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2002 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 slightly more than 11% of all ART
cycles carried out in 2002 (13,183 cycles).
Figure 35 shows the percentage
of ART cycles using donor eggs in 2002 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
35: Percentage of ART Cycles Using Donor Eggs, by ART Patient's Age,
2002.
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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 36 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 50%. In contrast, the live birth rates for
cycles using embryos from women’s own eggs decline steadily as women get
older.
Figure
36: Live Births per Transfer for ART Cycles Using Fresh Embryos from
Own and Donor Eggs, by ART Patient's Age, 2002.
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How successful is ART when donor eggs are used?
Figure 37 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 29%) were
lower than the total live birth rates (average 50%). 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
37: Live Births per Transfer and Singleton Live Births per Transfer
for ART Cycles Using Fresh Embryos from Donor Eggs, by ART Patient's Age,
2002.
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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 38 shows that among the
4,854 pregnancies that resulted from ART cycles using fresh embryos from
donor eggs, about 51% were singleton pregnancies, about 38% were twins,
and nearly 7% were triplets or more. Slightly more than 4% 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 45%).
In 2002, 4,195 pregnancies from ART cycles that used fresh embryos from
donor eggs resulted in live births. Part B of
Figure 38 shows that slightly
more than 42% of these live births produced more than one infant (about
40% 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
38: Risk of Having Multiple-Fetus Pregnancy and Multiple-Infant Live
Birth from ART Cycles Using Fresh Embryos from Donor Eggs, 2002.
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How do success rates differ between women who use frozen
donor embryos and those who use fresh donor embryos?
Figure 39 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 33). 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
39: Success Rates for ART Cycles Using Frozen Donor and Fresh Donor
Embryos, 2002.
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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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