Introduction to Fertility Clinic Tables
The national summary table combines data from all clinics. Individual clinic tables contain each clinic’s data presented in a one-page table that includes the types of assisted reproductive technology (ART) used, patient diagnoses, success rates that each clinic reported and verified for 2009, and individual program characteristics.
Many people considering ART will want to use this report to find the “best” clinic. However, comparisons between clinics must be made with caution. Many factors contribute to the success of an ART procedure. Some factors are related to the training and experience of the ART clinic and laboratory professionals and the quality of services they provide. Other factors are related to the patients themselves, such as their age and the cause of their infertility. Some clinics may be more willing than others to accept patients with low chances of success or may specialize in various ART treatments that attract particular types of patients. These and other factors to consider when interpreting clinic data are discussed below.
- These statistics are for 2009. Data for cycles started in 2009 could not be published until 2011 because the final outcomes of pregnancies conceived in December 2009 were not known until October 2010. Additional time was then required to collect and analyze the data and prepare the report. Many factors that contribute to a clinic’s success rate may have changed in the 2 years since these procedures were performed. Personnel may be different. Equipment and training may or may not have been updated. As a result, success rates for 2009 may differ from current rates.
- No reported success rate is absolute. A clinic’s success rates vary from year to year even if all determining factors remain the same. The more cycles that a clinic carries out, the less the rate is likely to vary. Conversely, clinics that perform fewer cycles are likely to have more variability in success rates from year to year. As an extreme example, if a clinic reports only one ART cycle in a given category, as is sometimes the case in the data presented here, the clinic’s success rate in that category would be either 0% or 100%. For further detail, see the explanation of confidence intervals.
- Some clinics see more than the average number of patients with difficult infertility problems. Some clinics are willing to offer ART to most potential users, even those who have a low probability of success. Others discourage such patients or encourage them to use donor eggs, practices that result in higher success rates among older women. Clinics that accept a higher percentage of women who previously have had multiple unsuccessful ART cycles will generally have lower success rates. In contrast, clinics that offer ART procedures to patients who might have become pregnant with less technologically advanced treatment will have higher success rates.
A related issue is that success rates shown in this report are presented in terms of cycles, as required by law, rather than in terms of women. As a result, women who had more than one ART cycle in 2009 are represented in multiple cycles that cannot be linked. If a woman who underwent several ART cycles at a given clinic either never had a successful cycle or had a successful cycle only after numerous attempts, the clinic’s success rates would be lowered.
- Cancellation percentages affect a clinic’s success rate. Percentages of cancelled cycles using fresh nondonor eggs or embryos vary among clinics from less than 1% to, in a few cases, more than 30%. A high percentage of cancellations tends to lower the percentage of cycles resulting in live births but may increase the percentage of retrievals resulting in live births and the percentage of transfers resulting in live births.
- Percentages of unstimulated (or “natural”) cycles are included with those for stimulated cycles. In an unstimulated cycle, the woman ovulates naturally rather than through the daily injections used in stimulated cycles. Unstimulated cycles are less expensive because they require no daily injections and fewer ultrasounds and blood tests. However, women who use natural or mild stimulation produce only one or two follicles, thus reducing the potential number of embryos for transfer. As a result, clinics that perform a relatively high percentage of unstimulated cycles may have lower success rates. Nationally, fewer than 1% of ART cycles using fresh nondonor eggs or embryos in 2009 were unstimulated. In a very few clinics, more than 2% of cycles were unstimulated.
- Success rates are calculated per cycle rather than per patient. Therefore, for patients who undergo both fresh and frozen cycles, success rates are calculated separately for each cycle. Clinics that have a very high percentage of cycles resulting in live births with frozen embryos would have higher ART success rates if these births were included as successes from the original stimulated cycle. Consumers should look at both rates (for cycles using fresh embryos and for those using frozen embryos) when assessing a clinic’s success rates.
- The number of embryos transferred varies from clinic to clinic. In 2009, the average number of embryos that a clinic transferred to women younger than age 35 ranged from one to four for fresh nondonor cycles. The American Society for Reproductive Medicine and the Society for Assisted Reproductive Technology discourage the transfer of a large number of embryos because it increases the likelihood of multiple-fetus pregnancies. Multiple-fetus pregnancies, in turn, increase the probability of premature births and their related problems.
In addition, success rates can be affected by many other factors, including
- Quality of eggs.
- Quality of sperm (including motility and ability to penetrate the egg).
- Skill and competence of the treatment team.
- General health of the woman.
- Genetic factors.
We encourage consumers considering ART to contact clinics to discuss their specific medical situations and their potential for success using ART. Because clinics did not have the opportunity to provide narratives to explain their data, such conversations could provide additional information to help people decide whether to use ART.
Although ART offers important options for the treatment of infertility, the decision to use ART involves many factors in addition to success rates. Undergoing repeated ART cycles requires substantial commitments of time, effort, money, and emotional energy. Therefore, consumers should carefully examine all related financial, psychological, and medical issues before beginning treatment. They also will want to consider the location of the clinic, the counseling and support services available, and the rapport that staff members have with their patients.