Reading clinic success rates carefully

When you are choosing a clinic, a success number can feel like the one solid thing to hold onto. Numbers are useful. They are also easy to misread, especially when two clinics describe theirs in different ways.

This guide will not tell you what a good number is. It will help you ask what a number actually means, so that you can talk it through with your doctor.

What exactly is being counted

Every rate is a fraction: this many of that many. Before you compare anything, find out both parts.

• Per what? Per cycle started, per egg retrieval, per embryo transfer, or per person? These can be very different things, so they should not be lined up against each other.
• Which outcome? A positive pregnancy test, a pregnancy that continued, or a live birth? Each one describes a different point on the path.
• Which treatment? Is the number about a particular kind of treatment or about all of them together?

If a page or a brochure does not say, that is a fair thing to ask the clinic about.

Which patients the number describes

A rate describes a group of people. Ask which group. Is it everyone who was treated, or a smaller group defined by age or by a certain diagnosis? Would someone in your situation fit into that group?

A number that describes a very different group than yours may not tell you much about your own path. That is not a flaw in the number. It just means you need to ask what it is describing.

How recent the numbers are

Timing matters. CDC's national ART summary is based on cycles performed in the selected year, and pregnancy outcomes may fall in that year or the next. So even official data describes what happened in the past.

The same idea applies to a clinic's own figures. Ask which year or years the numbers cover, and whether anything has changed at the clinic since then, such as its staff or its methods.

If you want to understand the terms and what ART means, CDC's overview of assisted reproductive technology is a plain place to start, and ReproductiveFacts.org has patient fact sheets from ASRM.

A group's history is not a promise

A clinic's number describes what happened to past patients as a group. It is not a promise about what will happen to you, and it is not a prediction about any one person. The same is true of a national number.

It is tempting to treat the highest number as the best clinic. Try instead to treat every number as one piece of information, alongside things that matter to you: how you are treated, how clearly they explain, what they will cost and how close they are.

Questions to ask a clinic about its numbers

Bring these to a consultation or a phone call. You can build your own list with our Questions to ask tool, which includes a First consultation list.

• Where do the numbers you quote come from, and which years do they cover?
• What exactly are you counting, and per what?
• Which patients does this include? Does it match someone in my situation?
• How many patients or cycles are behind this number?
• Are there patients or cases that are left out, and why?
• How do your numbers compare with what you would expect for me, and what is that based on?
• Can you show me where I can check this myself?

These are fair questions to ask at any clinic. You can also look up member clinics with SART's clinic finder and ask each one the same questions, so the answers are easier to compare.

Using the SART predictor as a conversation starter

SART's IVF success predictor is a tool you can try. Treat what it gives you as something to talk about, not as an answer.

• Write down what you entered, what it showed and the date.
• Bring the printout or your notes to your doctor.
• Ask what your doctor thinks the tool leaves out, and what they know about your situation that a general tool cannot.
• Ask what they would want to learn before making a plan.

If a number worries or discourages you, say so at your appointment. Your care team can help you look at it in context, and you do not have to take it on alone.