The source: the HFEA's national data
In the UK every licensed fertility clinic reports its treatments to the Human Fertilisation and Embryology Authority (HFEA). Its report Fertility treatment 2023: trends and figures, published on 26 June 2025, is the most complete national picture available (HFEA, Fertility treatment 2023). The HFEA labels its 2023 figures as preliminary: they had not yet been fully validated when the report came out.
In 2023 there were more than 77,500 IVF cycles, undertaken by about 52,400 patients, plus about 5,500 donor insemination cycles. IVF led to about 20,700 births, up from about 8,700 in 2000. That is 3.1% of all UK births, or roughly one baby in 32.
"Per embryo transferred": the unit that matters
The HFEA reports success as a rate per embryo transferred. That choice matters. A rate per embryo transferred is not the same as a rate per cycle started (some cycles are stopped before any transfer) or a rate per patient over several cycles (which is higher, because people often have more than one attempt). Before comparing any two figures, check that they use the same denominator.
The HFEA also distinguishes pregnancy rates from birth rates. Not every pregnancy ends in a birth, so birth rates are always lower, and they are the figure that answers the question most patients ask.
Age is the biggest single factor
For IVF using fresh embryos created with the patient's own eggs, the 2023 national average birth rate was 25% per embryo transferred. By age:
| Age group (own eggs, fresh transfer) | Pregnancy rate per embryo transferred | Birth rate per embryo transferred |
|---|---|---|
| 18–34 | 41% | 35% |
| 35–37 | 34% | not given in the report text |
| 38–39 | 25% | not given in the report text |
| 43–44 | 9% | 5% |
| All ages | 31% | 25% |
Source: HFEA, Fertility treatment 2023: trends and figures (preliminary data, published June 2025). Intermediate age bands are shown only in the report's charts.
The drop with age reflects egg quality and quantity, which decline over the late thirties and forties. It is the main reason the same clinic can quote very different results to two patients.
Fresh or frozen?
Frozen embryo transfers now do at least as well as fresh ones on average: in 2023 the national figures were a 39% pregnancy rate and a 33% birth rate per embryo transferred for frozen transfers. Freezing also allows clinics to transfer one embryo at a time and keep the others, which helps explain a major change of the past fifteen years.
Fewer twins
Multiple pregnancies carry higher risks for mothers and babies. The HFEA set clinics a target of keeping multiple births below 10%. In 2023 the IVF multiple birth rate was 3.4%, well under that target, largely because single-embryo transfer has become standard.
Who pays
The share of IVF cycles funded by the NHS has fallen: 27% of UK cycles in 2023, against 35% in 2019. It varies widely by nation: 24% in England, 33% in Wales, 49% in Northern Ireland and 54% in Scotland. The NHS website explains the national eligibility criteria: under 40, up to three full cycles may be offered after two years of trying or twelve cycles of artificial insemination; at 40 to 42, one full cycle, if certain conditions are met. Local integrated care boards decide who is funded and may add criteria (NHS, IVF, reviewed April 2025).
Differences between groups
The report also shows that outcomes are not equal across patients: Asian and Black patients had lower birth rates (27% and 25%) than White patients and patients from a mixed ethnic background (33% and 30%). The HFEA treats these gaps as an area that needs further research.
How to use these figures
- Compare like with like: same age group, same type of transfer, same denominator.
- Look at birth rates, not only pregnancy rates.
- Remember that national averages are not personal predictions. A clinic can give an estimate based on your own tests and history.
Clinics also sell optional extras on top of IVF. The HFEA rates the evidence behind each one; see IVF add-ons: what the evidence shows. For a longer view, read how IVF went from one birth in 1978 to a routine treatment.
These are national statistics, not medical advice. A fertility clinic can explain what they mean for your own situation.
What happens in an IVF cycle
A standard IVF cycle has several steps, and each one is a point at which a cycle can end without a transfer. First, hormone medicines stimulate the ovaries to produce several eggs instead of the usual one. The response is monitored with ultrasound scans and sometimes blood tests. When the follicles are ready, a final injection prepares the eggs, and they are collected under sedation with a fine needle guided by ultrasound.
In the laboratory the eggs are mixed with sperm, or a single sperm is injected into each egg (ICSI), and the resulting embryos are grown for a few days. One embryo is then transferred into the womb, and any other suitable embryos can be frozen for later use. A pregnancy test follows about two weeks after the transfer.
This sequence explains why the denominator matters so much. A rate per cycle started includes cycles in which few eggs were collected or no embryo developed; a rate per embryo transferred only begins at the last step.
Comparing clinics
The HFEA publishes clinic-level information on its website so that patients can compare clinics on a consistent basis, including birth rates and multiple birth rates. Clinic results should be read with care: a clinic that treats many older patients or more complex cases may have lower average results while providing excellent care. The national averages in this article are a better guide to what is typical than any single clinic's headline figure.
Before starting
Most people reach IVF after a period of trying and a first set of tests, described in how common is infertility? It helps to ask early how many cycles are funded, what happens to frozen embryos, and which extras the clinic will suggest, so that decisions are not made under time pressure.