To the Editor:
We commend Kushnir et al. for their detailed analysis of the publicly available Society for Assisted Reproductive Technology (SART) report in the article “The status of public reporting of clinical outcomes in assisted reproductive technology” (1). SART continues to believe that any use of the ART report to make direct comparisons of outcomes between clinics is not valid and is inappropriate. The goal of the report is to facilitate reasonable estimation of the success rate at a given clinic. Unfortunately, recent evolution of clinical practice has made the reasonable estimation of success per cycle start much more difficult.
The exclusion of “banking” cycles from the denominator of the report is an unintended consequence of our common sense handling of true “fertility preservation” cycles. The outcomes report would be misleading if it included cycles with no intention for embryo transfer in the near future (for example, cycles conducted to obtain eggs or embryos prior to chemotherapy). SART has identified the need to distinguish fertility preservation from “short-term” banking. The indications for short-term banking (such as PGD, endometrial receptivity) are outlined in the manuscript; however, other indications for short-term banking exist (for example, risk for OHSS, polyps, etc.). We fully agree that the outcomes of these cycles should be accounted for in the Clinic Summary Report. The SART Registry Committee and SART Executive Council have discussed this at length, and we have sought input from our members. We do not believe that simply indicating the number of embryo banking cycles is adequate. SART has met with the Centers for Disease Control and Prevention (CDC), with whom we have a long-standing collaboration, to discuss what our options are for including banked cycles in outcome reports.
While one option, suggested by the authors, is reporting “total reproductive potential per initiated cycle including initial fresh and subsequent frozen embryo cycles,” (1) which has been discussed previously by the SART Executive Council, we have been unable to define this parameter satisfactorily. Moreover, final embryo transfer can occur years after egg retrieval, so calculation of rates will never be final.
We believe that the best solution to reporting short-term banked cycles is to “link” the initial stimulation cycle to the first or “primary” embryo transfer. Cycles without transfer (PGS cycles with no normal embryos) will now be accounted for. Linking cycles does have one disadvantage: the date of retrieval and primary embryo transfer may cross calendar years. SART has proposed to the CDC that a delay in the finalization deadline for 3 months from current dates is appropriate. This approach will allow the vast majority of cycles to be linked with a transfer outcome within a given reporting year.
We look forward to working with the CDC to construct a more accurate ART outcome report that takes into account recent changes in ART practice.
Kevin Doody, M.D., SART Registry Chair; G. David Ball, Ph.D., SART President; Glenn Schattman, M.D., SART Past President; Charles Coddington, III, M.D., SART President-Elect; James P. Toner, M.D., Ph.D., SART Vice President; and James Goldfarb, M.D., MBA, SART Public Affairs
1. Kushnir VA, Vidali A, Barad DH, Gleicher N. The status of public reporting of clinical outcomes in assisted reproductive technology. Fertil Steril. 2013 [Epub ahead of print]
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2013.07.1987
The authors respond:
We appreciate the constructive response to our manuscript by the leadership of the Society for Assisted Reproductive Technology (SART) (1), but would like to add several suggestions not fully addressed in our manuscript (2). Since assisted reproductive technology (ART) outcome reports are primarily intended for the public, they, even without statistical knowledge, should be interpretable by lay people. This means that biases and effects on reported pregnancy rates should become apparent to the public.
One way to achieve this is to track cycles prospectively and report outcomes based on intention to treat rather than per embryo transfer. This should also apply to cycles involving preimplantation genetic screening (PGS), which under the current system may be excluded from reporting if no embryos reach blastocyst stage, all embryos are banked/cryopreserved, or are found to be aneuploid and not transferred (3). Reporting ART outcomes based on intention to treat should, therefore, also be the reporting method of choice in clinical trials involving embryo banking and PGS. Reporting per embryo transfer, obviously, strongly selects patients with favorable prognosis and, therefore, does not permit average patients to gauge true chances of success.
Reporting of total reproductive potential (TRP) per initiated cycle, including initial fresh and subsequent frozen/thawed cycles, is an additional option to improve transparency, and is feasible as recently demonstrated utilizing the SART dataset (4). A preliminary calculation of TRP after a short grace period of about 3 months following a fresh cycle, may indeed be sufficient to incorporate outcomes of a vast majority of short-term embryo banking cycles into the calculation of TRP and, thereby, offer additional transparency to the public.
Although the ART reporting system was not intended to be used by the public to directly compare outcomes between centers, it is widely used this way. In recognition of this fact it may now be appropriate to improve the system by stratifying patients by severity of their condition more thoroughly to reflect differences in patient populations among centers. This means that patients should be stratified not only by age but also by functional ovarian reserve and other prognosticators of ART success.
Vitaly A. Kushnir, M.D., Andrea Vidali, M.D., David H. Barad, M.D. M.S., and Norbert Gleicher, M.D.
Center for Human Reproduction (CHR) (V.A.K, D.H.B., N.G.)
New York Reproductive Services (A.V.)
Foundation for Reproductive Medicine (D.H.B., N.G.)
New York, New York
1. Doody K, Ball GD, Schattman G, Coddington C, Toner JP, Goldfarb J. Letter to the Editor, Fertil Steril. 2013 (in press)
2. Kushnir VA, Vidali A, Barad DH, Gleicher N. The status of public reporting of clinical outcomes in assisted reproductive technology. Fertil Steril 2013 Jun 8. doi:pii: S0015-0282(13)00610-9. 10.1016/j.fertnstert.2013.05.012.
3. Gleicher N, Barad DH. A review of, and commentary on, the ongoing second clinical introduction of preimplantation genetic screening (PGS) to routine IVF practice. J Assist Reprod Genet 2012;29:1159-66.
4. Stern JE, Hickman TN, Kinzer D, Penzias AS, Ball GD, Gibbons WE. Can the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) be used to accurately report clinic total reproductive potential (TRP)? Fertil Steril 2012; 97:886-9.
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2013.07.1990