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2001 Assisted Reproductive
Technology (ART) Report: Introduction to Fertility Clinic Tables |
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The first table in this section is the national summary
of combined data from all clinics. Individual clinic tables follow, with
each clinic’s data presented in a one-page table that includes the types
of ART used, patient diagnoses, success rates that each clinic reported
and verified for 2001, and individual program characteristics. Clinics
are listed in alphabetical order by state, city, and clinic name.
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.
Important Factors to
Consider When Using These Tables to Assess a Clinic
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These statistics are for 2001. Data for
cycles started in 2001 could not be published until 2003 because the
final outcomes of pregnancies conceived in December 2001 were not
known until October 2002. 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, for better or
for worse, 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 2001 may differ from
current rates.
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No reported success rate is absolute. A
clinic’s success rates will vary from year to year even if all
determining factors remain the same. However, the more cycles that a
clinic carries out, the less the rate is likely to vary. Conversely,
clinics that carry out 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.
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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, a practice that results 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 2001
are represented in multiple cycles. 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.
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Cancellation rates affect a clinic’s success
rate. Cancellation rates for cycles using fresh nondonor eggs
or embryos vary among clinics from less than 1% to approximately 42%.
A high cancellation rate tends to lower the live birth per cycle rate
but may increase the live birth per retrieval rate and the live birth
per transfer rate.
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Success rates for 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, unstimulated
cycles are less successful, and clinics that carry out a relatively
high proportion of unstimulated cycles will have lower success rates.
Nationally, fewer than 1% of ART cycles using fresh nondonor eggs or
embryos in 2001 were unstimulated. However, in a very few clinics,
more than 10% of cycles were unstimulated.
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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 very good live birth rates 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.
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The number of embryos transferred varies from
clinic to clinic. In 2001, the average number of embryos that
a clinic transferred to women younger than age 35 ranged from one to
five 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 gestations. Multiple gestations,
in turn, increase both the probability of premature birth and its
related problems and the need for multifetal pregnancy reductions.
In addition, success rates can be affected by many other
factors, including
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the quality of eggs.
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the quality of sperm (including motility and ability to
penetrate the egg).
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the skill and competence of the treatment team.
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the general health of the woman.
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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. Going through 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.
See an explanation of how to read a fertility clinic
table for more information.
Previous ART Reports
Implementation of the Fertility
Clinic Success Rate and Certification Act of 1992
Assisted Reproductive Technology: Embryo
Laboratory
Date last reviewed:
03/23/2006
Content source: Division
of Reproductive Health,
National Center for Chronic Disease
Prevention and Health Promotion
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