Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Section 2: ART Cycles Using Fresh, Nondonor Eggs or Embryos (Part C)

Section 2 it is broken up into three parts. Part C contains Figures 26–34.

Is the percentage of transfers that result in a good perinatal outcome affected by the number of embryos transferred?

Figure 26 shows the relationship between the number of fresh nondonor eggs or embryos transferred and a good perinatal outcome among ART cycles performed in 2011 that resulted in the transfer of one or more embryos. A good perinatal outcome is defined as the live birth of a singleton infant at 37 or more full weeks of pregnancy and with a normal birth weight of more than 2,500 grams (5 pounds, 9 ounces). The percentage of transfers resulting in a good perinatal outcome decreased as the number of embryos transferred increased, from approximately 24% among cycles that involved the transfer of one embryo to 15% among cycles that involved the transfer of four or more embryos. Transferring more embryos increases the chance for a multiple-fetus pregnancy. Multiple-fetus pregnancies are associated with increased risk of adverse outcomes for mothers and infants, including higher rates of prematurity, low birth weight, and pregnancy complications. See Figure 28 for more details about percentages of transfers that resulted in live births and multiple births, by number of embryos transferred, among younger patients with a prognosis for a good perinatal outcome.

Figure 26: Percentages of Transfers That Resulted in a Good Perinatal Outcome Using Fresh Nondonor Eggs or Embryos, by Number of Embryos Transferred, 2011.

Download Slide 26 [PDF - 238KB]

Is an ART cycle more likely to be successful if more embryos are transferred?

Figure 27 shows the relationship between the number of fresh nondonor eggs or embryos transferred, the percentage of transfers resulting in live births, and the percentage of multiple-infant live births for these cycles. In 2011, the percentage of transfers that resulted in live births increased when two or three embryos were transferred; however, transferring multiple embryos also poses a risk of having a multiple-infant birth. Multiple-infant births cause concern because of the additional health risks they create for both mothers and infants.

Interpretation of the relationship between the number of embryos transferred, the percentage of transfers resulting in live births, and the percentage of multiple-infant births is complicated by several factors, such as the woman’s age and embryo quality. See Figures 28 and 32 for more details on women using fresh nondonor eggs or embryos who are most at risk of multiple births.

Figure 27: Percentages of Transfers That Resulted in Live Births and Percentages of Multiple-Infant Live Births for ART Cycles Using Fresh Nondonor Eggs or Embryos, by Number of Embryos Transferred, 2011.

Download Slide 27 [PDF - 257KB]

Are percentages of transfers that result in live births affected by the number of embryos transferred for women who have more embryos available than they choose to transfer?

Figure 28 shows the relationship between the number of fresh nondonor eggs or embryos transferred, the percentage of transfers resulting in live births, and the percentage of multiple-infant births for ART procedures in which the woman was younger than age 35 and chose to set aside extra embryos for future cycles rather than transfer all available embryos at one time.

In 2011, the percentage of transfers that resulted in live births was the highest (56%) when two embryos were transferred; however, the highest percentage of singleton live births was observed with the transfer of one embryo.

Figure 28: Percentages of Transfers That Resulted in Live Births and Percentages of Multiple-Infant Live Births for ART Cycles Among Women Who Were Younger Than Age 35, Used Fresh Nondonor Eggs or Embryos, and Set Aside Extra Embryos for Future Use, by Number of Embryos Transferred, 2011.

Download Slide 28 [PDF - 256KB]

How long after egg retrieval does embryo transfer occur?

Once an ART cycle has progressed from egg retrieval to fertilization, the embryo(s) can be transferred into the woman’s uterus in the subsequent 1 to 6 days. Figure 29 shows that in 2011 approximately 50% of embryo transfers occurred on day 3. Day 5 embryo transfers were the next most common, accounting for about 40% of ART procedures that progressed to the embryo transfer stage.

Figure 29: Day of Embryo Transfer Among ART Cycles Using Fresh Nondonor Eggs or Embryos, 2011.

Download Slide 29 [PDF - 238KB]

Is an ART cycle more likely to be successful if embryos are transferred on day 5?

As shown in Figure 29, in the vast majority of ART procedures using fresh nondonor embryos, embryos were transferred on day 3 (50%) or day 5 (40%). Figure 30 compares percentages of day 3 embryo transfers that resulted in live births with those for day 5 embryo transfers. In all age groups, percentages were higher for day 5 embryo transfers than for day 3 transfers. However, some cycles do not progress to the embryo transfer stage because of embryo arrest (interruption in embryo development) between day 3 and day 5. These cycles are not accounted for in percentages of day 5 transfers that resulted in live births. Therefore, differences in percentages of day 3 and day 5 transfers that result in live births should be interpreted with caution.

Figure 30: Percentages of Day 3 and Day 5 Embryo Transfers Using Fresh Nondonor Eggs or Embryos That Resulted in Live Births, by Age Group, 2011.

Figure 30: Percentages of Day 3 and Day 5 Embryo Transfers Using Fresh Nondonor Eggs or Embryos That Resulted in Live Births, by Age Group, 2011.

Download Slide 30 [PDF - 239KB]

Does the number of embryos transferred differ for day 3 and day 5 embryo transfers?

Figure 31 shows the number of fresh nondonor embryos transferred on day 3 and day 5. Overall, fewer embryos were transferred on day 5 than on day 3. Approximately 42% of day 3 embryo transfers and 14% of day 5 embryo transfers involved the transfer of three or more embryos. The decrease in the number of embryos transferred on day 5, however, did not translate into a lower risk multiple-infant births. See Figure 32 for more details on the relationship between multiple-infant birth risk and day of embryo transfer.

Figure 31: Numbers of Embryos Transferred Among ART Cycles Using Fresh Nondonor Eggs or Embryos for Day 3 and Day 5 Embryo Transfers, 2011.

Download Slide 31 [PDF - 239KB]

How does the multiple-infant birth risk vary by the day of embryo transfer among fresh nondonor cycles?

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 32 shows that among the 11,989 live births that occurred following the transfer of day 3 fresh nondonor embryos, about 75% were singletons, 24% were twins, and 1% were triplets or more. Thus, approximately 25% of these live births produced more than one infant.

In 2011, a total of 15,208 live births occurred following the transfer of day 5 fresh nondonor embryos. Part B of Figure 32 shows that approximately 32% of these live births produced more than one infant.

As shown in Figure 31, fewer embryos were transferred on day 5 than on day 3. However, the proportion of live births resulting in twins is higher among transfer procedures performed on day 5 than on day 3. Thus, the risk of having a multiple-infant birth was higher for day 5 embryo transfers.

Figure 32: Distribution of Multiple-Infant Live Births Among ART Cycles Using Fresh Nondonor Eggs or Embryos for Day 3 and Day 5 Embryo Transfers, 2011.

Download Slide 32 [PDF - 239KB]

For day 5 embryo transfers, are percentages of transfers that result in live births affected by the number of embryos transferred for women who have more embryos available than they choose to transfer?

As shown in Figure 32, the transfer of fresh nondonor embryos on day 5 resulted in a higher percentage of multiple-infant births compared with embryos transferred on day 3. Figure 33 shows the relationship between the number of embryos transferred, the percentage of transfers resulting in live births, and the percentage of multiple-infant births for day 5 transfers among women who were younger than age 35 and set aside extra embryos for future cycles rather than transfer all available embryos at one time.

In 2011, the percentage of transfers resulting in live births was the highest (about 59%) when two embryos were transferred; however, the proportion of live births that were multiples (twins or more) — which present a higher risk of poor health outcomes — was about 46%. The percentage of live births that were higher-order multiples (triplets or more) was much higher when three or more embryos were transferred on day 5 (approximately 8%) than when two embryos were transferred on day 5 (approximately 1%).

If one measures success as the percentage of transfers resulting in singleton live births, the highest percentage (51%) resulted from the transfer of a single embryo on day 5.

Figure 33: Percentages of Transfers That Resulted in Live Births and Percentages of Multiple-Infant Live Births for Day 5 Embryo Transfers Among Women Who Were Younger Than Age 35, Used Fresh Nondonor Eggs or Embryos, and Set Aside Extra Embryos for Future Use, by Number of Embryos Transferred, 2011.

Download Slide 33 [PDF - 242KB]

How do percentages of transfers that result in live births for ART cycles using gestational carriers compare with those that do not use gestational carriers?

A gestational carrier is a woman who agrees to carry the developing embryo for others. Gestational carriers were used in about 1% of ART cycles using fresh nondonor embryos in 2011 (907 cycles). Figure 34 compares percentages of transfers that resulted in live births for ART cycles that used a gestational carrier in 2011 with cycles that did not. In most age groups, percentages of transfers that resulted in live births for ART cycles that used gestational carriers were higher than for those cycles that did not.

Figure 34: Comparison of Percentages of Transfers Using Fresh Nondonor Eggs or Embryos That Resulted in Live Births Between ART Cycles That Used Gestational Carriers and Those That Did Not, by Age Group, 2011.

Download Slide 34 [PDF - 242KB]

 

ART 2011 National Summary Presentation.
[PDF - 860KB]

Contact Us:
  • Centers for Disease Control and Prevention
    1600 Clifton Rd
    Atlanta, GA 30333
  • 800-CDC-INFO
    (800-232-4636)
    TTY: (888) 232-6348
  • Contact CDC-INFO
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO
A-Z Index
  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #