Section 2: ART Cycles Using Fresh, Nondonor Eggs or Embryos (Part B)
Section 2 it is broken up into three parts. Part B contains Figures 16–25.
A woman’s age not only affects the chance for pregnancy when her own eggs are used, but also affects her risk of miscarriage. Figure 16 shows percentages of ART cycles using fresh nondonor eggs or embryos in 2011 that resulted in miscarriage for women of different ages. Percentages of ART cycles that resulted in miscarriage were below 15% among women aged 35 or younger. The percentage of ART cycles that resulted in miscarriages began to increase rapidly among women in their mid- to late 30s and continued to increase with age, reaching more than 25% at age 40 and over 70% among women older than age 44.
Previous data show that most miscarriages occur before week 14 (i.e., during the first trimester) among women of all ages undergoing ART. The risk of miscarriage among women undergoing ART procedures using fresh nondonor eggs or embryos appears to be similar to those reported in various studies of other pregnant women in the United States.
In 2011, a total of 101,213 cycles using fresh nondonor eggs or embryos were started:
- 42,059 among women younger than age 35
- 20,963 among women aged 35–37 years
- 21,128 among women aged 38–40 years
- 10,733 among women aged 41–42 years
- 4,744 among women aged 43–44 years
- 1,586 among women older than age 44
Figure 17 shows that a woman’s chance of progressing from the beginning of ART to pregnancy and live birth (using her own eggs) decreases at every stage of ART as her age increases.
As women get older:
- The likelihood of a successful response to ovarian stimulation and progression to egg retrieval decreases.
- Cycles that have progressed to egg retrieval are less likely to reach transfer.
- The percentage of cycles that progress from transfer to pregnancy also decreases.
- Cycles that have progressed to pregnancy are less likely to result in a live birth because the risk of miscarriage is greater (see Figure 16).
Overall, 40% of cycles started in 2011 among women younger than age 35 resulted in live births. This percentage decreased to 32% among women aged 35–37, 22% among women aged 38–40, 12% among women aged 41–42, 5% among women aged 43–44, and 1% among women older than age 44.
Figure 18 shows infertility diagnoses reported among patients who had ART using fresh nondonor eggs or embryos in 2011. Diagnoses range from one infertility factor in the patient or partner to multiple infertility factors in either one or both. However, diagnostic procedures may vary among clinics, so the categorizations also may vary.
- Tubal factor—fallopian tubes are blocked or damaged, making it difficult for the egg to be fertilized or for an embryo to travel to the uterus.
- Ovulatory dysfunction—ovaries are not producing eggs normally. Reasons include polycystic ovary syndrome and multiple ovarian cysts.
- Diminished ovarian reserve—the ability of the ovary to produce eggs is reduced. Reasons include congenital, medical, or surgical causes or advanced age.
- Endometriosis—the presence of tissue similar to the uterine lining in abnormal locations. This condition can affect both fertilization of the egg and embryo implantation.
- Uterine factor—a structural or functional disorder of the uterus that results in reduced fertility.
- Male factor—a low sperm count or problems with sperm function that make it difficult for a sperm to fertilize an egg under normal conditions.
- Other factor—includes immunological problems, chromosomal abnormalities, cancer chemotherapy, and serious illnesses.
- Unknown factor—no cause of infertility is found in either the woman or the man.
- Multiple factors, female only—more than one female cause of infertility.
- Multiple factors, female and male—one or more female causes and male factor infertility.
Figure 19 shows the percentage of ART cycles using fresh nondonor eggs or embryos that resulted in live births according to the causes of infertility. (See Figure 18, or Appendix B: Glossary of Terms for an explanation of the diagnoses.) Although the national average was 29% in 2011 (see Figure 8), the percentage of ART cycles that resulted in live births varied somewhat depending on the patient’s diagnosis. In 2011, the percentage of ART cycles resulting in live births was higher than the national average for patients with ovulatory dysfunction, endometriosis, male factor, or unknown factor infertility; it was lower for patients with tubal factor, diminished ovarian reserve, uterine factor, “other” factor, or multiple infertility factors. Please note, however, that the definitions of infertility diagnoses may vary among clinics and that a review of select clinical records revealed that reporting of infertility causes may be incomplete. (See Appendix A: Validation for additional information.) Therefore, differences in success rates by causes of infertility should be interpreted with caution.
Do women who have previously given birth have higher percentages of ART cycles that result in live births?
Most ART procedures performed in 2011 using fresh nondonor eggs or embryos (70%) were among women who had no previous live births, although they may have had a pregnancy that resulted in a miscarriage or an induced abortion. Figure 20 shows the relationship between the success of ART cycles performed in 2011 using fresh nondonor eggs or embryos and a history of previous births. Previous live-born infants may have been conceived naturally or through ART. Overall, percentages of ART cycles that resulted in live births decreased with age regardless of number of previous live births. For women of all age groups except younger than age 35 and older than age 44, percentages of ART cycles that resulted in live births were slightly higher or equal among women who had one or more previous live births compared with those who had no previous live births.
Is there a difference in percentages of ART cycles that result in live births between women with previous miscarriages and women who have never been pregnant?
In 2011, a total of 71,244 ART cycles using fresh nondonor eggs or embryos were performed among women who had not previously given birth. However, about 27% of those cycles were reported by women with one or more previous pregnancies that had ended in miscarriage—CDC does not have information on whether the pregnancies ending in miscarriage were the result of ART or were conceived naturally. Figure 21 shows the relationship between the success of an ART cycle in 2011 and the history of previous miscarriage. In all age groups, percentages of cycles that resulted in live births were similar among women who had one or more previous miscarriages and women who never were pregnant. Thus, a history of unsuccessful pregnancy does not appear to be associated with lower chances for success using ART.
Do percentages of ART cycles that result in live births differ for women who use ART for the first time compared with women who previously used ART but did not give birth?
Figure 22 shows the relationship between the success of ART cycles performed in 2011 using fresh nondonor eggs or embryos and a history of previous ART cycles among women with no previous births. For about 43% of ART procedures performed in 2011, one or more previous ART cycles were reported (this percentage includes previous cycles using either fresh or frozen embryos). In the majority of age groups, percentages of ART cycles that resulted in live births among women who previously had one or more unsuccessful ART cycle were lower or similar to those among women who had no previous ART cycles and no previous births.
Do percentages of retrievals that result in live births differ among patients who do or do not use ICSI with or without diagnosed male factor infertility?
ICSI was developed to overcome problems with fertilization that sometimes occur with a diagnosis of male factor infertility. In 2011, a total of 85% of cycles with a diagnosis of male factor infertility used IVF with ICSI, but slightly more than half (54%) of all ICSI procedures were performed without a diagnosis of male factor infertility. Figure 23 presents percentages of retrievals that resulted in live births using ICSI with or without a diagnosis of male factor infertility compared with not using ICSI and no diagnosis of male factor infertility. For most age groups, when ICSI was used for patients with male factor infertility, percentages of retrievals that resulted in live births were similar to those without ICSI and no diagnosis of male factor infertility. For all cycles where ICSI was used, procedures were less successful if there was no diagnosis of male factor infertility. Please note, however, that the definitions of infertility diagnoses may vary among clinics, and no information was available to determine whether this finding was a direct effect of the ICSI procedure or whether the patients’ characteristics were different among those who used ICSI compared with those who used IVF without ICSI. Therefore, differences in success rates should be interpreted with caution.
Figure 24 shows that in 2011, the majority (71%) of ART cycles that used fresh nondonor eggs or embryos and progressed to the embryo transfer stage involved the transfer of one or two embryos. Approximately 30% of cycles involved the transfer of three or more, about 9% of cycles involved the transfer of four or more, and approximately 3% of cycles involved the transfer of five or more embryos.
How do percentages of embryos transferred that result in implantation for fresh nondonor embryos differ among women of different ages?
Figure 25 presents the relationship between the implantation percentage (see Implantation rate in Appendix B: Glossary of Terms) for fresh nondonor embryos transferred and a woman’s age. In 2011, the percentage of embryos transferred that resulted in implantation was highest (approximately 36%) among women younger than age 35. However, the implantation percentage decreased steadily as the age of the woman increased. Specifically, the implantation percentage was lowest (about 2%) among women older than age 44 compared with the implantation percentage among women in each of the other age groups.