IVF success rate data is hard to read because the word “success” itself is defined differently from one report to the next: it can mean a positive pregnancy test in one report and a live birth in another, and each report can use a different denominator to calculate that percentage.
This guide helps you understand what these numbers actually mean, so you can bring real questions to your first consultation, not just the one big percentage a clinic puts on its website.
What Are IVF Success Rates Actually Measuring?
Most people assume “success rate” means “chance of having a baby,” but different clinics and databases actually measure different endpoints along the way, including a positive pregnancy test, a clinical pregnancy, or a live birth. Of these, live birth rate, sometimes called the take home baby rate, is the most meaningful metric because it’s the only one that reflects an actual baby coming home.
The Society for Assisted Reproductive Technology (SART) and the Centers for Disease Control and Prevention (CDC) both publish annual US fertility clinic outcome data, which is the foundation for comparing any clinic’s performance.
Because SART tracks outcomes for a full two years after each cycle starts, the most recently published report is always about two years behind the current year, with each year’s data listed as “preliminary” first and “final” the following year.
Fertility Specialists of Texas (FST) reported 2,615 total in vitro fertilization (IVF) cycles in 2023, with a 96.3% retrieval start report rate, one of the highest in the field, according to SART’s patient guide.
Live Birth Rate vs. Pregnancy Rate: Why It Matters
A positive pregnancy test is not a baby, and a clinical pregnancy is not a guarantee of delivery, which is why the distinction between these measures matters so much. FST’s 2023 data, the most recent final report available due to that same two-year reporting lag, reports live births per intended egg retrieval, the most honest measure available because it counts every cycle that started, rather than only the ones that made it further along.
For people under 35 at FST, the live birth rate was approximately 55.7% per intended retrieval, according to FST’s SART Clinic Summary Report. That number means something different from “positive pregnancy tests per retrieval,” and the difference is exactly why the take home baby rate matters more than any other figure on the page.
Why You Can’t Compare Clinics Side by Side
Both SART and the CDC state directly that comparing clinics to one another is not scientifically valid, largely because clinics serve different patient populations. FST is a clear example of why that matters.
FST’s own SART notes disclose that they perform a significant number of preimplantation genetic testing (PGT) cycles and encourage some individuals to complete multiple retrievals before transfer, practices that are associated with better long term outcomes but can make per-cycle live birth rates look lower next to a clinic that does fewer of them.
That context is exactly what changes how the numbers should be read.
A comparison of clinic success rates may not be personally applicable because patient medical characteristics, treatment approaches, and entry criteria for ART may vary from clinic to clinic.
What Clinic Selection Practices Can Inflate Numbers
Some clinics discourage people with a lower likelihood of success from pursuing treatment, or move most cases to donor eggs, in ways that can make their published numbers look stronger than they would otherwise. But FST takes the opposite approach.
Rather than selecting only the cases most likely to succeed, FST accepts people with a lower chance of success and builds individualized protocols around their specific situation, which is part of why direct comparisons between clinics can be so misleading.
Ask your care team directly about patient selection practices when you’re reviewing any clinic’s data, since that context matters as much as the numbers themselves.
How Age Affects the Data, and Why It’s the Most Important Variable
Age at egg retrieval is the single strongest predictor of IVF outcome, and FST’s 2023 data shows this clearly across age brackets, using a person’s own eggs across all transfers:
- Under 35 was approximately 55.7% (454 cycle starts)
- 35 to 37 was approximately 42.2% (275 cycles)
- 38 to 40 was approximately 28.9% (194 cycles)
- 41 to 42 was approximately 15.8% (95 cycles)
- Over 42 was approximately 11.4% (70 cycles)
These brackets reflect age at retrieval, not age at transfer, which matters if you banked embryos in an earlier cycle and are transferring them later, according to the CDC’s guide to interpreting ART success rates.
Own Eggs vs. Donor Eggs: Separate Data Sets
Success rates for cycles using a person’s own eggs are reported separately from cycles using donor eggs, because the variable driving the outcome is different in each case. Donor egg cycles typically show higher rates since the donor’s age, not the recipient’s, is what matters most.
This is a different pathway with a different data set, not a “better” one.
Understanding How Cycles Are Counted
Success rate is a fraction: live births divided by something, and that something can be intended retrievals, actual retrievals, or embryo transfers. The same clinic’s numbers can look very different depending on which denominator is used, which is why the denominator matters as much as the number on top.
Per intended retrieval is the most honest and inclusive measure, since it counts every cycle that started, including cycles that never reached transfer. FST’s data is a useful illustration of this, since they count cycles where a person undergoes multiple retrievals before transfer as separate cycles, which is clinically appropriate and reflects their PGT-heavy protocol, but also means their per-cycle rate looks different from a clinic where most people transfer after a single retrieval.
Neither approach is wrong, they’re simply counting different things.
Fresh vs. Frozen Embryo Transfer Success Rates
Frozen embryo transfer (FET) rates are now comparable to, or higher than, fresh transfer rates at many clinics. FST performs a significant proportion of elective single embryo transfers, a practice their own SART notes flag directly, and one that reduces the risk of multiple pregnancy while maintaining strong outcomes.
That context is useful for reading FST’s numbers, not a caveat against them.
How to Find and Read FST’s SART Profile
To find FST’s SART profile, go to sartcorsonline.com, search for Fertility Specialists of Texas, and open the Plano location report. The columns break down cleanly once you know what they mean: age bracket, live births per intended retrieval, number of cycles, and confidence range.
A number on a page doesn’t predict any one person’s outcome, so bring FST’s data to your first consultation, where a specialist can walk through what it actually means for your specific situation on FST’s success rates page.
What the Numbers Can’t Tell You
Success rates measure outcomes, not what it feels like to be in treatment. Whether you’re treated with respect, whether you feel heard, and whether a practice takes the time to answer your questions aren’t things a SART report can quantify, but they matter just as much when you’re navigating a process that can take months or longer.
A clinic’s data is one part of the picture, and how it feels to sit in the waiting room is another.
Your Questions About the Numbers Deserve Real Answers
You now have a framework for reading success rate data the way it’s meant to be read, and the clearest next step is a conversation with a specialist who can put these numbers in context for your specific situation.
Request an appointment at FST and bring your questions with you.
