Clinical pregnancy per transfer, ongoing pregnancy, live birth per transfer and cumulative live birth per retrieval are not interchangeable. Without the denominator, outcome, age stratum, sample size and reporting period, a published rate cannot be compared fairly.
The more fundamental problem is: any statistics come from a specific population. Your age, embryo quality, choice of whether to do PGT-A, surrogate conditions-these determine where you fall in the range, not the average.
| variable | Influence dimension | Specific instructions |
|---|---|---|
| embryo quality | lowest level determinants | The number of eggs retrieved, fertilization rate, and blastocyst formation rate directly determine how many embryos are available for embryo transfer. Without high-quality embryos, all subsequent steps are impossible. |
| PGT-A | Embryo-selection information | PGT-A tests chromosome copy number in cells biopsied from a blastocyst. It is not an embryo-quality certificate and does not guarantee a higher cumulative live-birth rate per retrieval. |
| laboratory level | Technical execution quality | Fertilization method (ICSI vs conventional in vitro fertilization), blastocyst culture conditions, and cryopreservation technology will all affect embryo viability and final transfer results. |
| Surrogate conditions | stability during pregnancy | The uterine environment, previous pregnancy history, age, and physical condition of surrogates directly affect the embryo implantation rate and duration of pregnancy. |
| Usable embryos and transfers | Cumulative outcome | The number of usable embryos determines how many transfers are possible. Cumulative outcomes should include all embryos from the same retrieval, not only patients who reached transfer. |
PGT-A provides information about chromosome copy number in trophectoderm biopsy cells and may change embryo-selection or transfer order. A better result among embryos that reach transfer is not the same as more live births from each retrieval. Biopsy, freezing, mosaic or false-positive results, inconclusive tests and the possibility of fewer embryos remaining for transfer must also be discussed.
In the IVF-surrogacy process, the physical condition of the surrogate is one of the key variables that affects implantation and maintenance of pregnancy. A strictly screened surrogate usually has the following characteristics:
For the commissioning family, the cumulative success rate is often more meaningful than the success rate of a single embryo transfer, because it is closer to the core question of "can I finally take my baby home?"
| concept | definition | Reference significance |
|---|---|---|
| Single embryo transfer clinical pregnancy rate | Proportion of detectable heartbeat after single embryo transfer | Evaluates the efficiency of a single transfer, but does not represent the final result |
| Ongoing pregnancy rate | Proportion of pregnancy continuing beyond 12 weeks | Excludes early miscarriage and is closer to actual live birth expectations |
| live birth rate | Proportion of final live births | The most realistic outcome indicator, but the data collection cycle is long |
| Cumulative live birth per retrieval | Live births arising from all embryos obtained in one retrieval | Better reflects the overall outcome of a complete retrieval |
Compare cumulative live birth per retrieval, the planned number of transfers and the next step after a failed transfer—not only the outcome of the first selected embryo.
PGT-A may reduce the number of embryos remaining for transfer while adding selection information. Ask the clinician to compare no testing, testing and further embryo-banking strategies across time, cost and cumulative live-birth potential.
Eggs from younger donors generally have lower rates of embryonic aneuploidy, which is the main medical rationale for this pathway. Actual outcomes still depend on the donor's response, the number of blastocysts obtained and laboratory standards, so ask for that centre's stratified data for donor-egg cycles rather than relying on a generic range.
Family structure does not itself predict medical success. Outcomes still depend on gametes, embryos, laboratory performance, gestational-carrier health and transfer strategy; legal eligibility and birth documentation require a separate review.
A more realistic approach is to split the project into three levels of expectations to manage:
Understood in this way, the success rate is no longer a floating number, but a process that can be managed in stages. For most families, this is of more practical value than asking, "Will it be successful?"
Our source review did not identify a nationally published, consistently defined and audited Kyrgyz surrogacy live-birth rate. This page therefore does not relabel U.S. surveillance data, one clinic's marketing rate or a per-transfer result as “the Kyrgyzstan success rate.”
| Measure | Denominator | Question answered |
|---|---|---|
| Clinical pregnancy per transfer | Embryo transfers performed | Whether a transfer produced a clinical pregnancy |
| Live birth per transfer | Embryo transfers performed | Live-birth outcome after transfer |
| Cumulative live birth per retrieval | One retrieval and all transfers in a defined follow-up period | Total reproductive potential of a retrieval |
| Live birth per patient or programme | Patients or programmes entering treatment | Includes those who never reach retrieval, embryo or transfer |
CDC distinguishes per-retrieval, per-transfer and cumulative outcomes and cautions that clinic populations differ. ASRM's 2024 opinion says the value of routine PGT-A screening for all IVF patients has not been demonstrated.
A truly reliable expression of success rate often makes people more rational, because it talks about opportunities and limitations at the same time. Being able to clearly explain "why there is an opportunity" and "what are the uncertainties" at the same time shows that the organization has a clear enough understanding of its own plan.
If you feel more and more excited to ask questions during the consultation, but you still can't get a specific breakdown of the numbers, it's worth stopping and asking a few more specific questions.
Want to understand the evidence, limits and decision points for PGT-A?