Understanding IVF success rates
Most patients considering IVF want to know the odds that the process will end with a healthy baby. One of the first places many people look for IVF success information is the Society for Assisted Reproductive Technology (SART), which tracks fertility centers’ success rates with various IVF procedures.
Data reported to SART reflect each clinic’s track record of success, but are not a prediction of your personal outcomes from IVF. As our research director likes to say, “Patients aren’t cycles.” Your fertility specialist will be able to tell you your approximate chances of success based on your age, diagnosis, specific procedure and any other relevant factors. If your doctor determines that your chances of success with traditional IVF may be low, many other options are available to increase the odds that you will bring home the baby you’ve been dreaming of.
IVF success rates: What to look for
When comparing SART data for our Las Vegas fertility clinic against other centers’ stats, be sure that you are comparing “apples to apples.” For example, success rates with traditional IVF in women younger than 35 will be higher than success rates for women older than 40, as age is a critical factor in IVF success. However, live birth rates for women using donor eggs do not depend on the age of the hopeful parents.
There are several other important factors to keep in mind when studying and comparing fertility centers’ IVF success rates.
- Single vs. multiple embryo transfer: The best fertility centers have high pregnancy and birth rates with single embryo transfers. Some clinics transfer multiple embryos to artificially boost their success rates, which may mask poor clinical practices and laboratory techniques. It also places women at a higher risk of twin, triplet or even higher-order pregnancies. Pregnancy with multiples involves added risks to the woman carrying the baby and the child. Our Las Vegas IVF clinic can achieve high IVF success rates, usually exceeding national averages, while routinely transferring just one embryo because we are very confident in our clinical skills and laboratory practices. We still offer transfer of a second embryo in selected cases, in which patients are deliberately seeking twins and have accepted the added risks. We will not transfer more than two embryos under any circumstances.
- Availability of embryos to transfer: Egg quality and quantity decline as women age, so when women are closer to menopause or are diagnosed with low ovarian reserve, it’s not always possible to retrieve and successfully fertilize enough eggs. However, if one or more embryos can be created in an IVF cycle, the odds of a successful embryo transfer are essentially the same for women of any age.
- Invisible factors behind the numbers: A failed cycle, as reflected by SART data, could have many causes unrelated to the quality of the fertility center. For example, a failure might be documented if a woman doesn’t respond well to medications and her IVF cycle is cancelled or no eggs fertilize, or if embryos are created but are not transferred because genetic testing determines they are chromosomally abnormal.
- Timing of reporting: SART data are reported annually. To be counted as a success, a cycle of IVF must have its first embryo transfer within 12 months of egg retrieval. Otherwise, SART counts the cycle as a failure, even if the first transfer results in a live birth. The latest data from SART are called “preliminary” because successful frozen embryo transfers in the following calendar year are not yet included. This complicated system counts failures immediately, but defers many successes for one year, creating a downward bias in preliminary success rates. The final versions of SART’s reports take one year longer to produce, but are more reliable because they include all first transfers, including those resulting in pregnancy. This is why we recommend avoiding the preliminary reports and relying on only the final reports for non-donor cycles.
- Own eggs vs. donor eggs: Some fertility centers have strict criteria for allowing women to proceed with IVF using their own eggs. For example, some refuse to attempt IVF in women with diminished ovarian reserve, pushing them toward donor eggs. These clinics’ IVF success rates may be artificially inflated, as women with a lower chance of success using their own eggs are eliminated from the pool of IVF cases reflected in those clinics’ SART data.
With all of this in mind, we believe that the most valuable measures of a fertility center’s IVF success rate are its live birth per patient and live birth per embryo transfer data. For both of these measures, our Las Vegas fertility clinic’s IVF success rates are consistently higher than the national average, across all age groups.
The above rates count all of the following as failures:
- Any patient or couple who produced no oocytes or embryos.
- Any patient who had embryos, but never returned for an embryo transfer. For example, a patient might not have had any embryos of the gender she wanted, so she never returned.
- Patients who had one or more embryo transfers, but did not have a live birth.
The live birth rate per transfer is the percentage of patients who have viable embryos to transfer and have a child following an embryo transfer. The LBR per transfer is very similar among all age groups of women. However, some will not have viable embryos to transfer, particularly women older than 38 who are using their own eggs.
When viewing per-transfer IVF success rates, please keep in mind that many centers exclude patients who started the IVF process, but never received an embryo transfer, so these figures will be higher than birth rates per cycle start.
We are here to help
While publicly available IVF success rate data can be a good measure of a clinic’s overall quality, only a reproductive endocrinologist can fully evaluate all factors that may have an impact on your personal results from any type of fertility treatment.
To learn more about our Las Vegas IVF clinic’s IVF success rates or to schedule a personal consultation with a fertility specialist, contact us today.