What is a realistic IVF success rate at 40?

For women aged 38 to 40, US national data (SART 2024) shows a live birth rate of about 18.5% per intended egg retrieval, falling to roughly 8.8% at 41 to 42 and 2.8% over 42. A clinic may quote a higher number because it measures per embryo transfer, which excludes cycles that never reached transfer. With donor eggs from a young donor, success is much higher and depends on the donor’s age, not yours.

Why do clinics show such high success rates?

Most clinics quote their best-looking metric, usually live birth per embryo transfer, which leaves out cycles cancelled before transfer and counts only the most favourable patients. Registry figures measured per cycle or per egg retrieval are lower because the denominator is wider. Neither is "wrong", but they are not the same number, so always ask which one a clinic is showing you.

Are IVF success rates abroad different?

The biology is the same everywhere: age is the dominant factor. What differs is how clinics report results and whether the data is independently audited. Treat a foreign clinic’s headline rate with the same scrutiny as a domestic one, and ask for the per-cycle figure for your specific age group.

Does PGT-A improve my odds?

PGT-A (screening embryos for chromosome number) can reduce the chance of transferring an embryo that will not implant, but high-quality evidence has not shown it raises the cumulative live birth rate for most patients, and it adds significant cost. It is an add-on to discuss critically with a specialist, not a guaranteed improvement.

IVF Success Rates by Age: What Clinics Don't Tell You

The short answer IVF success falls steeply with age. US national data (SART 2024) shows live births per egg retrieval of about 42% under 35, 30% at 35–37, 18% at 38–40, 9% at 41–42 and 3% over 42. Clinics often advertise higher numbers because they measure per embryo transfer, a narrower denominator. Ask which number you are being shown.

If you are weighing IVF, at home or abroad, the most important number is also the most often misrepresented. This page gives you the honest version: where the real figures come from, how to read them, and how to tell a fair success rate from a flattering one.

Honest success by age band

The chart below shows live-birth rate per intended egg retrieval from the US Society for Assisted Reproductive Technology (SART) 2024 reporting, using your own eggs. "Per intended egg retrieval" is one of the more honest denominators because it counts every cycle that set out to produce a baby, not only the ones that reached an embryo transfer.

Under 35 41.7%

35–37 29.6%

38–40 18.5%

41–42 8.8%

Over 42 2.8%

Source: SART CORS 2024, live birth per intended egg retrieval, own eggs. 2024 data labelled preliminary.

Per transfer vs per cycle vs per retrieval: the trick is the denominator

The single biggest way success rates mislead is the denominator. The same clinic, same patients, can honestly publish very different percentages depending on what they divide by:

How it is measured	What it counts	Effect
Per embryo transfer	Only cycles that reached a transfer	Highest number. Excludes cancelled cycles and poor responders.
Per intended egg retrieval	Every cycle that started a retrieval	Lower, more honest. Includes cycles with no usable embryo.
Per cycle started	Every cycle begun	Lower still. The European ESHRE registry’s delivery rate per aspiration was about 16% (IVF) in 2019.
Cumulative (per egg collection, all transfers)	Fresh plus all frozen transfers from one retrieval	Can be higher, and is the fairest view of one retrieval over time.

None of these is dishonest on its own. The dishonesty is quoting the highest one without saying so. When a clinic advertises "60% success," your only useful follow-up is: per what, and for which age group?

What a clinic’s "60% success" really means

A 60% headline is almost always per transfer, for the most favourable age band, sometimes with donor eggs included. For a 39-year-old using her own eggs, the honest per-retrieval figure is closer to 18%. That is not a reason to give up; it is a reason to plan for more than one cycle and to budget accordingly. Clinics that show you per-cycle figures for your age, without prompting, are the ones to trust.

The donor-egg exception

Egg donation changes the maths because success tracks the donor’s age, not the patient’s. European ESHRE registries show fresh donor-egg pregnancy rates per transfer around 50–51%, versus roughly 33–35% for own-egg IVF. That gap reflects the youth of donor eggs, not a property of donation itself. It is why donor cycles are often recommended at older maternal ages, and why their success figures should never be blended with own-egg numbers in a single advertised rate.

Cumulative vs single-cycle

One retrieval can yield several embryos, and transferring them across multiple attempts raises the chance of an eventual birth. So a single-cycle figure can understate your real chance over a full course of treatment, while a per-transfer figure overstates the chance of any one attempt. Ask your clinic for the cumulative live-birth rate per egg retrieval for your age. It is the number that best answers "what is my realistic chance of a baby from this?"

Red flags in clinic marketing

A headline success rate with no denominator and no age group attached.
Donor-egg results blended into a general "our success rate."
Rates that do not fall with age (real own-egg rates always do).
"Guarantee" or "money-back" programmes presented as evidence of high success rather than as financial products.
Selecting only the best-prognosis patients, then quoting the group’s results to everyone.

Read this alongside our cost-by-country guide and the Eligibility + Cost Finder: honest odds plus honest cost is the only fair basis for a decision this important.

IVF success rates by age: the honest numbers