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2004 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 12,
13, and
14, eggs produced by women in older
age groups form embryos that are less likely to implant and more likely
to spontaneously abort 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 2004 (15,175 cycles).
Figure 40 shows the percentage of ART cycles using donor eggs in
2004 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, about 91% of all ART cycles used donor eggs.
Figure 40: Percentage of ART Cycles
Using Donor Eggs, by ART Patient’s Age, 2004.
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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 41 compares live birth rates
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 live birth per transfer rate for cycles using
embryos from donor eggs varies only slightly across all age groups. The
average live birth per transfer rate is 51%. In contrast, the live birth
rates for cycles using embryos from women’s own eggs decline steadily as
women get older.
Figure 41: Live Births per Transfer
for ART Cycles Using Fresh Embryos from Own and Donor Eggs, by ART
Patient’s Age, 2004.
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How successful is ART when donor eggs are used?
Figure 42 shows live
birth per transfer rates and singleton live birth per transfer rates for ART
cycles using fresh embryos from donor eggs among women of different ages.
For all ages, the singleton live birth rates (average 30%) were lower than
the total live birth rates (average 51%). 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 42: Live Births per Transfer
and Singleton Live Births per Transfer for ART Cycles Using Fresh
Embryos from Donor Eggs, by ART Patient’s Age, 2004.
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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 43 shows that among the 5,449 pregnancies
that resulted from ART cycles using fresh embryos from donor eggs, about
53% were singleton pregnancies, about 37% 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 2004, 4,690 pregnancies
from ART cycles that used fresh embryos from donor eggs resulted in live
births. Part B of Figure 43
shows that 40% of these live births produced
more than one infant (about 38% 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. Triplet (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. Information on medical multifetal pregnancy
reductions is incomplete and therefore is not provided here.
Figure 43: Risk of Having
Multiple-Fetus Pregnancy and Multiple-Infant Live Birth from ART Cycles
Using Fresh Donor Eggs, 2004.
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How do success rates differ between women who use frozen
donor embryos and those who use fresh donor embryos?
Figure 44 shows that
the success rates per transfer for frozen donor embryos were
substantially lower than the success rates per transfer for fresh donor
embryos. This is similar to the findings for frozen nondonor embryos
(see Figure 38). 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 44: Success
Rates for ART Cycles Using Frozen Donor and Fresh Donor Embryos, 2004.
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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
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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