How many IVF cycles do most people need?

Cumulative live birth rates keep climbing across three cycles, which is why NICE guidance is built around three. Many successful outcomes come on the second or third attempt.

Does a failed first cycle mean IVF won't work for me?

No. It gives your clinic real information about how you respond, which is often used to change the protocol for the next attempt.

Success rates and odds

What are IVF success rates by age?

7 min read · updated September 2026

Short answer:Using a woman's own eggs, the chance of a live birth per embryo transfer in the UK is roughly 30–35% under 35, around 25% at 35–37, around 18% at 38–39, around 10% at 40–42, and under 5% over 42. Donor egg cycles sit around 30–35% regardless of the recipient's age, because the odds follow the age of the eggs rather than the person carrying them.

Success rates are the most quoted and least understood numbers in fertility treatment. They are not wrong — they are just answering a narrower question than the one you are asking.

The broad picture

Live birth rate per embryo transferred, using the patient's own eggs, falls steadily with age. Approximate UK figures look like this:

Under 35: around 30–35%
35–37: around 25%
38–39: around 18%
40–42: around 10%
43–44: around 5%
45 and over: under 3% with own eggs

The driver is egg chromosomal normality, which declines with age. It is also why donor egg cycles hold steady at roughly 30–35% no matter the recipient's age.

Per cycle, per transfer, per patient

Three different denominators produce three very different numbers from the same clinic:

Per cycle started — includes cycles cancelled before collection. The lowest and most honest figure.
Per embryo transfer — excludes anyone who never reached transfer. Higher, and the most commonly advertised.
Per patient, or cumulative — the chance of a birth across all transfers from one egg collection. The most useful figure for planning, and the least often published.

If a clinic quotes a success rate, ask which denominator it uses, which age band it covers, and whether it counts donor egg cycles. A headline figure that mixes those things is marketing, not data.

Why cumulative rates matter more

One egg collection often produces several embryos, and each transfer is a fresh chance. A 32-year-old with three good blastocysts has a considerably better than 35% chance of a baby from that single collection, even though each individual transfer sits around that mark. This is the arithmetic that makes freezing so valuable, and it is why a first negative does not carry the meaning people fear.

What else moves your own odds

Ovarian reserve — AMH and antral follicle count predict how many eggs you get, not their quality
Sperm quality, particularly where ICSI and DNA fragmentation are involved
The cause of infertility: tubal factor tends to respond well, severe endometriosis less so
Uterine factors such as fibroids, polyps and adhesions
BMI and smoking, both of which have a measurable effect
Whether the embryo transferred was tested and euploid

How to compare clinics without being misled

Use the HFEA's published data rather than clinic websites — it standardises the numbers and separates them by age band. Then judge whether a clinic's figures are above or below the national average for your age. And treat a clinic that markets a headline rate well above the national average with more curiosity than excitement: it usually reflects the patients they choose to accept.