Reference · Clinical · United States
The success rate on the clinic website is not the number that applies to you. Understanding which number is being reported and which is being omitted is the most important question you can ask before you pay.
IVF Daddies
Reference Platform
Decision Clarity System
Reference · Clinical · United States
What IVF Success Rates Actually Mean
This page explains one part of the system. It does not replace the full journey.
Short answer
Clinics report success rates per transfer, not per patient and not per live birth. These three numbers can differ by 40 percentage points at the same clinic. The number on the website is almost always the most favorable version of the data.
- Live birth rate per retrieval, not per transfer. Per transfer counts only cycles that reached a transfer, which excludes patients whose cycles were cancelled before transfer. Per retrieval is the honest denominator.
- Age-specific outcomes. A clinic's aggregate success rate includes patients in their 20s using donor eggs, which inflates the number significantly. What matters is the rate for patients in your age group using your type of cycle.
- Whether poor-prognosis patients are included in the reported cohort. Some clinics quietly decline patients they believe are unlikely to succeed, which improves their published numbers without improving their actual clinical capability.
- Comparing clinic A's clinical pregnancy rate to clinic B's live birth rate. These are not the same metric. Clinical pregnancy includes pregnancies that end in miscarriage. Live birth is the only number that measures the outcome you are actually trying to achieve.
- Treating a single successful cycle statistic as a prediction. A 60 percent live birth rate per transfer means that 40 percent of transfers do not result in a live birth. It does not mean your specific transfer has a 60 percent chance. Your individual factors, egg quality, uterine environment, embryo quality, and protocol all affect your personal probability.
- Assuming SART and CDC data are directly comparable across clinics. Clinics have some discretion in how they categorize and report cycles. Two clinics with identical outcomes could report different numbers depending on their internal classification practices.
- Choosing a clinic based on a headline number that does not represent patients with your clinical profile.
- Underestimating the number of cycles you will need to budget for. Most published statistics assume one transfer. Many patients require two or three.
- Missing the fact that some clinics have higher success rates partly because they use more aggressive protocols with higher multiple birth rates, which carries its own medical risk.
- When you meet with a clinic, ask this specific question: what is your live birth rate per retrieval for patients my age, using my own eggs, in the same clinical category as me?
- Ask whether that number includes patients who were cancelled before retrieval.
- Request the clinic's SART data directly and ask them to walk you through what it includes and excludes.
- If a clinic is reluctant to answer these questions specifically, treat that reluctance as information.
Your situation in the system
Stage: Orientation
Where you are
You are evaluating whether IVF is statistically viable for your situation.
What is likely blocking you
Most people stall here because published success rates do not distinguish between your age, diagnosis, and protocol. The numbers feel abstract.
This resolves
When you have your clinic's live birth rate per transfer for your specific age bracket, not their headline figure.
One thing to do now
Ask your clinic for age-specific live birth rate per transfer. Compare it to the CDC SART national data for the same bracket.
The three numbers clinics use and what each one means
Clinical pregnancy rate counts any pregnancy confirmed by blood test or ultrasound, including those that end in miscarriage. Ongoing pregnancy rate counts pregnancies past a defined gestational point. Live birth rate counts babies born alive. Only live birth rate measures the outcome you are pursuing. The gap between clinical pregnancy rate and live birth rate at a single clinic can be 15 to 25 percentage points.
Patient selection affects published outcomes more than most people realize
A clinic that accepts only good-prognosis patients will publish better numbers than a clinic of equal or superior clinical capability that accepts complex cases. When you see an unusually high success rate, one of the questions worth asking is: what percentage of patients who contact this clinic are declined for treatment?
What Emma Whitney said about this
Emma Whitney, Senior Embryologist and Lab Director at The Evewell, said in conversation with IVF Daddies that the success rate published on a clinic website does not represent at least 20 percent of the people who walk through the door. Understanding what a clinic excludes from its published data is as important as understanding what it includes.
Where this breaks down in real life
This is the moment where people misunderstand this decision. Most people look at clinic success rates the same way they look at hotel star ratings. This conversation explains why those two things are nothing alike.
Reference Media
This is one part of the system.
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