The primary factor determining the success of an In Vitro Fertilization (IVF) program is the biological age of the wife at the time of egg retrieval. Unlike men, who continuously produce new sperm, women are born with a finite number of eggs. As age advances, ovarian reserve (the number of eggs remaining in the ovaries) and the genetic quality of the eggs gradually decline. Global statistical data from the CDC and SART provide guidance for setting realistic success expectations.
Why Does Egg Quality Decline With Age?
The decline in IVF success rates, which begins in the mid-30s and drops sharply after age 40, is caused by the failure of chromosomal division in oocytes (eggs) during meiosis—the specialized cell division process that produces a mature egg with the correct number of chromosomes. Aging eggs are prone to nondisjunction—an error in chromosome separation when the cell divides, resulting in eggs with either too many or too few chromosomes, which produces embryos with aneuploidy (an abnormal number of chromosomes).
Even the most advanced ovarian stimulation protocols (programs of hormone injections to stimulate the ovaries to produce more eggs in a single cycle) cannot repair the genetic damage in aging eggs. Consequently, there is an increase in the attrition rate—the failure rate of eggs developing into viable embryos, accompanied by a rise in miscarriage rates from 15% in younger women to over 40% in women over the age of 40.
Statistical Analysis of IVF Success Rates by Age Group
Based on national registry data from SART (Society for Assisted Reproductive Technology—an organization that collects and publishes IVF outcome data in the United States) and the CDC, IVF program success parameters are divided into several age groups:
Under 35 Years Age Group
This group has the highest chance of success because egg quality is still optimal. The LBR (Live Birth Rate—the percentage of cycles resulting in the live birth of a baby) per single embryo transfer reaches 45–55%, with SART data showing 53.2% per cycle. The cycle cancellation rate is very low (3.9%), with the cryopreservation rate (the percentage of embryos successfully frozen for use in subsequent cycles) reaching 90.0%. The eSET (elective Single Embryo Transfer—the intentional transfer of only one embryo to avoid multiple pregnancies) policy is applied in 94.5% of cases.
35 to 37 Years Age Group
A decline begins to show gradually. The LBR per transfer ranges from 32–40%, with a SART national average of 39.9%. The cycle cancellation rate rises to 6.3%, and the failure rate where no embryos are viable for transfer or freezing increases to 11.4%.
38 to 40 Years Age Group
This phase is a critical transition period. The LBR per transfer drops significantly to 20–26%. More than half of started cycles (53.7%) end without an embryo transfer, either due to cycle cancellation prior to retrieval (the process of retrieving eggs from the ovaries via a minor surgical procedure) (8.5%) or the absence of properly developing embryos (21.3%).
41 to 42 Years Age Group
The chances of success using one’s own eggs are in a low range, at 9–15% per transfer, with a national average LBR per initiated cycle of 13.2%. The failure rate to obtain a transferrable embryo surges to 32.3%, reflecting the high rate of embryo aneuploidy.
Over 42 Years Age Group
Cycles with one’s own eggs at this age have a very poor prognosis—predicted treatment outcomes based on the patient’s medical condition. The LBR per transfer is below 5% (SART national average: 3.7–4.1%). Nearly 80% of cycles end without an embryo transfer. The cycle cancellation rate reaches 15.9%, and 41.7% of the retrieved eggs fail to produce a viable embryo for transfer.
Donor Egg Strategy to Overcome Age Factors
For patients of advanced reproductive age, an alternative that offers a significantly increased chance of success is the use of donor eggs from young, healthy women (under 30 years old). Because the biological potential of an embryo is closely tied to the age of the egg at fertilization, a 45-year-old patient undergoing IVF using donor eggs from a 25-year-old woman can experience an increase in live birth odds from under 2% to over 50% per transfer. Success rates with donor eggs remain stable in the 51–54% range, unaffected by the uterine age of the recipient mother.
The Evolution of the Single Embryo Transfer (eSET) Policy
Historically, to compensate for poor embryo quality in older patients, clinicians tended to transfer multiple embryos at once. Past SART recommendations permitted the transfer of 1–2 embryos at age <35, 2–3 embryos at age 35–37, 3–4 embryos at age 38–40, and up to 5 embryos for patients over 40. However, this approach led to a high rate of twin and triplet pregnancies, which risk triggering premature birth and maternal complications.
Over the past decade, a major shift toward the application of eSET has occurred. National data shows the rate of single embryo transfers in the United States surged from 30.8% in 2013 to 85.9% in 2022. The implementation of PGT-A (Preimplantation Genetic Testing for Aneuploidy—genetic testing on embryos before uterine transfer specifically to detect chromosomal number abnormalities) in the over-35 age group helps facilitate eSET, as doctors can transfer a single embryo proven to be euploid (having a normal and complete number of chromosomes) with high confidence, thereby eliminating the risk of multiple pregnancies without compromising the chances of a live birth.
Summary of Statistical Data by Age Group
Age Group
LBR per Initiated Cycle
Cycle Cancellation Rate
Embryo Failure per Egg Retrieval
eSET Application
<35 Years
High (53.2%)
Very Low (3.9%)
Very Low (6.5%)
Highly Consistent (94.5%)
35–37 Years
Moderate (39.9%)
Low (6.3%)
Low (11.4%)
High (91.6%)
38–40 Years
Low (26.2%)
Moderate (8.5%)
High (21.3%)
Fairly High (82.4%)
41–42 Years
Very Low (13.2%)
High (11.3%)
Very High (32.3%)
Moderate (67.0%)
>42 Years
Critical (3.7%–4.1%)
Very High (15.9%)
Extreme (41.7%)
Low (37.8%)
Next Steps
Understanding the chances of success based on age groups helps you and your partner set realistic expectations and plan your IVF program steps more wisely.
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References
• National Summary Report – SART.
• Interpreting CDC fertility stats and Clinic Rankings – Liv Hospital.
• IVF Success Rate by Age: 2025 Statistics & Live Birth Odds – The Life Fertility Clinic.
• Understanding Fertility Success Rates – How to Read SART & CDC Tables – Texas Fertility Center.
• National ART Summary – CDC.
• Clinical management of mosaic results from preimplantation genetic testing for aneuploidy of blastocysts: a committee opinion – ASRM.
Disclaimer: This information is for educational purposes and does not replace a physician’s evaluation. Diagnostic and therapeutic decisions should be tailored to the examination results of you and your partner.
