Both CDC and Society for Assisted Reproductive Technologists (SART) maintain that head-to-head comparison between clinics is not meaningful without considering the patient population and the practice style. Following is just a few selected examples of how different practice style and patient population affect IVF success rates.
- How much effort does a clinic put into its non-IVF treatment program? Paradoxically, the more sloppy a clinic is with its non IVF program, the more likely it will be “rewarded” with patients with favorable prognosis for its IVF program. Ironically, there is more incentive for clinic to work less hard for its non IVF cycles.
- How willing are the patients of a particular clinic to go through more non-IVF treatment cycles? In other words, are the patients going through IVF in a particular clinic would have got pregnant without IVF in another clinic? This is dependent on the practice style of the clinic as well as the socioeconomics of the area where the clinic is located. Studies have shown IVF utilization is higher in states where there are mandated IVF insurance coverage. Many patients who have IVF coverage and successfully conceived through IVF would not have gone through IVF had they lived in a state without such coverage; or they might have conceived with less expensive non-IVF treatment.
- Does the clinic have an exclusion or selection process prior to IVF? A clinic that turns away patients with unfavorable prognostic test results will have a higher success rate than a clinic that has an all inclusive policy.
- What is the clinic’s stimulation philosophy? Generally the more gentle the stimulation, the lower number of mature follicles will result. A lower number of mature follicles yield less fertilized eggs, and less number of good quality embryos but at the same time result in less ovarian hyper-stimulation syndrome. Clinic that has a policy on more gentle stimulation or offers minimally stimulated protocols for cost saving or patient preference will have a lower live birth rate per cycle.
- What is the clinic’s cancellation policy? A clinic with a higher threshold requirement before proceeding with retrieval will have a higher success rate, e.g. if a clinic cancels all cycles with less than 3 mature follicles, it is likely to have a higher success rate than a clinic which does not have this cancellation criterion.
- What is the clinic’s policy on the number of embryos to transfer? Clinics vary in their value to avoid high order multiple gestations. Success rate alone does not reflect the percentage of high order multiple births.
- One simple way to check if a clinic over utilizes IVF is to compare its IVF success rate with its own donor oocyte program success. By definition, oocyte donors are fertile individuals and hence success rate of donor oocyte program serves as a bench mark that marks the highest possible success rate with IVF. If a clinic year after year has higher IVF success rate for its patients than its donor oocyte program, it is highly likely that their patients would have conceived with means other than IVF.