Age and IVF success
Where clinic-mean live-birth rates fall across CDC age bands, why egg quality drives the swing, and how to read those numbers without mixing case mix.
Disclaimer: This guide is for informational purposes only. It does not constitute medical advice. Age is one factor among many that affect IVF outcomes. Always consult a reproductive endocrinologist for guidance specific to your situation.
Age bands · CDC NASS clinic means
Clinic means in this NASS extract fall from 48% under 35 (399 clinics) to 8.8% at patients over 40 (303 clinics); about a 5.5× swing between those brackets; egg quality, not uterine age, drives most of that gap.
- 48%
- Under 35 mean (399 clinics)
- 22.5%
- Ages 38–40 mean (355 clinics)
- 8.8%
- Over-40 mean (303 clinics)
- 5.5×
- Under-35 ÷ over-40 ratio
Each band average covers only clinics that published that bracket; denominators differ. Means are not a personal probability.
Live clinic means by age band
Same NASS extract as the success-rates guide: horizontal age-band means plus the under-35 ÷ over-40 swing gauge. No hand-typed national ranges.
Clinic-mean live-birth rate by CDC age band
Averages across clinics that publish each band in this extract.
Under-35 ÷ over-40 mean ratio
Same extract: 48% ÷ 8.8% · about a 5.5× swing. Donor-egg cycles are reported separately by CDC.
Clinic counts per bar: Under 35 n=399 · 35–37 n=358 · 38–40 n=355 · Over 40 n=303.
Why age dominates the chart
The age effect in IVF is driven almost entirely by egg quality, not uterine receptivity. The uterus remains capable of carrying a pregnancy well into the 40s, as donor-egg success rates demonstrate. The eggs themselves are the limiting factor.
As eggs age, meiosis becomes more error-prone, producing eggs with too many or too few chromosomes (aneuploidy). Aneuploid embryos typically fail to implant or result in early miscarriage. IVF and PGT-A can help select chromosomally normal embryos when they exist; they cannot create normal embryos from abnormal eggs.
Ovarian reserve also declines with age, so older patients often retrieve fewer eggs per cycle. Fewer eggs plus higher aneuploidy rates means fewer transferable embryos, one reason older patients often need multiple cycles.
How to read the live bands above
- Under 35 - highest clinic-mean live-birth rates in this extract (about 48%).
- 35–37 - still relatively strong (about 35.3%).
- 38–40 - meaningful decline (about 22.5%).
- Over 40 - much lower with own eggs (about 8.8%).
Critical rule: only compare clinics within the same CDC age band. Mixing under-35 rates with overall or over-40 rates invents a false ranking.
What this means when you shortlist clinics
Use PlainFertility age-band rates as a discovery filter: shortlist clinics that publish competitive rates in your band, then talk with a reproductive endocrinologist about diagnosis, protocol, and cost. Time sensitivity rises after the mid-30s; after 40, many programs discuss donor eggs earlier because own-egg means fall sharply in the published bands.
Donor-egg cycles reset the egg-age clock: outcomes track the donor’s age far more than the recipient’s. CDC reports those cycles separately, do not blend them into the own-egg band chart above.
Frequently Asked Questions
At what age does IVF stop working?
IVF does not have a hard age cutoff, but clinic-mean live-birth rates with own eggs are much lower by patients over 40 (about 8.8% in this extract). Many clinics counsel patients in this range about donor eggs, which keep high success rates tied to the donor's age. Individual results still depend on ovarian reserve and embryo quality.
Why are IVF success rates so much higher for younger patients?
Egg quality is the primary factor. Younger patients produce eggs with lower rates of chromosomal abnormalities (aneuploidy). Chromosomally normal embryos are far more likely to implant, continue to a viable pregnancy, and result in a live birth. Compare clinics inside your own CDC age band, not across bands.
Does using donor eggs bypass the age factor?
Yes. When donor eggs are used, success rates are determined primarily by the donor's age, not the recipient's. The CDC reports donor-egg cycles separately from own-egg age bands for that reason.
Should I freeze my eggs at a younger age?
Egg freezing preserves fertility at the biological age of the eggs at the time of freezing. The decision is highly individual and should be discussed with a reproductive endocrinologist; clinic age-band rates are a discovery filter, not a personal forecast.
How does the CDC report success rates by age?
The CDC reports IVF success rates in age groups including under 35, 35–37, 38–40, and a single band for everyone over 40. In this PlainFertility extract the clinic means are about 48%, 35.3%, 22.5%, and 8.8% respectively. Always compare clinics within your own age group.