The way that we present our
success rates is by using the standardized method as outlined by SART
(Society of Assisted Reproductive Technologies), which is the
statistical record keeper of ART success rates under the American
Society of Reproductive Medicine. Even SART
realizes that certain clinics’ success rates are not comparable due to
the practices mentioned above as they qualify their statistical
summations with the statement “a comparison of clinic success rates may
not be meaningful because patient medical characteristics and treatment
approaches vary from clinic to clinic.” While it is
true that every clinic has its own treatment approaches, at GYFT, we do
not exclude patients on the
basis of age or type of infertility from attempting treatment just so
we can inflate our success rates.
Following is a brief
explanation of how to interpret the data in the success rate reports,
while clicking the links at left will let you view recent year reports
as published by SART.
By perusing the success
rate reports, you’ll see that age is the only categorizing
variable in determining the success of an IVF cycle. In
all honestly, there are innumerous variables which could be used to
categorize success rates including type of infertility, severity of
infertility, number of embryos transferred, quality of embryos
transferred, number of follicles produced, preparedness of the uterine
lining, ethnicity, weight, and so on. Because every
infertility patient has a unique set of circumstances pertaining to
their difficulty in getting pregnant, it’s quite impossible to quote a precise
probability of success for any particular couple. As
a result, the data is easier to understand if we group all variables
into one large pool of patients when calculating IVF success rates.
We then assess the likelihood of
pregnancy for any given couple based on the single factor of age – a
factor which is one of the more telling in predicting infertility.
This all-inclusive data, then,
will include patients with severe infertility issues as well as those
with fairly mild infertility issues. So, depending
on the nature of your particular situation, your chance of success may
be better or worse than the “averaged” rates outlined in the success
rate reports.
Looking at the reports, the
Program Profile is the section you will see first. It
basically summarizes the characteristics of our ART services:
We are a member of The Society for
Assisted Reproductive Technologies, we offer our ART services to single
women, we support the use of surrogates in ART if needed, and thus far
have not had an instance where donor eggs were shared between
recipients (this is because almost without fail, when a couple goes to
the expense to use donor eggs, they want all the available eggs for
themselves to maximize their chance at pregnancy). In
the Type of ART Used section, you can see that our energies are
exclusively devoted to IVF techniques with about one-third of our IVF
cases involving the use of ICSI (most commonly due to male factor
infertility). GIFT and ZIFT are procedures which,
in the past, had better success rates in certain situations but have
since been surpassed in all regards by the current methods of IVF and
are now rarely performed in the U.S. The ART
Patient Diagnosis block simply shows the types of infertility which we
currently treat using IVF.
Now let’s look at the data
in the Success Rates section. The largest block of
data describes the cycles using fresh embryos. Cycles
in which frozen embryos are thawed and transferred are described in a
smaller section below. As mentioned earlier, data is broken down into
four age groups: less than 35, 35 to 37, 38 to 40 and greater than 40.
Pregnancies per cycle
answers the question, “What are my chances of getting pregnant once I
start an IVF cycle?” A pregnancy is defined as
having an initial positive serum pregnancy test followed by
ultrasound-confirmed presence of an intrauterine gestational sac.
Live births per cycle
answers a slightly different question, “What are my chances of
delivering a healthy baby once I start an IVF cycle?” Notice
that this number differs from the number in the column above due to the
fact that not all established pregnancies as defined above will result
in a live birth because of the unfortunate inevitability that
miscarriages do in fact occur. So, although it can
be difficult to assess one patient’s miscarriage rate over another’s, a
woman who believes she is at less risk for miscarriage may have a live
birth rate closer to that of the pregnancies per cycle rate, while a
woman who believes she is at higher risk for miscarriage may have a
live birth rate which is lower.
The live births per retrieval
and per transfer are kept track of because not all patients
who start a cycle get as far as the retrieval and embryo transfer.
Thus, because there are
historically more starts than retrievals and more retrievals than
transfers, the live birth rate rises with each subsequent step of the
treatment process that a couple completes. In
recent years, however, the difference between the live births per
retrieval rate and the live births per transfer rate is negligible
since nearly 100% of patients who have a retrieval here at GYFT will
have an embryo transfer as well. Being able to tell
couples with certainty that they will have embryos returned to them
following an egg retrieval bolsters patient confidence in our program
because of our ability to obtain fertilization and embryonic
development in nearly all situations.
There usually is
a difference between the per cycle and per retrieval
rates, however. This is known as the cancellation
rate. Cancellations are cycles which are started
but halted at your doctor’s discretion prior to egg retrieval.
Sometimes, once a woman has begun
taking her medications and started being monitored, she may fail to
respond properly or just not respond well enough to justify the expense
of continuing with the current cycle when a better outcome is believed
to be attainable by your physician. Keep in mind
that the bulk of the expense for IVF is in the medications and the
processes following and including the egg retrieval. Thus,
it is sometimes in the patient’s best interest to concede a cycle by
having it cancelled prior to the retrieval and putting those funds
toward another attempt should the clinical staff determine that the
current cycle has too poor a prognosis. Not
surprisingly, cancellations tend to occur more frequently as the age of
the woman increases. In younger women (<35),
it’s typical for about 1 in every 20 cycles starts to get cancelled
while women 40 and over tend to have more like a 1 in every 7 to 8
cycle cancellations.
The next line on the
success rate report shows the average number of embryos that were
transferred per patient. See the Embryo Transfer section above for
discussion of the rationale for determining the number of embryos to
transfer.
The final line shows the
percentage of pregnancies resulting in a multiple pregnancy.
Historically here at GYFT, you can
expect a twin pregnancy to occur roughly once in every 4 pregnancies
and triplets roughly once in every 15 pregnancies. Multiples
tend to be more common the younger the female patient.
The last section entitled
“Cycles Using Donor Eggs” describes the outcomes of all IVF cycles in
which donor eggs were utilized. You’ll notice that
most donor egg cycles take place in the over 40 age group, often
because women in this age group are more likely to be poor responders,
have inadequate numbers of eggs in their ovarian reserves, or have
inferior quality eggs in their reserves. Using
donor eggs allows such a woman to significantly improve her odds of
achieving a pregnancy by allowing us to obtain a greater number and
better quality of eggs than she could produce on her own. Incidentally,
donor egg cycles account for most of the pregnancies in the over 40 age
group.
We hope you are now able to
navigate and comprehend the data in these reports. We
also hope you find the information encouraging as well, as we are quite
proud of how we’ve been able to maintain highly successful results from
one year to the next. And know that it is our
mission to constantly employ the latest technologies and quality
control procedures available to us in order to improve on our success
whenever possible.
