IVF After 40: Looking at the Cumulative Numbers As They Are
You will often hear that even if one IVF cycle does not work, cumulative success rates rise with repeated attempts. That is true. But how much they rise differs enormously by age. Left vague, "don't give up yet" is encouragement rather than information.
This article sets out the actual numbers.
What cumulative live birth rate means
It is the proportion of people who eventually have a baby across multiple treatment cycles, rather than after a single retrieval and transfer. Even when the per-cycle chance is low, repetition raises the overall figure.
There are two ways to calculate it.
- Conservative estimate — anyone who stops treatment is counted as not having had a live birth
- Optimistic estimate — those who stopped are assumed to have succeeded at the same rate had they continued
The conservative estimate is closer to reality; the optimistic one is better read as an upper bound. The two can differ by more than double, so it matters which one you are being shown.
The numbers by age
A 2025 retrospective study followed 343 women with diminished ovarian reserve (DOR) through 996 retrieval cycles over three years. Cumulative live birth rates after six retrieval cycles were reported by age group as follows (conservative / optimistic estimate, PMID: 40652184):
- Under 35: 57.4% / 82.7%
- 35-39: 41.1% / 64.8%
- 40 and over: 14.7% / 26.0%
Across the whole group, the figures were 41.1% conservative and 81.0% optimistic.
Look at that last row again. After six retrievals, the conservative estimate for women aged 40 and over is 14.7%. The authors concluded that beyond four cycles the additional benefit for women aged 40 and over is limited, recommending continued treatment for younger patients and individualised counselling, including alternative options, for older ones.
This was a single-centre retrospective study in women with diminished ovarian reserve. Your own test results change the picture, so treat these as reference points.
How to read these numbers
"Repetition raises your chances" is true. "After 40 the rise is shallow and plateaus early" is equally true.
Presenting only one of these is kinder in appearance and less honest in substance, because only someone who knows the odds can decide when to stop.
Some things worth settling in advance:
- Decide how many cycles before you start. Making the decision afresh after each result is exhausting and makes clear thinking harder
- Build in review points. Finishing three cycles is a natural moment to discuss continuing, pausing, or considering other paths
- Pausing is not retreat. Staying physically and financially able to continue is itself what keeps options open
The emotional load
Repeated retrievals mean injections and anaesthesia, and a repeating cycle of hope and disappointment. Time pressure, other people's expectations and the cost all add to it. Finding this hard is not a failure of attitude.
You do not have to stay relentlessly positive. Talk to your partner or someone you trust, or use counselling — whatever you can sustain.
Deciding with your doctor
Treatment plans differ from person to person. Discuss concretely with your doctor how many cycles to aim for and where to reassess, based on your age, ovarian reserve and history.
The figures above are a starting point for that conversation. A reasonable question is simply: "Where do I sit relative to these numbers?"
Frequently Asked Questions
Q1: When should I start IVF if I am over 40?
A1: Because ovarian function declines with time, seeing a specialist and getting tested sooner rather than later is generally advised. Time itself is a major factor.
Q2: How many retrievals should I do?
A2: There is no single answer. In the study above, additional benefit beyond four cycles was limited for women aged 40 and over. Setting a provisional limit before starting, and reviewing at intervals, is a practical approach.
Q3: What if repeated cycles do not work?
A3: Further testing for implantation failure, different treatment approaches, donor eggs and adoption are all possibilities. Whichever you consider, make the decision knowing the odds, in discussion with your doctor or a counsellor.
Summary
It is true that cumulative success rates rise with repeated IVF after 40. It is equally true that six cycles still leave a conservative estimate of 14.7%.
Holding on to hope and knowing the numbers are not in conflict. Knowing them is what lets you set your own limits.
References
- Retrospective cohort study on cumulative live birth rate of in vitro fertilization/intracytoplasmic sperm injection after multiple complete cycles in patients with diminished ovarian reserve. BMC Pregnancy Childbirth. 2025. PMID: 40652184 (a single-centre retrospective study of 343 women with diminished ovarian reserve)