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.

 

 

 

 

 

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.

 

 

 

 

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.

 

 

 

 

 

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.

 

 

 

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.