Understanding IVF success rates

Most patients considering in vitro fertilization (IVF) want to know the likelihood that the process will end with a healthy baby. One of the first places many people look for IVF success rates is the Society for Assisted Reproductive Technology (SART), which tracks fertility centers’ success rates with different IVF procedures. Click here to view our Clinic Summary Report on SART.  Click here to view the success rates at our Las Vegas fertility center on the Centers for Disease Control clinic data summary report.

While these reports reflect each clinic’s track record of success, they cannot predict your personal outcomes from IVF. After all, each patient is unique. As such, our Las Vegas fertility doctors can tell you your approximate chances of success based on your age, diagnosis, chosen procedure(s), and any other relevant factors.

Unfortunately, the national reports count all the following as failures:

• Patients who did not return for an embryo transfer within one year, even if they had a live birth in a transfer more than one year later.
• Patients using IVF for sex selection, but who had no embryos of their preferred sex, so they did not return for embryo transfer.
• Patients who had embryos frozen at one center but shipped them to another center for transfer are counted as failures at the first center, even if live birth(s) resulted after embryo transfer at the other center.
• Patients who had all their embryos frozen and had their first embryo transfer in the subsequent calendar year.  SART instructs that any failed cycles in the subsequent year are counted immediately as failures, but the successful cycles (pregnancies) are deferred until the report is finalized the following year so that birth outcomes can be known.  This causes a negative bias in the success rates because the preliminary reports preferentially include failures but exclude successes until the final version of the report is issued one year later.  This bias is greatest for centers that freeze all embryos, such as the Fertility Center of Las Vegas. Therefore, the true success rates per patient or per cycle are often higher than shown in the reports.

What else should you consider when reviewing IVF success rates?

Clinical methods, laboratory equipment, and the patient population can all affect success rates. As a result, when comparing SART data for clinics, be sure that you are comparing “apples to apples.” For example, age is an important factor. As such, success rates for IVF (without donor eggs) in women under 35 are usually higher than those for women over 40.  In addition, the physician’s experience and training can make a difference in success and safety.  All three physicians at our Las Vegas fertility center are sub-specialty board-certified in Reproductive Endocrinology and Infertility (REI), and we are the only center in Nevada to have three board-certified (REI) physicians.

There are several other important factors to keep in mind when comparing IVF success rates.

• Single vs. multiple embryo transfer: The best centers have high implantation rates, giving them and their patients the confidence to achieve high pregnancy and birth rates with single embryo transfers. Some clinics transfer multiple embryos to boost their success rates, but this practice increases the chance of having a risky twin or triplet pregnancy. For example, in 2017, The Fertility Center of Las Vegas transferred an average of 1.0 embryos in patients under 35 years of age, while the national average was 1.3 embryos per transfer because some centers sacrificed safety in order to increase their birth rates per transfer by more often transferring multiple embryos.
• Own eggs vs. donor eggs: Some centers require patients with diminished ovarian reserve to use donor eggs. These clinics will have artificially higher success rates because donor eggs tend to produce higher success rates.  While the use of donor eggs can be an excellent choice for many, the Fertility Center of Las Vegas does not force this choice on patients with viable ovarian function, even if the ovarian reserve is diminished.
• Preliminary and final SART reports: The latest SART data are always “preliminary” because they do not include successful frozen embryo transfers in the following calendar year. This system counts failures immediately and defers many successes for one year. The “final” SART reports take one year longer to produce, but are more reliable, especially for clinics like FCLV that only do frozen transfers.

To learn more about IVF success rates at our Las Vegas fertility center or to schedule a personal consultation with one of our Las Vegas fertility experts, contact us.