Edwards Syndrome (Trisomy 18): Symptoms, Causes, Diagnosis, Treatment, Survival Rates and When to Seek Emergency Care — What You Need to Know
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
Quick Answer: What Is Edwards Syndrome and How Is It Diagnosed?
Edwards syndrome, also known as trisomy 18, is a very severe genetic condition that affects how a child's body develops and grows, caused by an extra copy of chromosome 18. Children with the condition have low birth weight, multiple birth defects and defining physical characteristics. It is diagnosed during pregnancy through ultrasound and confirmed by tests like amniocentesis or chorionic villus sampling (CVS). There is no cure; treatment is tailored to each child and may include cardiac care, a feeding tube, orthopaedic treatment and psychosocial support, with comfort care common in the most severe cases.
TL;DR
Edwards syndrome (trisomy 18) is a very severe genetic condition that affects how a child's body develops and grows, causing physical growth delays during fetal development. It occurs when a person has an extra copy of chromosome 18 — a random, unpredictable event that is not the result of anything parents did before or during pregnancy.
It is rare: an estimated 1 out of every 5,000 to 6,000 live births, and more common during pregnancy (1 out of every 2,500 pregnancies). At least 95% of fetuses do not survive full term due to complications, so pregnancies often end in miscarriage or stillbirth. Children diagnosed with trisomy 18 have low birth weight, multiple birth defects and defining physical characteristics, and life expectancy is short due to several life-threatening complications. Children who survive past their first year may face severe intellectual challenges.
Diagnosis begins during pregnancy with routine ultrasound screening, and tests such as amniocentesis (15–20 weeks), chorionic villus sampling (10–13 weeks) or blood screenings (after 10 weeks) confirm the diagnosis; a heart ultrasound follows birth. Treatment is unique for each child — cardiac treatment, assisted feeding, orthopaedic care and psychosocial support — and there is no cure. Prevention is not possible, though preimplantation genetic testing combined with in vitro fertilization can significantly reduce the chance of having an affected child.
Survival varies: 60–75% of babies born with Edwards syndrome survive to their first week, 20–40% to their first month, and no more than 10% past their first year. Of those who survive past their first birthday, children go on to live fulfilling lives with significant support from their family and caretakers, as most never learn to walk or talk.
Limitation: this article uses only prevalence and survival figures published in the cited source; no statistics are invented or drawn from outside research.
Key Facts at a Glance
Cause: an extra copy of chromosome 18 (trisomy 18), random and unpredictable.
Frequency (live births): about 1 in every 5,000 to 6,000.
Frequency (pregnancies): about 1 in every 2,500.
Full-term survival: at least 95% of fetuses do not survive full term.
Cure: none — treatment is supportive and symptom-focused.
Survival to first week: between 60% and 75%.
Survival to first year: no more than 10%.
What Is Edwards Syndrome (Trisomy 18)?
Edwards syndrome, also known as trisomy 18, is a very severe genetic condition that affects how your child's body develops and grows. Children diagnosed with trisomy 18 have a low birth weight, multiple birth defects and defining physical characteristics.
The condition causes physical growth delays during fetal development. Life expectancy for children diagnosed with Edwards syndrome is short due to several life-threatening complications of the condition. Children who survive past their first year may face severe intellectual challenges.
Who Does Edwards Syndrome Affect?
Edwards syndrome can affect anyone. The condition occurs when a person has an extra copy of chromosome 18, which is random and unpredictable. The likelihood that a parent will have a child with Edwards syndrome increases with maternal age at the time of pregnancy.
If a parent had a child with Edwards syndrome and becomes pregnant again, it is unlikely they will have another child diagnosed with the same condition — no more than 1%.
How Common Is Edwards Syndrome (Trisomy 18)?
Edwards syndrome occurs in an estimated 1 out of every 5,000 to 6,000 live births. The condition is more common during pregnancy (1 out of every 2,500 pregnancies), but most (at least 95%) fetuses do not survive full term due to complications from the diagnosis, so pregnancies can end in miscarriage or babies are stillborn.
What Are the Symptoms of Edwards Syndrome (Trisomy 18)?
Symptoms of Edwards syndrome typically include poor growth before and after birth, multiple birth defects and severe developmental delays or learning problems. Symptoms are present during pregnancy and after your child is born.
Symptoms During Pregnancy
Your healthcare provider will look for signs of Edwards syndrome during a prenatal ultrasound:
Very little fetal activity (reduced movement observed on ultrasound).
A single artery in your umbilical cord.
A small placenta.
Birth defects detected on prenatal imaging.
Too much amniotic fluid surrounding your fetus (polyhydramnios).
An Edwards syndrome diagnosis can result in a live birth, but trisomy 18 most often causes a miscarriage during the first three months of pregnancy or the baby is stillborn.
Characteristics After Birth
After your baby is born, your child likely has physical characteristics of Edwards syndrome:
Decreased muscle tone (hypotonia).
Low-set ears.
Internal organs forming or functioning differently (heart and lungs).
Severe intellectual disabilities.
Overlapping fingers and/or clubfeet.
Small physical size (head, mouth and jaw).
A weak cry and minimal response to sound.
Severe Symptoms
Because children diagnosed with Edwards syndrome have underdeveloped bodies, the side effects of the condition have serious and often life-threatening consequences:
Congenital heart disease — present at birth; affects nearly 90% of children.
Kidney disease — present at birth.
Respiratory failure — breathing abnormalities; a leading cause of premature death.
Gastrointestinal tract and abdominal wall issues — birth defects of the digestive tract and abdominal wall.
Hernias — abnormal openings in the abdominal wall.
Scoliosis — spinal curvature affecting movement.
Issues relating to the heart affect nearly 90% of children diagnosed with Edwards syndrome and are the leading cause of premature death among infants who have the condition, next to respiratory failure.
What Causes Edwards Syndrome (Trisomy 18)?
Having three copies of chromosome 18 instead of the typical two causes Edwards syndrome. All humans have 46 chromosomes that divide into 23 pairs. Chromosomes carry your DNA in cells, which tells your body how to form and function as its instruction manual. You receive one set of chromosomes from each of your parents.
During egg and sperm formation, when chromosome pairs are supposed to divide, there is a chance that a chromosome pair will not divide (as if they are too sticky) and both copies will be included in the egg or sperm. When fertilization happens, those two copies join one from the other parent so the result is three copies in total. The incorrect number of chromosomes is unpredictable and random and is not the result of something the parents did before or during pregnancy.
When a third copy of a cell joins a pair, a trisomy occurs. Trisomy means "three bodies." If someone receives an Edwards syndrome diagnosis, they have a third copy of chromosome 18 in their cells.
How Is Edwards Syndrome (Trisomy 18) Diagnosed?
Diagnosis of Edwards syndrome begins during pregnancy, and confirmation of the diagnosis occurs either before or after your baby is born. Your healthcare provider will look for signs during a routine ultrasound screening, including fetal activity, the amniotic fluid surrounding your fetus and the size of your placenta. If signs of a genetic condition are present, your healthcare provider may offer additional testing for confirmation.
Routine ultrasound screening: during pregnancy; checks fetal activity, amniotic fluid and placenta size.
Amniocentesis: between 15 and 20 weeks; a small sample of amniotic fluid is taken to identify potential health conditions.
Chorionic villus sampling (CVS): between 10 and 13 weeks; a small sample of cells from your placenta is taken to look for genetic conditions.
Blood screenings: after 10 weeks; assess whether your child has common extra chromosome conditions, including trisomy 18.
Heart ultrasound: after birth; your provider examines your child's heart to identify and treat any heart-related conditions.
How Is Edwards Syndrome (Trisomy 18) Treated?
Often, the condition is so severe that babies who survive being born are treated with comfort care. But treatment for Edwards syndrome is unique for each child, based on the severity of their diagnosis. There is no cure for Edwards syndrome. Treatment might include:
Comfort care: common when the condition is very severe.
Cardiac treatment: heart problems affect nearly all cases; not all babies are eligible for surgery, but some might be.
Assisted feeding: a feeding tube might be necessary to address early feeding problems due to delayed physical growth.
Orthopaedic treatment: bracing or surgery for spinal problems like scoliosis that impact movement.
Psychosocial support: to help you, your family and your child cope with loss or navigate the complex diagnosis.
What Is the Prognosis (Survival Rate) for Edwards Syndrome?
There is no cure for Edwards syndrome. Almost all pregnancies end in miscarriage or stillbirth. Of those pregnancies surviving into the third trimester, nearly 40% of babies diagnosed with Edwards syndrome do not survive during labor, and nearly one-third of the surviving babies deliver preterm.
To first week: between 60% and 75% survive.
To first month: between 20% and 40% survive.
Past first year: no more than 10% survive.
Children born with Edwards syndrome will need specialized care to address their unique symptoms immediately after they are born. The survival rate is low, especially if your child has delayed organ development or a congenital heart condition. Out of the 10% who survive past their first birthday, children go on to live fulfilling lives with significant support from their family and caretakers, as most never learn to walk or talk.
How Can I Reduce My Risk of Having a Child with Edwards Syndrome?
Edwards syndrome is the result of a genetic mutation and there is no way to prevent the condition. However, if you qualify for a combination of genetic testing and in vitro fertilization (preimplantation genetic testing), you can significantly reduce the chance of having a child with Edwards syndrome. If you plan on becoming pregnant and want to understand your risk of having a child with a genetic condition, talk with your healthcare provider about genetic testing.
When Should You See Your Healthcare Provider?
One of the side effects of having a child with Edwards syndrome is a risk of miscarriage or a loss of pregnancy. If you are pregnant, contact your healthcare provider if you experience any symptoms of a miscarriage: abdominal pain, chills, cramping, heavy bleeding (similar to a heavy period), or lower back pain.
Emergency — ER or call 911 immediately: if your child born with Edwards syndrome breathes quickly or very slowly or not at all, has a blue or purple color to their skin or lips, has a fast heartbeat, has trouble eating, or has swelling throughout their body, take them to the emergency room or call 911 immediately.
What Questions Should You Ask Your Doctor?
What are my risks of having a child with a genetic condition?
What type of treatment is available to target my child's symptoms?
What can I do during pregnancy to make sure my baby is healthy?
Caring for a Child with Edwards Syndrome
Edwards syndrome is among the most severe genetic diagnoses a family can receive. There is no cure, and most pregnancies end in miscarriage or stillbirth; of babies born with trisomy 18, only a minority survive past their first year. Yet for the children who do, life can still be fulfilling: the 10% who survive past their first birthday go on to live meaningful lives with significant support from their family and caretakers. Care is entirely individualized — cardiac treatment where surgery is possible, feeding tubes for early feeding problems, bracing or surgery for scoliosis, and psychosocial support for the whole family as they navigate the diagnosis or cope with loss.
Two safety signals matter most: pregnant parents should contact their provider for any miscarriage symptoms, and any baby with trisomy 18 who breathes abnormally, turns blue or purple, has a fast heartbeat, cannot eat, or swells throughout the body needs the emergency room or a 911 call immediately.
An Edwards syndrome (trisomy 18) diagnosis might be overwhelming due to the severe complications that arise from the condition. Your healthcare provider will support you and your family along the journey, helping you navigate your child's diagnosis or coping with loss. If you plan on becoming pregnant, discuss genetic testing with your healthcare provider to identify your risk of having a child with a genetic condition.
Take the next step. If you are planning a pregnancy and want to understand your risk of a genetic condition, talk with your healthcare provider about genetic testing; if you qualify, preimplantation genetic testing combined with in vitro fertilization can significantly reduce the chance of having a child with Edwards syndrome. If you are pregnant and experience abdominal pain, chills, cramping, heavy bleeding or lower back pain, contact your provider. For a child with trisomy 18, seek emergency care immediately for abnormal breathing, blue or purple skin or lips, fast heartbeat, feeding trouble or whole-body swelling.
Frequently Asked Questions About Edwards Syndrome
What is Edwards syndrome?
Edwards syndrome, also known as trisomy 18, is a very severe genetic condition that affects how your child's body develops and grows.
Why is it called trisomy 18?
It occurs when a person has an extra copy of chromosome 18. Trisomy means "three bodies" — a third copy joins a pair of chromosomes.
What causes Edwards syndrome?
Having three copies of chromosome 18 instead of the typical two. The extra chromosome is random and unpredictable and is not the result of something the parents did before or during pregnancy.
Who does Edwards syndrome affect?
It can affect anyone; the likelihood increases with maternal age at the time of pregnancy.
Is it my fault if my child has trisomy 18?
No — the incorrect number of chromosomes is unpredictable and random and isn't the result of something the parents did.
How common is Edwards syndrome?
An estimated 1 out of every 5,000 to 6,000 live births.
How common is it during pregnancy?
1 out of every 2,500 pregnancies; at least 95% of fetuses do not survive full term.
What are the chances of having another child with trisomy 18?
If a parent had a child with Edwards syndrome and becomes pregnant again, it is unlikely — no more than 1%.
Who discovered Edwards syndrome?
John Hilton Edwards, et al., in 1960, after researching a newborn with multiple congenital complications.
What are the symptoms during pregnancy?
Very little fetal activity, a single artery in the umbilical cord, a small placenta, birth defects, and too much amniotic fluid (polyhydramnios).
What is polyhydramnios?
Your fetus being surrounded by too much amniotic fluid.
What happens to most pregnancies with trisomy 18?
Almost all end in miscarriage or stillbirth; trisomy 18 most often causes a miscarriage in the first three months or the baby is stillborn.
What are the characteristics after birth?
Decreased muscle tone (hypotonia), low-set ears, internal organs forming or functioning differently (heart and lungs), severe intellectual disabilities, overlapping fingers and/or clubfeet, small physical size (head, mouth and jaw), and a weak cry with minimal response to sound.
What is hypotonia?
Decreased muscle tone.
What severe complications can occur?
Congenital heart disease and kidney disease present at birth, breathing abnormalities (respiratory failure), gastrointestinal tract and abdominal wall issues and birth defects, hernias, and scoliosis.
How common are heart problems in Edwards syndrome?
Issues relating to the heart affect nearly 90% of children and are the leading cause of premature death, next to respiratory failure.
How is Edwards syndrome diagnosed during pregnancy?
Through routine ultrasound screening followed by confirmatory tests — amniocentesis (15–20 weeks), chorionic villus sampling (10–13 weeks), or blood screenings (after 10 weeks).
What is amniocentesis?
Between 15 and 20 weeks, your provider takes a small sample of amniotic fluid to identify potential health conditions.
What is chorionic villus sampling (CVS)?
Between 10 and 13 weeks, your provider takes a small sample of cells from your placenta to look for genetic conditions.
What happens after birth?
Your provider examines your child's heart via ultrasound to identify and treat any heart-related conditions.
Is there a cure for Edwards syndrome?
No. There is no cure for Edwards syndrome.
How is trisomy 18 treated?
Treatment is unique for each child based on severity: cardiac treatment, assisted feeding (possibly a feeding tube), orthopaedic treatment (bracing or surgery for scoliosis), psychosocial support, and often comfort care when the condition is very severe.
What is the survival rate for Edwards syndrome?
Between 60% and 75% survive to their first week; between 20% and 40% to their first month; no more than 10% past their first year.
What happens to babies born with trisomy 18?
They need specialized care immediately after birth. Nearly 40% of third-trimester pregnancies end with the baby not surviving labor, and nearly one-third of surviving babies deliver preterm.
What is life like for children who survive past their first year?
Out of the 10% who survive past their first birthday, children go on to live fulfilling lives with significant support from their family and caretakers, as most never learn to walk or talk.
Can Edwards syndrome be prevented?
No — it is the result of a genetic mutation. However, preimplantation genetic testing combined with in vitro fertilization can significantly reduce the chance of having a child with Edwards syndrome if you qualify.
When should I contact my healthcare provider?
If you are pregnant, for any miscarriage symptoms: abdominal pain, chills, cramping, heavy bleeding (similar to a heavy period), or lower back pain.
When should I call 911 for a child with Edwards syndrome?
Immediately if the child breathes quickly or very slowly or not at all, has blue or purple skin or lips, has a fast heartbeat, has trouble eating, or has swelling throughout their body.
References
Medical Disclaimer: This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. If you think you may have a medical emergency, call 911 or your local emergency number immediately.
Comments