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Quick Jumps:
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The
following data includes 1/1/96 - 12/31/2000 data. Some of the
2000 pregnancies are still ongoing, although all have passed well
into their second and third trimesters. To remain accurate,
however, the statistics are described as Delivered/Ongoing
Pregnancy Rates per Embryo Transfer Procedure.
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We
know that ART has a known risk of multiple pregnancy. We are
always trying to balance our desire your pregnancy against the
risks of multiple pregnancy. No question, the fewer embryos we
transfer, the fewer multiple pregnancies that occur. Unfortunately,
the fewer the embryos transferred, the lower the overall
success rates. It's a difficult balance.
Below
are the delivered/ongoing multiple pregnancy rates for SRMS. In this section, we
elected to combine 1996 through 12/31/2000 data:
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A
great deal of very interesting information can be derived from the
above data:
- Once pregnant, the chance
for a multiple pregnancy was 52% (54/103).
- If with a multiple
pregnancy, the vast majority were twins (80%, 43/54)
while a significant minority were triplets (20%, 11/54).
- Once pregnant though ART,
the chance of having twins was 42% (43/103).
- Once pregnant through
ART, the chance of having triplets was 11% (11/103).
In
1998, the CDC published the national multiple pregnancy live
birth rates
for ART using fresh embryo transfers from non-donor oocytes:
- Singleton pregnancies
occurred 61% of the time.
- Multiple pregnancies occurred
39% of the time.
- 84% of the multiples were
twins
- 16% of the multiples were
triplets or more.
Our
data included egg donation, so the statistics were not
completely comparable. Even so, I believe the following
statements can be made:
- Once pregnant, our multiple pregnancy
rates (53%) were higher than the national average (39%).
- We transferred fewer
embryos per embryo transfer procedure (2.9 embryos with
our 1997-2000
data) compared to the roughly estimated 1997 reported data
of 3.8 embryos per transfer procedure. I am sorry that I
couldn't report the national 1998 data. It just simply was
not available. It would appear, however, that we were more efficient
with the embryos that we did transfer compared to the
available national statistics.
- Once multiple pregnancies occurred,
our overall twin and triplet rates were quite similar to
the national average.
We
continue to try to reduce our multiple pregnancy rates while maintaining
a very high success rate. It is a tricky balance.
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The
key to reduce multiple pregnancies is to transfer fewer
embryos. Trying
to decide how many embryos to transfer requires a knowledge of
the implantation rate per embryo transferred. The implantation
rate per embryo transferred is the number of gestational
sacs identified by ultrasound divided by the total number of
embryos placed into the uterus.
Our
goal was to transfer fewer embryos, but make those embryos that we did
transfer more likely to implant. It would appear that we accomplished
these goals (IVF data provided):
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Pending review. |
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In
spite of this drop in the average numbers of embryos
transferred, our multiple rates essentially remained the same
or even slightly increased. This meant that the quality of the
embryos that we were transferring improved over time. I can
assure you that the patients were not getting any easier.
Instead, the laboratory and embryo transfer techniques should
probably be given the credit for the improved implantation
rates.
If we further reduce the number of embryos
we transfer, we will run the risk of decreasing the
take-home-baby-rates. It is a tough decision. Until
we get comprehensive infertility insurance coverage, we will
continue to try
to balance our strong desire for success while trying to
minimize the multiple pregnancy rates.
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Below
are additional links on this web site that may be of
particular interest to the reader regarding Multiple
Pregnancy:
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