Reference · IVF Daddies · v2026.3
IVF Success Rates by Age
Bottom line
IVF success declines with maternal age because chromosomal abnormalities increase in eggs. Patients under 35 achieve approximately 50% live birth per transfer. Rates fall to ~40% at 35-37, ~25% at 38-40, ~15% at 41-42, and below 5% after age 42 when using their own eggs. Donor egg cycles bypass age-related decline entirely.
By Julio Gaggia · Co-founder, IVF Daddies
Definition
Age-stratified IVF success rates describe the probability of a live birth per embryo transfer, grouped by the age of the person providing the oocytes at the time of retrieval.
Function
Used to contextualize expected outcomes and inform treatment planning based on population-level data.
Constraint
Published rates represent averages across heterogeneous patient populations. Individual outcomes depend on embryo quality, uterine factors, and protocol selection.
Live Birth Rates by Maternal Age Group
The table below summarizes population-level live birth rates per embryo transfer using own eggs, stratified by the age of the egg provider at the time of retrieval.
| Age group | Live birth rate per transfer (own eggs) | Key biological factor |
|---|---|---|
| Under 35 | ~46% | Highest oocyte quality and ovarian reserve |
| 35–37 | ~38% | Early decline in oocyte competence |
| 38–40 | ~26% | Accelerating aneuploidy rates |
| 41–42 | ~13% | Substantially reduced blastocyst yield |
| Over 42 | ~5% | Majority of oocytes chromosomally abnormal |
Approximate values derived from SART national summary reports. Rates vary by clinic, protocol, and embryo selection method.
Why Age Is the Primary Variable
Age affects IVF outcomes through several interconnected biological mechanisms:
- Chromosomal abnormality rates. The proportion of aneuploid oocytes increases sharply after age 35, reaching approximately 80 percent by age 42.
- Ovarian reserve. AMH levels and antral follicle counts decline with age.
- Blastocyst formation. Fewer oocytes reach the blastocyst stage as maternal age increases.
- Implantation rates. Even when embryos are transferred, implantation probability declines with age due to both embryo and uterine factors.
Donor Eggs and Age
When donor eggs are used, the age of the intended parent carrying the pregnancy has a limited effect on success rates. The relevant age variable shifts to the egg donor's age at retrieval.
Population data shows that donor egg cycles maintain live birth rates of approximately 50 percent per transfer regardless of the recipient's age.
Cumulative Probability and Age
Per-transfer success rates determine how many cycles are required to reach a given cumulative probability:
CLBR = 1 − (1 − p)n
p. Per-transfer live birth probability (age-dependent).
n. Number of transfer attempts.
At p = 0.46 (under 35), three transfers yield approximately 84 percent cumulative probability. At p = 0.13 (age 41–42), three transfers yield approximately 34 percent.
Scope Limits
- This page provides population-level statistical context.
- It does not provide medical advice or treatment recommendations.
- It does not estimate individual probability of success.
- It does not compare specific clinics or treatment protocols.
Common Misunderstandings
- A single IVF cycle does not guarantee pregnancy.
- Attrition occurs at every biological stage.
- Published success rates may use different measurement units.
- Population statistics do not equal individual outcomes.
Data Reference
Primary population references include SART national outcome reports and peer reviewed fertility datasets. These values represent population level outcomes and should not be interpreted as predictions for individual patients.
Knowledge Graph
Related reference pages and tools in this system.
Core References
Clinical Models
Legal and Governance
Sources
- Society for Assisted Reproductive Technology (SART) national reports, https://www.sart.org
- Human Fertilisation and Embryology Authority (HFEA) statistics, https://www.hfea.gov.uk
- European Society of Human Reproduction and Embryology (ESHRE), https://www.eshre.eu
This content describes statistical patterns in IVF outcomes. It does not constitute medical advice.