Understanding IVF Success Rates

As you begin your fertility journey, it is helpful to know the success rates of reproductive clinics. Knowledge about the total number of births per cycle, or births with donor eggs can prove helpful when deciding which clinic to use.

In the United States, all fertility clinics are mandated to report their success rates to the Centers for Disease Control and Prevention (CDC) but many clinics also voluntarily report data to the Society for Assisted Reproductive Technology (SART). Here is a guide to help you better understand the information presented in SART.

Benefits of Reporting to SART

SART collects detailed information from clinics, audits the information, and presents the information to patients in a thorough transparent fashion. In fact, SART engages a third-party agency to audit clinics to make sure that the information presented is accurate and precise.

The world of Assisted Reproductive Technologies and In Vitro Fertilization (IVF) has become increasingly complicated, and presenting realistic expectations to patients has become an essential function of the Society.

How SART Data is Presented

Success rates are presented in two types of SART Clinical Summary Reports (CSRs). The national CSR displays data from all reporting clinics, allowing patients to see national success rates broken out by category, while clinic-specific reports contain data from just one clinic.

A successful IVF treatment results in the birth of a single full term healthy baby. This goal is achieved by combining optimal treatment and the most up to date technology. SART recently redesigned its report to include new practices such as embryo cryopreservation (embryo freezing), genetic testing, and elective single embryo transfer (eSET). Success is reported for all cycles that are initiated and then again for completed cycles.

What is a Cycle?

A cycle is defined as the time when a woman has started medications for the purpose of having an IVF procedure. For those women who do not need medications, the cycle is defined as the first day of her menstrual cycle when she is planning to have a procedure done that month. Each cycle is counted when calculating the pregnancy rate. Counting each cycle rather than each embryo transfer, more accurately reflects the treatment burden and costs the patient has to potentially endure.

Cycles, however, may be cancelled and never get to completion. A cycle may be cancelled because of an inadequate egg supply, poor embryo and/or uterine lining development, or because the embryos were frozen and intended to be implanted at a later time. Clinics that cancel cycles prior to egg retrieval will bias the results and display higher success rates since patients with poor prognosis will be excluded. Patients should review the cancellation rates for other patients their age to understand the chance of successfully completed a cycle of IVF at that clinic.

Success Rate Categories and What They Mean – 

Patient’s own eggs

Data in this category is from patients undergoing IVF using their own eggs. This accounts for the majority of IVF cycles performed each year, and it is broken down further into the following:

  • Cumulative outcome per egg retrieval cycle: Overall rate of success for an IVF cycle including all rounds of embryo transfers. The “cumulative live birth rate,” signifies the percentage of successful birth outcomes after a year of initiating an IVF cycle.
  • Primary outcome: Results from the first embryo transfer.
  • Subsequent outcome (frozen cycles): Results from ongoing embryo transfers.
  • Live birth per new patient: Success rates for patients who are new to the clinic for the given reporting year.

Donor Eggs & Embryos

Data in this category is gathered from patients who underwent a round of IVF treatment using donor eggs or embryos and is broke down further into the following:

  • Fresh donor eggs: Success rates for patients using non-frozen donor eggs.
  • Frozen donor eggs: Success rates for patients using frozen donor eggs.
  • Thawed embryos: Success rates for patients using thawed donor embryos that had been frozen.
  • Donated embryos: Success rates for all donor embryo cycles.

Using Advanced Treatments to Increase Success

To increase the chances of achieving a successful pregnancy, especially in women over 40, it is important to have information about the embryo’s genetic makeup. Advanced clinics offer preimplantation genetic testing (PGT), which is the ability to biopsy a few cells from the blastocyst stage of the embryo and test the genetic competence. In some cases this information may not be available until the next cycle so there may be no pregnancy from the retrieval cycle and the pregnancy will occur in a subsequent cycle after the embryos are frozen. The use of PGT will be reflected in a high pregnancy rate per transfer with a low pregnancy rate per cycle initiated. Programs that routinely perform PGT can have high cancellation rates, but exceptional rates per transfer because only normal embryos are transferred.

What this Data Means for you as a Patient

The statistics reported by SART offer a window into a clinic’s success. The number of cycles performed the willingness to take on tough cases, and the goal of transferring single embryos by assessing embryos for genetic competence and achieving a healthy baby at term are all factors you should consider when choosing an IVF center.

By RMA of NY