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2004 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 2004, 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
- These statistics are for 2004. Data for cycles
started in 2004 could not be published until 2006 because the final
outcomes of pregnancies conceived in December 2004 were not known
until October 2005. 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 2004 may differ
from current rates.
- 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.
- 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 2004 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.
- 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 about 41%. 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.
- 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 2004 were unstimulated. In a very few
clinics, more than 1%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 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.
- The number of embryos transferred varies from clinic to
clinic. In 2004, the average number of embryos that a clinic
transferred to women younger than age 35 ranged from two to six 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
- 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. 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.
Explanation of how to read a fertility clinic
table.
Previous ART Reports
Implementation
of the Fertility Clinic Success Rate and Certification Act of 1992
Assisted
Reproductive Technology: Embryo Laboratory
Date last reviewed:
01/14/2007
Content source: Division
of Reproductive Health,
National Center for Chronic Disease
Prevention and Health Promotion
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