Roughly 95% of the IVF cycles we perform are freeze-all cycles with embryo batching — embryos are frozen and transferred in a later cycle rather than immediately, and in many cases several retrievals are completed before any transfer takes place. SART, which publishes clinic success rates, links a retrieval to its outcome only when a transfer occurs within one year of that retrieval. Because our transfers routinely fall outside that twelve-month window, a large share of our retrievals are reported as retrievals with no transfer. That lowers our reported success rate without describing how those cycles actually ended.
SART says its own data should not be used to compare clinics
This is not our characterization. SART's national summary report states it directly:
The data presented in this report should not be used for comparing clinics. Clinics may have differences in patient selection and treatment approaches which may artificially inflate or lower pregnancy rates relative to another clinic.
Third-party websites nonetheless rank clinics against one another using these figures, and frequently set a clinic's rate beside a "national average" computed on a different basis entirely.
How a cycle is counted
A cycle is counted from the moment a patient starts medication for an ART procedure — not from transfer, and not from pregnancy. Every stimulation counts as its own cycle start, and a single cycle start can be credited with at most one live birth.
SART's own report gives the arithmetic: "if three successive ovarian stimulation cycles are performed... the delivery rate would be 1/3 (33%)." Three retrievals that together produce one healthy baby are reported as a 33% delivery rate.
For a program that banks embryos across several retrievals before transferring — which is what we do for most patients — that structure accumulates denominators while only one of them can ever carry a numerator.
Our own PGT-A outcomes for the past two years are published in full on our IVF success rates page — 87 retrievals, 59 with a euploid embryo available to transfer, and 45 deliveries — with the retrievals that produced no transferable embryo counted as failures rather than excluded.
What freeze-all does to the number
SART's reporting is designed not to disadvantage delayed transfers; its documentation states there is "no penalty for delayed transfer (freeze all)." The constraint is the twelve-month window. A transfer that happens thirteen months after a retrieval is a real transfer with a real outcome, but it is not linked back to that retrieval in the published report. The retrieval remains in the denominator with no outcome attached to it.
We freeze nearly all of our cycles and batch embryos deliberately, because for many patients it produces a better chance of a healthy pregnancy than transferring immediately. It is a clinical decision, not a reporting strategy — but it has a reporting consequence, and that consequence is visible in our published numbers.
Who a clinic treats changes its numbers
We do not accept or deny patients for treatment based on likelihood of success. Patients with prior failed cycles, diminished ovarian reserve or a poor prognosis are treated here rather than turned away or restricted to donor egg cycles only.
Our policy is also not to withhold data, including for poor-prognosis patients. Those cycles are reported like every other cycle.
Both choices lower a reported average. A program that declines difficult cases, or that reports selectively, will publish a higher number without having done anything better in the laboratory.
Program size and age
Chelsea Fertility NYC opened in 2014. Comparisons of absolute totals — cumulative births, cycles performed — between a program that opened in 2014 and one that opened in the 1980s measure how long a program has existed and how many cycles it runs each year. They do not measure the quality of care a patient will receive.
What to ask instead
When you are comparing programs, these questions tell you more than a single published percentage:
- Is the rate quoted per cycle started, per retrieval, or per embryo transfer? These produce very different numbers from the same cycles.
- Is it for one transfer, or cumulative across all transfers from one retrieval?
- Which age band does it describe, and does the comparison figure describe the same band?
- Does the program perform mostly fresh or mostly frozen transfers?
- Does the program restrict who it will treat, and on what criteria?
- What proportion of cycles are freeze-all, and how does that interact with the reporting window?
Common questions
Why do some websites show Chelsea Fertility NYC with a below-average success rate?
Roughly 95% of our cycles are freeze-all with embryo batching, and those transfers commonly occur outside SART's twelve-month reporting window. Those retrievals are published as retrievals without a transfer. We also treat patients with a poor prognosis rather than declining them, and we do not withhold those cycles from what we report. Both practices lower a reported average.
Does a freeze-all cycle work less well than a fresh transfer?
No. Freezing embryos and transferring them in a later cycle is a clinical decision made for the patient's benefit. It affects how a cycle appears in published reporting, not how well the cycle works.
Is SART data unreliable?
SART data is a valuable national registry. The limitation is in how it is used: SART itself states the report should not be used to compare clinics, because differences in patient selection and treatment approach can artificially raise or lower a clinic's rate relative to another.
What is the difference between a rate per cycle started and a rate per transfer?
A rate per cycle started counts every stimulation begun, including cycles that did not reach transfer. A rate per transfer counts only cycles that reached an embryo transfer. The same set of cycles will produce a substantially higher number when expressed per transfer. Comparing one clinic's per-cycle rate against another's per-transfer rate is not a valid comparison.
How long has Chelsea Fertility NYC been operating?
The program opened in 2014.
If you have had unsuccessful cycles elsewhere and want a reproductive endocrinologist to read your chart, see fertility second opinion, or contact Chelsea Fertility NYC.