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2003 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 10,
11, and
12, 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 2003 (14,323 cycles).
Figure 38 shows the percentage
of ART cycles using donor eggs in 2003 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 45, about 77% of all ART cycles used donor
eggs.
Figure
38: Percentage of ART Cycles Using Donor
Eggs, by ART Patient's Age, 2003.
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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 39 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
39: Live Births per Transfer for ART Cycles Using Fresh Embryos from
Own and Donor Eggs, by ART Patient's Age, 2003.
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How successful is ART when donor eggs are used?
Figure 40 shows
live birth per transfer rates and singleton live birth per transfer rates
for ART procedures 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
40: Live Births per Transfer and
Singleton Live Births per Transfer for ART Cycles Using Fresh Embryos from
Donor Eggs, by ART Patient's Age, 2003.
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What is the risk of having a multiple-fetus pregnancy or
multiple-infant 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 41
shows that among the 5,271 pregnancies that resulted from ART cycles using
fresh embryos from donor eggs, about 53% were singleton pregnancies, about
36% were twins, and nearly 7% 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 43%).
In 2003, 4,554 pregnancies from ART cycles that used fresh
embryos from donor eggs resulted in live births. Part B of
Figure 41 shows that slightly
more than 40% of these live births produced more than one infant (about 38%
twins and about 3% 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 pregnancies than
triplet 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
41: Risk of Having Multiple-Fetus Pregnancy and Multiple-Infant Live
Birth from ART Cycles Using Fresh Donor Eggs, 2003.
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How do success rates differ between women who use frozen
donor embryos and those who use fresh donor embryos?
Figure 42 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 36). 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
42: Success Rates for ART Cycles Using Frozen Donor and Fresh Donor
Embryos, 2003.
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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:
03/27/2006
Content source: Division
of Reproductive Health,
National Center for Chronic Disease
Prevention and Health Promotion
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