A percentage without a denominator is not a result.

Pick the shape of the rate you were quoted. This explains what that denominator includes, what it quietly leaves out, and which questions are still open. You do not need to type the percentage anywhere — until the denominator is named, the number cannot be read.

A pregnancy rate counted over the transfers that actually happened. No egg source was named alongside the number.

Usually said as "our pregnancy rate is about…" — sometimes called clinical pregnancy or positive-beta rate.

This is a reading aid, not an assessment of any program. Your selections stay in this page — they are not saved or sent anywhere.

What is in the denominator, and what is missing

If nobody named the egg source, treat the number as unreadable for now. Own-egg and donor-egg outcomes are reported separately for good reason, and pooling them moves the figure.

Read any percentage along these dimensions

SART outcome tables are useful but must be interpreted by egg source, donor age, embryo type, denominator and reporting definitions.

• Egg source — whose eggs the cycle used.
• Donor age, wherever donor eggs are involved.
• Embryo type — fresh or frozen, blastocyst or earlier, biopsied or not.
• Denominator — per transfer, per retrieval, per cycle start, or per patient.
• Reporting definitions — what was counted as a pregnancy, a cancellation, and a completed cycle.

Never compare clinics using a single unadjusted percentage; small volumes create instability.

Why small-volume percentages wobble

• A percentage built on few cycles moves a long way on one or two different outcomes. With a handful of cycles in your age band, the same program can look quite different next year with nothing having changed.
• Ask for the count under the percentage. A rate without its sample size is a rate you cannot weigh.
• Case mix differs. A program that takes on harder cases reports lower unadjusted numbers for reasons that have nothing to do with the quality of the care.

About PGT-A

• PGT-A screens the sampled cells for specified chromosome findings. It does not guarantee implantation, live birth, or a child without disease.
• So a rate quoted "per euploid transfer" is a subgroup rate, not a per-patient rate — the embryos and cycles that never got a result are already outside it.
• Worth asking: which findings does the platform report, how are no-result and mosaic biopsies counted, and are untested embryos in the same table?

If a gestational carrier is involved

If a gestational carrier will carry the pregnancy, ask how the program reports those cycles and which patient the denominator refers to. Decisions about her own medical care rest with her, and no published percentage changes that.

Questions to bring to the consult

• Does "pregnancy" here mean a positive test, a confirmed heartbeat, or something else?
• Of everyone who started treatment, what share reached a transfer at all?
• What does the same group look like expressed per retrieval?
• Is this figure for own-egg cycles, donor-egg cycles, or both pooled together?
• Where is this figure published, and which reporting year is it from?
• How many cycles or transfers is the percentage based on?
• Which patients are in the denominator, and who was left out of it?
• Can I see the same outcome expressed per retrieval and per patient?

What this decoder will not do

• It takes no clinic names and holds no clinic data.
• It never compares or ranks providers, and will not turn a percentage into a verdict about a program.
• It copies no percentage into this page — read the current figures at the source, then interpret them along the dimensions above.
• It does not estimate your personal chance of a live birth. No tool here can do that.
• The output is a question list for a consultation, not a score.