Understanding SART and CDC IVF Success Rate Data

How to make sense of the Assisted Reproductive Technology (ART) Report.

The statistics provided in a fertility clinic's IVF success rate report can tell you a lot about that practice. Here are a few helpful tips on what to look for and what it may mean to you.

Total IVF Cycles Performed Per Year

Total IVF Cycles Reported

First you may want to verify that a fertility clinic is doing a good number of IVF cycles a year. You want a clinic that is proficient and experienced in the art of IVF. 120 total IVF cycles or more in one year is a good number. That means that they average more than 2 cycles a week, which gives you an indication that they routinely perform IVF procedures.

Fresh Embryos From Non-Donor Oocytes

Fresh Embryos From Non-Donor Oocytes

The group of patients counted here are couples who engaged in IVF using a fresh cycle. A fresh cycle means that their eggs were taken from the ovaries and inseminated in the embryology lab of the clinic,  put in an incubator to mature and then implanted back into the uterus. In these cycles, the embryologist or doctor picks out the best looking of the matured embryos to put back into the woman's uterus. The ones that show healthy development and look great under the microscope have the highest chance of implantation and pregnancy.

These cycles do not include the freezing and thawing that happens to the "leftover" embryos. Couples can use frozen embryos in a second try, but a lot of mishandling can happen during the freezing and thawing process and success rates are lower for the thawed embryos.

Of course, if you are evaluating a clinic for frozen transfer or will be using donor eggs, then you will want to focus on those numbers.

Success Rates By Age Group

Success Rates By Age Group

Younger than 35: Statistically, the highest chance of IVF success.
35-37: Still statistically favorable for a successful IVF outcome.
38-40: This segment shows the real talent of a fertility clinic
41 and beyond: This is an age category, where fertility doctors either tend to recommend egg donation or take on the challenges and perform IVF. Based on the number of cycles performed in this segment, you can tell the type of doctor you are evaluating. Low numbers (below 10) shows you that he/she tends to recommend egg donation to older women. High numbers (10 and more) shows you that they are confident enough to lead this age group through IVF despite the odds. 

Obviously the most relevant numbers are the one that correspond to your particular age group.

Percentage of transfers resulting in live births

Percentage of transfers resulting in live births

This is the most important number for your age group. It tells you how many cycles with transfers resulted in a baby. Sometimes there is an egg retrieval, but no transfer of the embryo(s). Sometimes an IVF cycle gets started, but cancelled for whatever reason. All of those scenarios are excluded in this number.

Every cycle that was completed has to have an embryo transfer. The percentage of transfers resulting in live births is the best way to evaluate a fertility clinic's IVF success rate. That being said, there are ways that the IVF data can be manipulated and you should consider this before you make your final decision.

Success rates are listed as a fraction when the total number of cycles in a segment is less than 20. SART and the CDC feel that with a low number of total cycles, success rates expressed as a percentage are too unreliable. For instance a clinic that performed a single cycle would have either a 100% or 0% success rate.

For a complete explanation of this please see the Latest CDC Assisted Reproductive Technology (ART) Report.

We have factored out any clinics with less than 20 cycles in a segment in our Comparative IVF Success Rate Report. However, we have provided success rate as a percentage on individual clinic report pages on this site regardless of the number of cycles. Please evaluate total number of cycles per segment when evaluating IVF success rates.

Average Number of Embryos Transferred

Average Number of Embryos Transferred

This can vary from age group to age group, and it strongly depends on the physician and your diagnosis. The national average is 2.3 embryos in the age groups up to 37 years old in 2006. This number should continue to decrease over time as IVF technology gets better.

The transfer of multiple embryos increases pregnancy success, but also increases the risk of multiple births. There was a study in 2005 that showed that birth rates are nearly the same with single embryo transfer instead of two-embryo transfer (Fertility & Sterility, December 2005). Also, in 2006 the ASRM revised their guidelines for the number of embryos to transfer to protect couples. The new guidelines recommend that no more than two embryos should be transferred for a woman under the age of 35 under normal circumstances. In fact, with the best diagnosis a woman age 35 or younger undergoing a fresh IVF cycle should be offered a single embryo transfer by her fertility doctor Read for yourself in this 2-page document published by ASRM: http://www.asrm.org/Media/Practice/Guidelines_on_number_of_embryos.pdf).

If your doctor recommends transferring more than what ASRM recommends for your age group, ask for a complete explanation to justify the higher number of embryos.

For complete reports provided by SART please visit http://www.sart.org.

For complete reports provided by the CDC please visit http://www.cdc.gov/ART/

Wondering why there are two different reports for IVF success rate data? Check our IVF Success Rates Frequently Asked Questions

Compare and review current IVF success rates.

Tags:

3 Responses to “Understanding SART and CDC IVF Success Rate Data”

  1. [...] jeopardized in the pursuit of high success rates. Again, the real answer to this valid point is to educate patients on the importance of Average Number of Embryos Transfered, and Percentage of High Order Multiples. [...]

  2. [...] we cover similar information here, it was great to see such a detailed and informative article posted by a young [...]

  3. [...] I also like this site, Fertility Success Rates , for comparing clinics side-by-side. Top clinics are reported here in a list. You can read some of the caveats about interpreting success rates here. [...]

Leave a Reply