by Egg Provider Age

The age of the person who provided the eggs is the single most powerful predictor of transfer success. Not the surrogate’s age. Not the clinic’s reputation. The eggs.

Egg quality declines sharply after 35, affecting the percentage of embryos that are chromosomally normal (euploid). A woman under 35 produces euploid embryos roughly 61% of the time. By age 42, that drops to about 25%.

Here’s how live birth rates per transfer break down by egg source, based on data from the Society for Assisted Reproductive Technology (SART) and the CDC’s ART surveillance program:

If you’re using donor eggs from a woman in her 20s and testing embryos with PGT-A, you’re working with the highest per-transfer odds available in reproductive medicine. That’s a real number, not marketing.

The Cumulative Picture: Why Most Families Do Take a Baby Home

A 60% per-transfer rate might not sound overwhelming. But surrogacy contracts typically allow up to three transfer attempts, and the math gets encouraging fast.

After one transfer: roughly 60% of intended parents achieve pregnancy. After two transfers: 70–80%. After three: 80–95%+. The cumulative effect is why agencies can honestly claim that the vast majority of their clients become parents.

The catch is that each additional transfer costs more — in medication, compensation, clinic fees, and emotional energy. A failed first transfer doesn’t mean something went wrong. Implantation is probabilistic, even with a perfect embryo and a proven surrogate.

What matters is how your agency and clinic respond to that first failure. Do they adjust the protocol? Reassess the embryos? Or just try the same thing again?

When Surrogacy Goes Wrong: What the Headlines Teach Us

In September 2025, a WIRED investigation by Emi Nietfeld brought the story of venture capitalist Cindy Bi and Baby Leon into public view. Bi hired a surrogate to carry her male embryo in 2023. The surrogate experienced complications starting at 26 weeks, and the baby was stillborn at 29 weeks due to placental abruption.

What followed was a prolonged legal battle. Bi spent nearly a million dollars in legal fees pursuing the surrogate, publicly accusing her of causing the death. Medical evidence pointed to placental abruption — a condition driven by the pregnancy itself, not surrogate behavior.

The case exposed gaps that exist across the surrogacy industry. There was no physician oversight between the agency and the surrogate’s Obstetrician/Gynecologist (OB/GYN). Communication broke down as the pregnancy became high-risk. Insurance coverage fell through mid-pregnancy, creating financial conflict during a medical crisis.

Kim Kardashian’s surrogacy experience tells a different kind of story. After developing placenta accreta during two prior pregnancies — a condition where the placenta grows too deeply into the uterine wall — her medical team advised against carrying again. She used gestational surrogacy for her third and fourth children, Chicago and Psalm.

Kardashian’s openness about the medical reasons behind her choice helped normalize how surrogacy works for millions of families. It also illustrated a truth that applies to every intended parent: surrogacy works best when the decision is medically informed and the pregnancy is properly monitored.

The contrast between these stories isn’t about wealth or celebrity. It’s about the structural safeguards surrounding the pregnancy — screening, medical oversight, and the clinical infrastructure that sits between “embryo transfer” and “baby in your arms.”

Five Factors That Actually Drive Surrogacy Success Rates

Not all of these get equal attention, but research backs each one. Here are the five variables with the strongest evidence behind them.

1. Egg Quality and Donor Age

We covered this above, but it bears repeating: egg age is the dominant variable. A 2023 JAMA study analyzing over one million Assisted Reproductive Technology (ART) cycles found that gestational carrier cycles produced a higher adjusted rate of live births than standard In Vitro Fertilization (IVF) — an adjusted relative risk of 1.11. Surrogacy doesn’t just match IVF outcomes. It outperforms them.

2. PGT-A (Genetic Testing of Embryos)

Preimplantation Genetic Testing for Aneuploidy (PGT-A) screens each embryo for chromosomal abnormalities before transfer. It doesn’t change the total number of healthy embryos you have, but it prevents transferring embryos that were never going to succeed.

For intended parents over 38, the per-transfer impact is dramatic. Without PGT-A, implantation rates at age 38–40 run about 30%. With PGT-A, they jump to nearly 60%. Miscarriage drops from 27.7% to 13.6% in the same age bracket.

3. Single Embryo Transfer (SET)

The American Society for Reproductive Medicine (ASRM) strongly recommends transferring one embryo at a time in gestational carrier cycles. Double embryo transfer (DET) nudges the pregnancy rate up only marginally — from about 65% to 68% in one large study — but pushes the twin rate above 40%.

Twin pregnancies carry dramatically higher preterm birth risk. In one study, preterm rates hit 40% after double transfers compared to 13.4% after single transfers. That’s not a minor difference — it’s the gap between a baby spending weeks in the NICU and going home on schedule.

4. Surrogate Screening Quality

ASRM guidelines require surrogates to have at least one prior uncomplicated pregnancy, no more than five deliveries or three cesarean sections, and pass medical, psychological, and infectious disease screening.

But guidelines are a floor, not a ceiling. The rigor of the screening protocol — who designs it, who evaluates the results, and how edge cases get handled — varies enormously between agencies.

At Physician’s Surrogacy, the screening protocol is designed and evaluated by in-house board-certified OB/GYNs. That’s a structural difference. Most surrogacy agencies are managed by non-medical professionals who send screening results to external physicians for review. When an OB/GYN designs the protocol and evaluates every applicant directly, the medical judgment is built into the process from the start.

5. Pregnancy Monitoring and Medical Oversight

Once a surrogate is pregnant, success depends on what happens during the next nine months. This is where most agencies step back and hand off to the surrogate’s local OB. The agency’s role becomes coordination — scheduling updates, relaying information, managing logistics.

Physician’s Surrogacy operates differently. As the only surrogacy agency in the U.S. managed by practicing OB/GYNs, the medical team monitors clinical communications throughout the pregnancy. If complications arise, our physicians can consult directly with the surrogate’s managing OB — a peer-to-peer clinical conversation, not a phone call from a case manager.

We also offer optional OB-ordered antenatal testing that most agencies can’t provide: Non-Invasive Prenatal Testing (NIPT), NT sonograms, AFP Quad Screens, and fetal echocardiograms. These aren’t standard at other agencies because those agencies don’t have physicians on staff to order them.

The Metric Agencies Don’t Talk About: Preterm Delivery

When you evaluate surrogacy agencies, you’ll see journey completion rates, baby counts, and testimonials. What you won’t see — on any competitor’s website — is a clinical outcome metric like preterm delivery rate.

That’s a problem. Preterm birth is the leading cause of infant mortality and long-term health complications in the United States. The national preterm birth rate sits at 10.4%, according to the March of Dimes 2025 Report Card. The U.S. received a D+ grade for the fourth year running.

In surrogacy pregnancies specifically, preterm rates can run even higher — one study of 836 gestational carriers found an overall preterm birth rate of 15.1%, driven largely by multiple pregnancies from double embryo transfers.

Physician’s Surrogacy maintains a preterm delivery rate 50% below the national average. That translates to approximately 5% — well below the general population singleton rate of 8.8% and dramatically below the surrogacy-specific rates in peer-reviewed studies.

How? It comes back to the physician-led model. When OB/GYNs screen surrogates, monitor pregnancies, and intervene early when complications appear, preterm delivery goes down. It’s not a marketing claim. It’s a clinical outcome that flows from the way the agency is structured.

Miscarriage Rates in Gestational Surrogacy

Miscarriage in surrogacy pregnancies runs lower than or comparable to standard IVF. A 2026 scoping review in Reproductive Biology and Endocrinology found surrogacy miscarriage rates between 3.0% and 17.6% across studies. One study within that review reported a 3.0% miscarriage rate in gestational carrier IVF versus 10.9% in natural conception.

The reason? Gestational surrogates are, by definition, women with proven fertility — they’ve already delivered at least one healthy baby. Their uteruses are proven. Their bodies have done this before. That biological advantage isn’t available to most standard IVF patients.

PGT-A adds another layer of protection. For intended parents using their own eggs at age 41–42, miscarriage drops from 37.9% without testing to 13.9% with PGT-A. That’s cutting risk by more than half.

What Happens When a Transfer Doesn’t Work

A failed first transfer is not uncommon. Even with a tested embryo and a healthy surrogate, implantation is a biological event with inherent variability. Roughly 35–40% of first transfers don’t result in pregnancy. That’s the math, not a failure.

What matters is what happens next. A good fertility clinic will review the transfer protocol, assess embryo quality, check the surrogate’s uterine lining thickness and receptivity, and potentially adjust medication timing for the second attempt.

Most surrogacy contracts include provisions for multiple transfers. The emotional weight of a failed transfer is real — and any agency that treats it as purely procedural is missing the human side of the equation. At Physician’s Surrogacy, our intended parent team provides 24/7 multilingual support, and our physicians can discuss transfer outcomes and protocol adjustments directly with your fertility clinic.

How to Evaluate Surrogacy Success Rates Like a Clinician

Next time you see a surrogate success rate on an agency’s website, ask three questions before you take it at face value.

What’s the denominator? Is this per-transfer, per-journey, or per-family? A 99% rate across completed journeys looks different from a 60% rate per individual transfer. Both are valid, but they answer different questions.

Is it independently verified? Only one major U.S. surrogacy agency claims third-party auditing of their success data. Most self-report. There’s no industry standard for how agencies define or calculate these numbers.

Do they publish clinical outcomes? Journey completion tells you that a family eventually got a baby. Preterm delivery rate tells you how healthy that baby was at birth. The second metric matters just as much as the first, and almost no one reports it.

Gestational surrogacy is one of the most medically sophisticated ways a family can be built — and one of the most human. The numbers should give you confidence, not confusion. And the agency behind those numbers should be willing to show you the clinical data, not just the marketing version.

Why the Agency You Choose Changes Your Odds

The research is clear: surrogate screening quality, single embryo transfer compliance, and medical oversight during pregnancy directly affect gestational surrogacy success rates. Those aren’t things you can control from the intended parent side. They’re built into the agency you select.

At Physician’s Surrogacy, the physician-led model touches every stage. OB/GYNs design the surrogate screening protocol. The medical team reviews clinical updates throughout pregnancy. And if something goes wrong at 3 a.m., there’s a physician who can speak directly with your surrogate’s OB — not a coordinator reading from a chart.

Our Flat-Rate Surrogacy program starts at $140,000–$170,000+, with no agency fees until your match is confirmed. And with an average matching timeline of one week — compared to 6–12 months at most agencies — you’re not losing months in a waiting queue while your embryos sit in storage.

If you’re comparing agencies and the success rate conversation feels incomplete, ask the question most people don’t: who’s managing the medical side? Talk to our team and see what physician-led surrogacy actually looks like from the inside.

FAQ: Surrogacy Success Rates

Julianna Nikolic

Chief Strategy Officer Julianna Nikolic leads strategic initiatives, focusing on growth, innovation, and patient-centered solutions in the reproductive sciences sector. With 26+ years of management experience and a strong entrepreneurial background, she brings deep expertise to advancing reproductive healthcare.