Meetings with assisted reproductive technology (ART) clinics for validation of ART data were conducted during June through August 2021. For data validation, 33 of the 448 reporting clinics were randomly selected after taking into consideration the number of ART cycles performed at each clinic, some cycle and clinic characteristics, and whether the clinic had been selected before. During each validation meeting, ART data reported by the clinic to CDC were compared with information documented in medical records.
For each clinic, the fully validated sample included up to 40 cycles resulting in pregnancy and up to 20 cycles not resulting in pregnancy. Up to 10 cycles using donor eggs or embryos were included among the fully validated sample at each clinic. In total, 1,945 ART cycles across the 33 clinics were randomly selected for full validation, along with 262 fertility preservation banking cycles selected for partial validation. In addition, among patients whose cycles were fully validated, the number of ART cycles performed during the year was verified. For each of these patients, the total number of cycles reported was compared with the total number of cycles in the medical record. If unreported ART cycles were identified in selected medical records, up to 10 of these cycles were also selected for partial validation.
Discrepancy rates are presented on the next pages for the validated items of interest. Overall, validation of 2019 ART cycle data indicated that most discrepancy rates were low (less than 5%).
Data Field Name
|Patient date of birth||
|Cycle start date||
|Date of egg retrieval||
|Number of eggs or embryos transferred||
|Outcome of ART treatment (i.e., pregnant, or not pregnant)||
|For about 50% of discrepancies, clinical intrauterine gestation was misreported when there was no information in the medical record to confirm it. For 23% of discrepancies, absence of pregnancy was misreported when confirmation of clinical intrauterine gestation was found in the medical record.|
|Pregnancy outcome (for example, miscarriage, live-birth delivery, or stillbirth)||
|For 50% of discrepancies, pregnancy outcome was misreported as live birth when there was no information on pregnancy outcome in the medical record to confirm the birth.|
|Date of pregnancy outcome||
|For 54% of discrepancies, pregnancy outcome date was not found in the medical record. When the medical record included the date of pregnancy outcome, 32% of discrepancies were within 7 days of the reported date.|
|Number of infants born||
|Patient Diagnosis—Reason for ART|
|For about 50% of discrepancies, tubal factor was found in medical records but was not reported by the clinic. For the 50% of discrepancies, tubal factor diagnosis was reported, but was not confirmed by the medical record.|
|Ovulatory dysfunction was underreported. For 83% of discrepancies, ovulatory dysfunction was found in medical records, but was not reported by the clinic.|
|Diminished ovarian reserve||
|Diminished ovarian reserve was underreported. For 78% of discrepancies, diminished ovarian reserve was found in medical records, but was not reported by the clinic.|
|Uterine factor was slightly underreported. For 63% of discrepancies, uterine factor was found in medical records, but was not reported by the clinic.|
|Male factor was underreported. For 74% of discrepancies, male factor was found in medical records, but was not reported by the clinic.|
|Other factor was underreported. For 76% of discrepancies, other factor was found in medical records, but was not reported by the clinic.|
|Unknown factor was overreported. For 90% of discrepancies, unknown factor diagnosis was not confirmed in medical records.|
* Discrepancy rates estimate the proportion of all assisted reproductive technology (ART) cycles with differences for a particular data item. The discrepancy rate calculations weight the data from validated cycles to reflect the overall number of cycles performed at each clinic. Thus, findings from larger clinical practices were weighted more heavily than those from smaller practices.
† This table shows a range, called the 95% confidence interval, that conveys the reliability of the discrepancy rate. For a general explanation of confidence intervals, see the next section.
What is a confidence interval?
Simply speaking, confidence intervals are a useful way to consider margin of error, a statistic often used in voter polls to indicate the range within which a value is likely to be correct (for example, 30% of the voters favor a particular candidate with a margin of error of plus or minus 3.5%).
Why do we need to consider confidence intervals if we already know the exact discrepancy rates for each clinic?
No discrepancy rate or statistic is absolute. Suppose that during validation, a sample of 100 cycles was reviewed, and a discrepancy rate of 15% was determined for a particular data item with a 95% confidence interval of 10%–20%. The 15% discrepancy rate tells us that we estimate the average chance that a discrepancy occurred for the selected data field among all reported cycles to be 15% based on the results of our sample of 100 cycles. However, that estimated discrepancy rate may not match the true discrepancy rate that we would calculate if we were to validate every single cycle during a reporting year. The 95% confidence interval tells us that we are 95% confident that the true discrepancy rate is between 10% and 20%. In other words, if we were to repeat the process of selecting a sample of 100 cycles many times, calculating the discrepancy rate and 95% confidence interval for each sample, we would expect 95% of the calculated confidence intervals to capture the true discrepancy rate.
American Society for Reproductive Medicine (ASRM). Professional society whose affiliate organization, the Society for Assisted Reproductive Technology (SART), is composed of clinics and programs that provide ART.
ART (assisted reproductive technology). All treatments or procedures that include the handling of human eggs or embryos to help a woman become pregnant. ART includes but is not limited to in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), zygote intrafallopian transfer (ZIFT), tubal embryo transfer, egg and embryo cryopreservation, egg and embryo donation, and gestational surrogacy.
ART cycle. An ART cycle starts when a woman begins taking fertility drugs or having her ovaries monitored for follicle production. If eggs are produced, the cycle progresses to egg retrieval. Retrieved eggs are combined with sperm to create embryos. If fertilization is successful, at least one embryo is selected for transfer. If implantation occurs, the cycle may progress to clinical pregnancy and possibly live-birth delivery. ART cycles include any process in which (1) an ART procedure is performed, (2) a woman has undergone ovarian stimulation or monitoring with the intent of having an ART procedure, or (3) frozen embryos have been thawed with the intent of transferring them to a woman.
Canceled cycle. An ART cycle in which ovarian stimulation was performed but the cycle was stopped before eggs were retrieved or before embryos were transferred. Cycles are canceled for many reasons: eggs may not develop, the patient may become ill, or the patient may choose to stop treatment.
Cryopreservation. The practice of freezing eggs or embryos from a patient’s ART cycle for potential future use.
Diminished ovarian reserve. This diagnosis means that the ability of the ovary to produce eggs is reduced. Reasons include congenital, medical, or surgical causes.
Donor egg cycle. An ART cycle in which an embryo is formed from the egg of one woman (the donor) and then transferred to another woman (the recipient). Sperm from either the recipient’s partner or a donor may be used.
Donor embryo cycle. An ART cycle in which an embryo that is donated by a patient or couple who previously underwent ART treatment and had extra embryos available is transferred to another woman (the recipient).
Ectopic pregnancy. A pregnancy in which the fertilized egg implants in a location outside of the uterus—usually in the fallopian tube, the ovary, or the abdominal cavity. Ectopic pregnancy is a dangerous condition that must receive prompt medical treatment.
Egg. A female reproductive cell, also called an oocyte or ovum.
Egg/Embryo banking cycle. An ART cycle started with the intention of freezing (cryopreserving) all resulting eggs or embryos for potential future use.
Egg retrieval (also called oocyte retrieval). A procedure to collect the eggs contained in the ovarian follicles.
Egg transfer (also called oocyte transfer). The transfer of retrieved eggs into a woman’s fallopian tubes through laparoscopy. This procedure is used only in GIFT.
Embryo. An egg that has been fertilized by a sperm and has then undergone one or more cell divisions.
Embryo transfer. Placement of embryos into a woman’s uterus through the cervix after IVF. In zygote intrafallopian transfer, zygotes are placed in a woman’s fallopian tube.
Endometriosis. A medical condition that involves the presence of tissue similar to the uterine lining in locations outside the uterus such as the ovaries, fallopian tubes, or abdominal cavity.
Fertility Clinic Success Rate and Certification Act of 1992 (FCSRCA). Law passed by the United States Congress in 1992 requiring all clinics performing ART in the United States to annually report their success rate data to the Centers for Disease Control and Prevention.
Fertility preservation cycle. An ART cycle started with the intent of freezing and banking all eggs or embryos for at least 12 months for future use.
Fertilization. The penetration of the egg by the sperm and the resulting combining of genetic material that develops into an embryo.
Fetus. The unborn offspring from the eighth week after conception to the moment of birth.
Follicle. A structure in the ovaries that contains a developing egg.
Fresh eggs, sperm, or embryos. Eggs, sperm, or embryos that have not been frozen.
Fresh embryo cycle. An ART cycle in which fresh (never frozen) embryos are transferred to the woman. The fresh embryos are conceived with fresh or frozen eggs and fresh or frozen sperm.
Frozen egg cycle. An ART cycle in which frozen (cryopreserved) eggs are thawed, fertilized, and then the resulting fresh embryo is transferred to the woman. Frozen and thawed eggs may be fertilized with either fresh or frozen sperm.
Frozen embryo cycle. An ART cycle in which frozen (cryopreserved) embryos are thawed and transferred to the woman. Frozen embryos may have been conceived using fresh or frozen eggs and fresh or frozen sperm.
Gamete. A reproductive cell, either a sperm or an egg.
Gestational age. The deviation of time from estimated last menstrual period (LMP) to birth. LMP is estimated using the date of retrieval or transfer.
Gestational carrier (also called a gestational surrogate). A woman who gestates, or carries, an embryo that was formed from the egg of another woman with the expectation of returning the infant to its intended parents.
Gestational sac. A fluid-filled structure that develops within the uterus early in pregnancy. In a normal pregnancy, a gestational sac contains a developing fetus.
GIFT (gamete intrafallopian transfer). An ART procedure that involves removing eggs from the woman’s ovary and using a laparoscope to place the unfertilized eggs and sperm into the woman’s fallopian tube through small incisions in her abdomen.
ICSI (intracytoplasmic sperm injection). A procedure in which a single sperm is injected directly into an egg; this procedure is commonly used to overcome male infertility problems.
Implantation rate. A measurement of ART success when the ART cycle results in an intrauterine
clinical pregnancy, defined as the larger of either the number of maximum fetal hearts by ultrasound or maximum infants born, including live-birth deliveries and stillbirths, out of the total number of embryos transferred.
Infertility. In general, infertility refers to the inability to conceive after 12 months of unprotected intercourse. Women aged 35 or older unable to conceive after 6 months of unprotected intercourse generally are considered infertile for the purpose of initiating medical treatment.
IUI (intrauterine insemination). A medical procedure that involves placing sperm into a woman’s uterus to facilitate fertilization. IUI is not considered an ART procedure because it does not involve the manipulation of eggs.
IVF (in vitro fertilization). An ART procedure that involves removing eggs from a woman’s ovaries and fertilizing them outside her body. The resulting embryos are then transferred into a woman’s uterus through the cervix.
Live-birth delivery. The delivery of one or more infants with at least one alive.
Male factor infertility. Any cause of infertility due to low sperm count or problems with sperm function that makes it difficult for a sperm to fertilize an egg under normal conditions.
Miscarriage (also called spontaneous abortion). A pregnancy ending in the spontaneous loss of the embryo or fetus before 20 weeks of gestation.
Multiple-fetus pregnancy. A pregnancy with two or more fetuses, determined by the number of fetal hearts observed on an ultrasound.
Multiple live-birth delivery. The delivery of more than one infant with at least one born live.
NASS (National ART Surveillance System). Web-based data collection system used by all ART clinics to report data for each ART procedure to CDC.
Oocyte. The female reproductive cell, also called an egg.
Other reason, infertility. Reason for using ART including immunological problems, chromosomal abnormalities, cancer chemotherapy, and serious illnesses.
Other reason, non-infertility. Reason for using ART not related to infertility and not unexplained or unknown.
Ovarian hyperstimulation syndrome. A possible complication of ovarian stimulation or ovulation induction that can cause enlarged ovaries, a distended abdomen, nausea, vomiting or diarrhea, fluid in the abdominal cavity or chest, breathing difficulties, changes in blood volume or viscosity, and diminished kidney perfusion and function.
Ovarian monitoring. The use of ultrasound, or blood or urine tests to monitor follicle development and hormone production.
Ovarian stimulation. The use of drugs (oral or injected) to stimulate the ovaries to develop follicles and eggs.
Ovulatory dysfunction. A diagnostic category used when a woman’s ovaries are not producing eggs normally. It is usually characterized by irregular menstrual cycles reflective of ovaries that are not producing one mature egg each month. It includes polycystic ovary syndrome and multiple ovarian cysts.
Patient (nondonor) cycle. An ART cycle in which an embryo is formed from the egg of the patient and either partner or donor sperm and then transferred back to the patient.
PGT (preimplantation genetic testing). Diagnostic or screening techniques performed on embryos prior to transfer for detecting specific genetic conditions to reduce the risk of passing inherited diseases to children or screening for an abnormal number of chromosomes, which is of special value for patients with advanced age, recurrent miscarriages, or prior failed IVF.
Pregnancy (clinical). A pregnancy documented by ultrasound that shows a gestational sac in the uterus. For ART data reporting purposes, pregnancy is defined as a clinical pregnancy rather than a chemical pregnancy (positive pregnancy test).
SET (single embryo transfer). Single embryo transfer is a procedure in which one embryo, regardless of how many embryos are available, is placed in the uterus or fallopian tube. The embryo selected for SET might be a frozen (cryopreserved) embryo from a previous IVF cycle or a fresh embryo yielded during the current fresh IVF cycle.
Singleton live-birth delivery. The delivery of a single infant born alive.
Society for Assisted Reproductive Technology (SART). An affiliate of ASRM composed of clinics and programs that provide ART.
Sperm. The male reproductive cell.
Spontaneous abortion. See Miscarriage.
Stillbirth. The birth of an infant that shows no sign of life after 20 or more weeks of gestation.
Stimulated cycle. An ART cycle in which a woman receives oral or injected fertility drugs to stimulate her ovaries to develop follicles that contain mature eggs.
Thawed embryo cycle. Same as frozen embryo cycle.
Tubal factor infertility. A diagnostic category used when the woman’s fallopian tubes are blocked
or damaged, making it difficult for the egg to be fertilized or for an embryo to travel to the uterus.
Ultrasound. A technique used in ART for visualizing the follicles in the ovaries, the gestational sac, or the fetus.
Unexplained infertility. A diagnostic category used when no cause of infertility is found in either the woman or the man.
Unstimulated cycle. An ART cycle in which the woman does not receive drugs to stimulate her ovaries to produce more follicles and eggs. Instead, follicles and eggs develop naturally.
Uterine factor infertility. A structural or functional disorder of the uterus that results in reduced fertility.
ZIFT (zygote intrafallopian transfer). An ART procedure in which eggs are collected from a woman’s ovary and fertilized outside her body. A laparoscope is then used to place the resulting zygote into the woman’s fallopian tube through a small incision in her abdomen.
Zygote. A fertilized egg before it begins to divide.
NOTE that CDC does not oversee any of these accreditation programs. Effective in 2021, the New York State Tissue Bank Program will no longer be providing accreditation for embryo laboratories.
Persons with disabilities experiencing problems accessing the ART National Summary Report file should contact ARTinfo@cdc.gov, or call 1-800-CDC-INFO (1-800-232-4636).
The below are accessible explanations for figures for the 2019 National ART Summary section of the report.
Persons with disabilities experiencing problems accessing the ART National Summary Report file should contact ARTinfo@cdc.gov, or call 1-800-CDC-INFO (1-800-232-4636).
Figure 1. This pie chart shows the distribution of ART use in 2019 by 5 patient age groups. Percentages for each age group were as follows: 36.7% were younger than age 35, 23.0% were aged 35 to 37, 19.9% were aged 38 to 40, 9.5% were aged 41 to 42, and 10.9% were older than age 42.
Figure 2. This pie chart shows the outcomes of clinical pregnancies from ART cycles performed in 2019. Of these pregnancies, 75.9% resulted in the birth of a single infant, 6.1% resulted in the birth of multiple infants, 15.8% resulted in miscarriage, 0.5% resulted in stillbirth, and 1.6% was reported as other or unknown.
Figure 3. This horizontal line graph shows the percentage of embryo transfers that resulted in live-birth delivery in 2019 by patient age and egg or embryo source. The vertical Y-axis presents percentages from 0% to 60% in increments of 10. The horizontal X-axis presents patient age, from younger than age 30 to older than age 45. The first line shows that the percentage of embryo transfers that used donor eggs or embryos decreased with patient age, from 49.3% to 39.2%. The second line shows that the percentage of embryo transfers that used patient eggs or embryos decreased with age, from 43.2% to 9.7%.
Figure 4. This horizontal bar graph shows the reported reasons for using ART in 2019. The vertical Y-axis presents 13 reasons for using ART. The horizontal X-axis presents percentages from 0% to 40% in increments of 5. Percentages for each reason were as follows: 36.8% egg or embryo banking, 28.6% diminished ovarian reserve, 27.5% male factor infertility, 26.8% other reasons related to infertility, 15.1% preimplantation genetic testing, 13.9% ovulatory dysfunction, 10.8% unexplained factor, 10.5% tubal factor, 6.6% endometriosis, 6.3% uterine factor, 5.5% recurrent pregnancy loss, 4.8% other reasons not related to infertility, and 1.9% gestational carrier.
Figure 5. This vertical bar graph shows the percentage of infants conceived using ART procedures started in 2019 who were born preterm or with low birth weight. The vertical Y-axis presents percentages from 0% to 100% in increments of 10. The horizontal X-axis presents the type of live-birth delivery. Among single infants born from single-fetus pregnancies, 11.8% were preterm and 11.8% were low birth weight. Among single infants born from multiple-fetus pregnancies, 23.7% were preterm and 24.5% were low birth weight. Among twin infants, 59.8% were preterm and 56.5% were low birth weight. Among triplet or more infants, 95.0% were preterm and 97.2% were low birth weight.
Figure 6. This horizontal line graph shows the number of ART cycles, embryo transfers, and banking cycles performed and the number of live-birth deliveries that resulted from 2010 through 2019. The vertical Y-axis presents numbers from 0 to 350,000 in increments of 50,000. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The number of ART cycles started increased from 154,427 in 2010 to 330,773 in 2019. Embryo transfers increased from 125,399 in 2010 to 171,206 in 2019. Banking cycles increased from 7,163 in 2010 to 121,086 in 2019. Live-birth deliveries increased from 47,104 in 2010 to 77,998 in 2019.
Figure 7. This horizontal line graph shows the number of ART cycles performed from 2010 through 2019 by egg or embryo source. The vertical Y-axis presents numbers from 0 to 140,000 in increments of 20,000. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The number of cycles performed using embryos from fresh patient eggs decreased from 100,824 in 2010 to 56,369 in 2019. Cycles performed using embryos from frozen patient eggs or embryos increased from 28,425 in 2010 to 126,187 in 2019. Cycles performed using embryos from fresh donor eggs decreased from 10,849 in 2010 to 2,138 in 2019. Cycles performed using embryos from frozen donor eggs or embryos increased from 7,162 in 2010 to 24,993 in 2019.
Figure 8. This combined vertical bar graph and horizontal line graph shows the number and percentage of embryo transfers that used a gestational carrier from 2010 through 2019. The left vertical Y-axis presents numbers from 0 to 10,000 in increments of 1,000. The right vertical Y-axis presents percentages from 0% to 6.0% in increments of 0.5%. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The number of cycles that used a gestational carrier increased from 2,649 in 2010 to 9,195 in 2019. The percentage of cycles that used a gestational carrier also increased, from 2.1% in 2010 to 5.4% in 2019.
Figure 9. This horizontal line graph shows the percentage of embryo transfers in which a single embryo was transferred from 2010 through 2019. The vertical Y-axis presents percentages from 0% to 90% in increments of 10. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The percentage of embryo transfers that used a single embryo increased from 18.2% in 2010 to 77.3% in 2019.
Figure 10. This horizontal line graph shows the percentage of ART cycles that resulted in live-birth deliveries from 2010 through 2019 by patient age group. The vertical Y-axis presents percentages from 10% to 50% in increments of 5. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The percentage of ART cycles that resulted in live-birth deliveries increased from 32.0% in 2010 to 37.2% in 2019 for all age groups combined. The percentage increased from 40.3% in 2010 to 42.4% in 2019 for patients younger than age 35, from 32.7% in 2010 to 38.9% in 2019 for patients aged 35 to 37, from 25.2% in 2010 to 33.7% in 2019 for patients aged 38 to 40, and from 22.3% in 2010 to 28.5% in 2019 for patients older than age 40.
Figure 11. This vertical bar graph shows the number of infants born from 2010 through 2019 who were conceived using ART. The vertical Y-axis presents numbers from 0 to 90,000 in increments of 10,000. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The number of infants born was 61,556 in 2010, 61,599 in 2011, 65,151 in 2012, 67,996 in 2013, 68,782 in 2014, 71,152 in 2015, 76,914 in 2016, 78,052 in 2017, 81,478 in 2018, and 83,946 in 2019.
Figure 12. This horizontal line graph shows the percentage of embryo transfers that resulted in the live-birth delivery of singletons, twins, or triplets or more from 2010 through 2019. The vertical Y-axis presents percentages from 0% to 40% in increments of 5. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The first line shows that the percentage of embryo transfers that resulted in singletons increased from 22.6% in 2010 to 34.4% in 2019. The second line shows that the percentage of embryo transfers that resulted in twins decreased from 9.0% in 2010 to 2.7% in 2019. The third line shows that the percentage of embryo transfers that resulted in triplets or more decreased from 0.4% in 2010 to 0.06% in 2019.
Figure 13. This vertical stacked bar graph shows the percentage of infants conceived using ART cycles that resulted in the live-birth delivery of singletons, twins, or triplets or more from 2010 through 2019. The vertical Y-axis presents 0% to 100% in increments of 20. The horizontal X-axis presents the data reporting year, from 2010 through 2019. The first stack shows that the percentage of infants who were part of a singleton live-birth delivery increased from 70.6% in 2010 to 92.5% in 2019. The second stack shows that the percentage of infants who were part of a twin live-birth delivery decreased from 28.1% in 2010 to 7.3% in 2019. The third stack shows that the percentage of infants who were part of a triplet or more live-birth delivery decreased from 1.3% in 2010 to 0.2% in 2019.