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2005 Assisted Reproductive Technology (ART) Report: Section 4—ART
Cycles Using Donor Eggs |
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Are older women undergoing ART more likely to use donor
eggs or embryos?
As shown in
Figures 14–16,
eggs produced by women in older age groups form embryos that are less
likely to implant and more likely to result in miscarriage if they do
implant. As a result, ART using donor eggs is much more common among
older women than among younger women. Donor eggs or embryos were used in
approximately 12% of all ART cycles carried out in 2005 (16,161 cycles).
Figure 44 shows the percentage of
ART cycles using donor eggs in 2005 according to the woman’s age. Few
women younger than age 39 used donor eggs; however, the percentage of
cycles carried out with donor eggs increased sharply starting at age 39.
Among women older than age 47, for example, about 90% of all ART cycles
used donor eggs.
Figure 44: Percentage of ART Cycles
Using Donor Eggs, by ART Patient’s Age, 2005.
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Do success rates differ by age for women who used ART
with donor eggs compared with women who used ART with their own eggs?
Figure 45 compares percentages of
transfers resulting in live births for ART cycles using fresh embryos
from donor eggs with those for ART cycles using a woman’s own eggs,
among women of different ages. The likelihood of a fertilized egg
implanting is related to the age of the woman who produced the egg. Egg
donors are typically in their 20s or early 30s. Thus, the percentage of
transfers resulting in live births for cycles using embryos from donor
eggs varies only slightly across all age groups. The average percentage
of transfers resulting in live births for cycles using embryos from
donor eggs is 52%. In contrast, the percentage of transfers resulting in
live births for cycles using embryos from women’s own eggs declines
steadily as women get older.
Figure 45: Percentages of Transfers
That Resulted in Live Births for ART Cycles Using Fresh Embryos from Own
and Donor Eggs, by ART Patient’s Age, 2005.
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How successful is ART when donor eggs are used?
Figure 46 shows
percentages of transfers resulting in live births and singleton live births
for ART cycles using fresh embryos from donor eggs among women of different
ages. For all ages, the percentage of transfers resulting in singleton live
births (average 31%) was lower than the percentage of transfers resulting in
live births (average 52%). Singleton live births are an important measure of
success because they have a much lower risk than multiple-infant births for
adverse infant health outcomes, including prematurity, low birth weight,
disability, and death.
Figure 46: Percentages of Transfers
That Resulted in Live Births and Singleton Live Births for ART Cycles
Using Fresh Embryos from Donor Eggs, by ART Patient’s Age, 2005.
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What is the risk of having a multiple-fetus pregnancy or
multiple-infant live birth from an ART cycle using fresh donor eggs?
Multiple-infant births are associated with greater
problems for both mothers and infants, including higher rates of
caesarean section, prematurity, low birth weight, and infant disability
or death.
Part A of Figure 47
shows that among the 5,877 pregnancies that resulted from ART cycles
using fresh embryos from donor eggs, about 53% were singleton
pregnancies, about 38% were twins, and nearly 5% were triplets or more.
About 5% of pregnancies ended in miscarriage before the number of
fetuses could be accurately determined. Therefore, the percentage of
pregnancies
with more than one fetus might have been higher than what was reported
(about 42%).
In 2005, 5,043 pregnancies from ART cycles that used
fresh embryos from donor eggs resulted in live births. Part B of
Figure 47 shows that 41% of these
live births produced more than one infant (about 39% twins and about 2%
triplets or more). This compares with a multiple-infant birth rate of
slightly more than 3% in the general population.
Although the total rates for multiples were similar for
pregnancies and live births, there were more triplet-or-more pregnancies
than births. Triple-or-more pregnancies may be reduced to twins or
singletons by the time of birth. This can happen naturally (e.g., fetal
death), or a woman and her doctor may decide to reduce the number of
fetuses using a procedure called multifetal pregnancy reduction. CDC
does not collect information on multifetal pregnancy reductions.
Figure 47: Risks of Having
Multiple-Fetus Pregnancy and Multiple-Infant Live Birth from ART Cycles
Using Fresh Embryos from Donor Eggs, 2005.
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How do success rates differ between women who use frozen
donor embryos and those who use fresh donor embryos?
Figure 48 shows that
the success rates resulting from the transfer of frozen donor embryos
were substantially lower than the success rates resulting from the
transfer of fresh donor embryos. This is similar to the findings for
frozen nondonor embryos (see Figure 42).
The average number of embryos transferred was similar for cycles using
frozen donor embryos and those using fresh donor embryos. (See the
national summary table for information on the
average number of embryos transferred for these cycles.)
Figure 48: Success
Rates for ART Cycles Using Frozen Donor and Fresh Donor Embryos, 2005.
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Section
1 | Section 2 |
Section
3 | Section 4 |
Section
5
Previous ART Reports
Implementation of the Fertility
Clinic Success Rate and Certification Act of 1992
Assisted Reproductive Technology: Embryo
Laboratory
Page last reviewed: 12/12/07
Page last modified: 12/12/07
Content source: Division
of Reproductive Health,
National Center for Chronic Disease
Prevention and Health Promotion
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