Elective single-embryo transfer (eSET) is a procedure where a woman undergoing IVF chooses to have a single embryo transferred, selected from a larger number of available embryos. Learn how eSET reduces the risk of multiple births and related pregnancy complications.
Human fertilized egg cleaved into twelve divisions
Image by TheVisualMD
What Is eSET?
Cell Division
Image by "Conception to Birth: The Visual Guide to Your Pregnancy" by Alexander Tsiaras
Cell Division
The fertilized egg, termed a zygote, divides into 2 cells after about 24 hours, 4 cells after 48 hours, and 6-12 cells in 3 days. At about 5 days, the zygote has transformed into a hollow ball called the blastocyst.
Image by "Conception to Birth: The Visual Guide to Your Pregnancy" by Alexander Tsiaras
What Is Elective Single Embryo Transfer (ESET)?
Elective single-embryo transfer (eSET) is a procedure in which one embryo, selected from a larger number of available embryos, is placed in the uterus or fallopian tube. The embryo selected for eSET might be from a previous IVF cycle (e.g., cryopreserved embryos (frozen)) or from the current fresh IVF cycle that yielded more than one embryo. The remaining embryos may be set aside for future use or cryopreservation.
eSET helps women avoid several risks to their own health that are associated with carrying multiples. It also helps families achieve success while preventing some risks known to be associated with giving birth to twins or what is called “high order multiple births” (three or more children born at the same time). Infants born in multiple births are more often born early (preterm), are smaller (low birth weight) and experience more adverse health outcomes than singleton infants. There is consensus among experts that the desired outcome of ART is a healthy singleton infant.
Source: Centers for Disease Control and Prevention (CDC)
Additional Materials (8)
Infertility: Considering Elective Single Embryo Transfer
Video by Centers for Disease Control and Prevention (CDC)/YouTube
How Many Embryos Should You Transfer with IVF?
Video by Attain Fertility/YouTube
Single Embryo Transfer by choice at Michigan Reproductive Medicine
Video by Michigan Reproductive Medicine/YouTube
The Benefits of Single Embryo Transfer
Video by IRMS Institute for Reproductive Medicine and Science/YouTube
How To Tell If Elective Single Embryo Transfer Is Right For You
Video by Attain Fertility/YouTube
Why Single Embryo Transfer in IVF Is Not for Everyone
Video by Center for Human Reproduction/YouTube
Why is single embryo transfer encouraged?
Video by fertilityauthority/YouTube
Human fertilized egg cleaved into twelve divisions
Mitotic Division Resulting in twelve cells - Human fertilized egg cleaved into twelve divisions
Image by TheVisualMD
4:14
Infertility: Considering Elective Single Embryo Transfer
Centers for Disease Control and Prevention (CDC)/YouTube
3:16
How Many Embryos Should You Transfer with IVF?
Attain Fertility/YouTube
3:11
Single Embryo Transfer by choice at Michigan Reproductive Medicine
Michigan Reproductive Medicine/YouTube
3:47
The Benefits of Single Embryo Transfer
IRMS Institute for Reproductive Medicine and Science/YouTube
9:54
How To Tell If Elective Single Embryo Transfer Is Right For You
Attain Fertility/YouTube
1:34
Why Single Embryo Transfer in IVF Is Not for Everyone
Center for Human Reproduction/YouTube
2:24
Why is single embryo transfer encouraged?
fertilityauthority/YouTube
Human fertilized egg cleaved into twelve divisions
TheVisualMD
Is It Appropriate for Me?
Explosive Growth of the Embryo and early fetal Development
Image by TheVisualMD
Explosive Growth of the Embryo and early fetal Development
Explosive Growth In the space of just a few weeks, a microscopic fertilized egg transforms into a distinctly human fetus with a beating heart and articulated arms and legs, fingers and toes.
Image by TheVisualMD
Is ESET Appropriate for Me?
Research studies assesses the chances of success (pregnancy and live birth) based upon the number of embryos transferred during an ART procedure. This research found that among women with a good chance of success with ART, those who chose to have a single embryo transferred had a similar number of live-birth deliveries compared to those who chose to transfer multiple embryos, but almost all of the infants they delivered were singletons.
The guidelines on number of embryos transferred were developed by the Practice Committees of the American Society for Reproductive Medicine (ASRM) and the Society for Assisted Reproductive Technology (SART). According to these guidelines, single embryo transfer should be considered for patients with favorable prognosis, usually women aged 35 years or younger and with eggs or embryos of good quality. These guidelines have been developed to assist physicians with clinical decisions regarding the care of their patients. They are not intended to be a protocol to be applied in all situations, and cannot substitute for the individual judgment of the treating physicians based on their knowledge of their patients and specific circumstances.
Source: Centers for Disease Control and Prevention (CDC)
Additional Materials (4)
Human Embryonic and Fetal Development
Human Embryonic and Fetal Development : Three-dimensional visualization reconstructed from scanned human data of a 8 cell zygote, a 14-16 day old embryo, a 44 day old embryo, and a 9 week old fetus. The body does not increase greatly in size during the embryonic period. But during the the fetal period, beginning at week nine, a phase of rapid growth starts that continues until after birth.
Image by TheVisualMD
Early development stages - Animated GIF of cleavage, morula and gastrula stages
Early development stages - Animated GIF of cleavage, morula and gastrula stages
Image by Laird.sheldahl
Infertility: Considering Elective Single Embryo Transfer
Video by Centers for Disease Control and Prevention (CDC)/YouTube
Mitotic Division Resulting in Eight Blastomere
Photograph, actual size of zygote = 0.2 mm approx. - This image depicts the zygote, which has undergone three mitotic divisions. Eight cells, also called blastomeres, can be seen. They are all indicated in gray-green with a white-purple outline. By the third division, the blastomeres form a compact ball of cells. This process is called compaction, where inner and outer cells are separated. Communication between the inner and outer cells are done by way of gap junctions.
Image by TheVisualMD
Human Embryonic and Fetal Development
TheVisualMD
Early development stages - Animated GIF of cleavage, morula and gastrula stages
Laird.sheldahl
4:14
Infertility: Considering Elective Single Embryo Transfer
Centers for Disease Control and Prevention (CDC)/YouTube
Mitotic Division Resulting in Eight Blastomere
TheVisualMD
What If I Can't Get Pregnant with a Single Embryo?
Implantation (human embryo)
Image by OpenStax College
Implantation (human embryo)
Illustration of Implantation of a human embryo
Image by OpenStax College
What If I Have Waited and Tried Many Times to Get Pregnant Unsuccessfully?
The desire for childbearing and parenthood can be compelling. There are so many decisions to make as you determine whether ART is the right option for you and identify clinics that provide services. Remember, the best decisions are knowing your options and selecting one compatible with your beliefs and values about pregnancy, childbearing, and parenting.
Women experiencing infertility or wanting to have another child may find having multiples to be an “acceptable risk” when considering ART services. But as you see in our videos, circumstances and thoughts may change as you go through this journey. We also find that many who call CDC mention feeling pressured to make the “right” decision in a short period of time, perhaps without adequate time to talk through the outcomes of your decision with a partner. We urge you to consider the value of single embryo transfer as option BEFORE starting ART services.
Source: Centers for Disease Control and Prevention (CDC)
Additional Materials (1)
Mitotic Division Resulting in Sixteen Blastomere
Photograph, actual size of zygote = 0.2 mm approx. - This image depicts the zygote, which has undergone about four mitotic divisions. Sixteen cells, also called blastomeres, can be seen. They are all indicated in gray-green with a white-purple outline. At this point, the cluster of cells is called a morula and continues to divide. When the morula enters the uterus, changes occur to this sphere of cells to form a structure called the blastocyst.
Image by TheVisualMD
Mitotic Division Resulting in Sixteen Blastomere
TheVisualMD
Why Is a Multiple Birth Risky?
Twins
Image by Trlkly (Original by Wikipedia editor User:ChristinaT3)
Twins
Image Topic : Identical fraternal sperm egg : Comparison of typical zygote development in monozygotic identical and dizygotic twins.
Image by Trlkly (Original by Wikipedia editor User:ChristinaT3)
What Are the Risks Associated with Multiple Births?
Multiple births increase the risk of premature birth and low birth weight in infants. This can affect survival and well-being of newborns. These babies may require special care immediately after birth and at times, can face life-long problems such as developmental disabilities and delays.
Women who carry multiples may be more likely to need Caesarean sections which may require a longer period of recovery, and at times, can increase the risk of hemorrhage during and after delivery.
Some who become pregnant with multiples may find one or more cannot survive to term or even a premature birth. This may lead to a medical need to perform fetal reduction.
Women older than age 35 have an increased risk of pregnancy complications, some of which could be life threatening. Carrying multiples adds to this risk.
Source: Centers for Disease Control and Prevention (CDC)
Additional Materials (11)
How Many Children Can A Human Have In A Lifetime?
Video by Science Insider/YouTube
Embryos at 44 Days (8 for Gestational Age) with Circulatory System
Through rotation and gradual imaging techniques, these human fetal visualizations show the vast amount of blood circulation needed to fuel the extraordinary growth of a 44-day-old fetus. The images at the bottom show only the circulatory system. The blood transports so many substances and does so many jobs it's hard to name them. Chiefly, though, it moves oxygen and food to all parts of the body while taking away waste chemicals. This process necessarily begins in the first week, and by twenty days watertight tubes branch throughout the embryo. The system grows \"ahead\" of the baby, proliferating in all directions like highways on a busy map, stimulating new areas of development. (Understanding how blood vessels are laid down in relation to cellular reproduction has provided some of the most hopeful recent insights against cancer.) After birth this network also serves to provide the baby with central heat, distributing warmth evenly through the body, from busy parts like the heart to cooler areas like still muscles. Please see our Infant Nutrition Health Center.
Image by TheVisualMD
As Multiple Births Rise, Experts Call for Caution
Video by Wall Street Journal/YouTube
Multiple Births (Pregnancy Considerations #4)
Video by Healthguru/YouTube
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 1
Video by St. Louis Children's Hospital/YouTube
How will my twin or multiple births be managed? | NHS
Video by NHS/YouTube
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 4
Video by St. Louis Children's Hospital/YouTube
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 2
Video by St. Louis Children's Hospital/YouTube
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 3
Video by St. Louis Children's Hospital/YouTube
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 5
Video by St. Louis Children's Hospital/YouTube
Does IVF lead to twins and multiple births?
Video by Top Doctors UK/YouTube
3:22
How Many Children Can A Human Have In A Lifetime?
Science Insider/YouTube
Embryos at 44 Days (8 for Gestational Age) with Circulatory System
TheVisualMD
2:46
As Multiple Births Rise, Experts Call for Caution
Wall Street Journal/YouTube
2:54
Multiple Births (Pregnancy Considerations #4)
Healthguru/YouTube
9:35
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 1
St. Louis Children's Hospital/YouTube
1:52
How will my twin or multiple births be managed? | NHS
NHS/YouTube
8:03
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 4
St. Louis Children's Hospital/YouTube
9:00
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 2
St. Louis Children's Hospital/YouTube
9:39
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 3
St. Louis Children's Hospital/YouTube
2:52
Managing Many: The Risks, Realities and Rewards of Multiple Births - Part 5
St. Louis Children's Hospital/YouTube
1:21
Does IVF lead to twins and multiple births?
Top Doctors UK/YouTube
How Do I Decide If eSET Is for Me?
Morula
Image by ekem, Courtesy: RWJMS IVF Program
Morula
8-cell human embryo, day 3
Image by ekem, Courtesy: RWJMS IVF Program
How Do I Decide If ESET Is for Me?
Every person is different and every effort to begin or expand a family is different. Here are some suggestions that you might consider:
Take a few moments to review what are the “practical” and personal limits related to your choice. For example, women who wish to breastfeed may find it even more challenging when they are mothers of multiples. Others speak of the difficulty in finding affordable and reliable child care options outside or in the home. Even the logistics of transporting multiples can be daunting to some, especially for keeping well-child appointments, seeking emergency care, or taking care of routine housekeeping duties.
Identify the network of support you need now and will need during and after pregnancy.
What can your employer or your partner’s employer provide in benefits (e.g., sick pay) or work options (e.g., alternative work schedules, telecommuting)?
What would be the extra demands that multiples might place on your lifestyle?
Do you have friends and family who can help, if needed?
How long can you count on them to help?
Discuss single embryo transfer with your infertility specialist. The American Society for Reproductive Medicine (ASRM) and Society for Assisted Reproductive MedicineTechnology (SART) have released guidance on limits to the number of embryos to transfer to reduce the chances of having a multiple birth that you may wish to discuss with your infertility specialist.
In addition to talking with your infertility specialist, consider consulting the obstetrician who will help you through your pregnancy and the pediatrician who will take care of your children. You may want to discuss what to expect during the pregnancy, at delivery, and after giving birth if you have a multiple pregnancy, and use that information in deciding whether to ask for eSET.
Source: Centers for Disease Control and Prevention (CDC)
Additional Materials (2)
Embryonic Stem Cells
A colony of embryonic stem cells, from the H9 cell line (NIH code: WA09). Viewed at 10X with Carl Zeiss Axiovert scope.
(The cells in the background are mouse fibroblast cells. Only the colony in the centre are human embryonic stem cells)
Image by Ryddragyn/Wikimedia
How To Tell If Elective Single Embryo Transfer Is Right For You
Video by Attain Fertility/YouTube
Embryonic Stem Cells
Ryddragyn/Wikimedia
9:54
How To Tell If Elective Single Embryo Transfer Is Right For You
Attain Fertility/YouTube
What Can I Do to Avoid Multiple Birth?
Sensitive content
This media may include sensitive content
Recently-born triplets in an incubator
Image by Mike Blyth
Sensitive content
This media may include sensitive content
Recently-born triplets in an incubator
Recently-born triplets in an incubator
Image by Mike Blyth
What Can I Do to Avoid Multiple Birth?
If eSET seems appropriate to your circumstances, here are some things you can do.
If you are using insurance or other benefits for infertility care, check with your carrier to determine if they have a “case manager” or “benefits counselor” who can guide you through understanding coverage or special considerations for eSET services.
When selecting an ART provider, ask for information about the clinic’s policy and practices, as well as resources for decision making (e.g., counseling, case management).
Ask when you must make choices, or will have time to reconsider decisions, and how long you will have to make the decision (e.g., a day, an hour, a week).
There will be many decisions to make and uncertainty about the outcomes. In the end, it will remain important to take care of yourself, whether you will be the person who carries the pregnancy or a person who will become a parent through this process.
We understand the journey to overcoming infertility can be a long one, and making the decision to pursue ART can be overwhelming. It is important to know the implications of all decisions you will make, especially those that present health risks during and after pregnancy. You also need to give yourself time to consider if the options you seek are consistent with your needs, values, and beliefs.
Source: Centers for Disease Control and Prevention (CDC)
Additional Materials (4)
Pre-term-Factors
Pre-term-Factors
Image by CDC
Embryos at 44 Days (8 for Gestational Age) with Circulatory System
Through rotation and gradual imaging techniques, these human fetal visualizations show the vast amount of blood circulation needed to fuel the extraordinary growth of a 44-day-old fetus. The images at the bottom show only the circulatory system. The blood transports so many substances and does so many jobs it's hard to name them. Chiefly, though, it moves oxygen and food to all parts of the body while taking away waste chemicals. This process necessarily begins in the first week, and by twenty days watertight tubes branch throughout the embryo. The system grows \"ahead\" of the baby, proliferating in all directions like highways on a busy map, stimulating new areas of development. (Understanding how blood vessels are laid down in relation to cellular reproduction has provided some of the most hopeful recent insights against cancer.) After birth this network also serves to provide the baby with central heat, distributing warmth evenly through the body, from busy parts like the heart to cooler areas like still muscles. Please see our Infant Nutrition Health Center.
Image by TheVisualMD
Embryo 36 Day Old (Week 7 for Gestational Age) External and Internal Anatomy
Computer Generated Image from Micro-MRI, actual size of embryo = 6.0 mm. These images offer several perspectives of the internal and external development of an embryo at the beginning of six weeks. The age is calculated from the day of fertilization. The upper left image depicts a left anterolateral view of the external anatomy of the embryo. The liver region is semi-transparent so as to display the vasculature. The upper right image reveals the a right anterior view of the internal structures of the same embryo. The lower left image illustrates limb development as seen from a superior right view. The lower right image reveals the inner structural development from the same perpective. The cardiovascular system continues to develop at a rapid rate during this phase. The heart is the first functional organ to develop in the human embryo. It begins its existence as two simple tubes that quickly fuse to form a single chamber or heart tube that is busily pumping blood by the 23nd day. At around the 25th day, it exhibits four slightly bulged areas that represent the earliest heart chambers called sinus venosus, atrium, ventricle, bulbous cordis. During the next three weeks of development, the heart tube undergoes dramatic contortions so as to change its structure to become a four-chambered organ capable of acting as a double pump. This upper and lower right hand images depict the heart at the 36th day of development. The tubes have undergone the aforementioned changes and the heart is divided into its four definitive chambers. They will assume their adult positions in just one more month. These two images also offer a clear depiction of the vessels that convey blood to and from the heart and brain. By the fourth week of development, the heart is pumping blood through the rudimentary vascular system. The blood largely bypasses the liver (as seen in the upper left, upper right and lower right images). The umbilical vessels (posterior and anterior to the heart and liver) convey blood between the fetal circulation and the placenta where gas and nutrient exchanges occur with the mothers blood. Once the fetal circulatory system is formed, few vascular changes occur until birth and the umbilical vessels close. In the eye region (as represented by a red dot surrounded by a green ring the two upper and right lower images) the lens is almost completely closed and are starting to undergo retinal pigmentation. The growing nerve endings around the spinal cord are indicated in white in the two right hand images. The brain is also undergoing rapid differentiation as the irregularly shaped vesicles continue to form. The prominent uppermost bump in these images represent the future cerebellum. Continual development in the brain will bring about three major components, the forebrain, midbrain, and hindbrain. During this phase of development the limbs buds become visible as outpocketings from the body walls (as seen in the lower left-hand image). Six week old embryos, the distal portions of the limb buds become flattened to form the handplates and footplates. Fingers and toes will develop when a process called cell death separates the these structures into five distinct parts.
Image by TheVisualMD
Embryo 40 Day Old (Week 7 for Gestational Age) External and Internal Anatomy
Computer Generated Image from Micro-MRI, actual size of embryo = 8.0 mm - This image provides a frontal perspective of the embryo during its sixth week of development. The age is calculated from the day of fertilization. The head region is bent forward, characterized by the mass of the brain in comparison to the rest of the body. This promotes a C-shaped curvature. The end of the tail can be seen protruding upwards from the bottom of the embryo. The two lower limb buds can be seen protruding outward from the sides of the embryo. They will serve as the template for developing the legs.
Image by TheVisualMD
Pre-term-Factors
CDC
Embryos at 44 Days (8 for Gestational Age) with Circulatory System
TheVisualMD
Embryo 36 Day Old (Week 7 for Gestational Age) External and Internal Anatomy
TheVisualMD
Embryo 40 Day Old (Week 7 for Gestational Age) External and Internal Anatomy
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Elective Single-Embryo Transfer
Elective single-embryo transfer (eSET) is a procedure where a woman undergoing IVF chooses to have a single embryo transferred, selected from a larger number of available embryos. Learn how eSET reduces the risk of multiple births and related pregnancy complications.