Trisomy 18 (Edwards Syndrome)
The short answer
Trisomy 18 (Edwards syndrome) is a chromosomal condition caused by an extra copy of chromosome 18, occurring in about 1 in 5,000 live births. It causes serious medical complications including heart defects, organ abnormalities, and severe developmental delays. While trisomy 18 is a life-limiting condition, each baby is an individual. Families are supported in making care decisions that align with their values, and many find profound meaning in the time they have with their child.
By Age
What to expect by age
Trisomy 18 is often diagnosed prenatally through screening tests and confirmed by amniocentesis or CVS. Babies born with trisomy 18 typically have low birth weight, a small head, clenched fists with overlapping fingers, heart defects (present in over 90%), and other organ abnormalities. Medical care in the newborn period focuses on comfort and quality of life. Some families choose comfort care only, while others pursue medical interventions. There is no single right approach — decisions should be guided by your family's values and the medical team's guidance.
About 40-60% of babies with full trisomy 18 survive beyond the first month, and about 5-10% survive their first year. Babies who survive often have significant medical needs including feeding support (often tube feeding), cardiac management, and respiratory support. Despite the challenges, many parents describe this time as precious. Palliative care teams can help manage symptoms and support quality of life for both the baby and the family.
Babies with trisomy 18 who survive to this age often show slow development and may achieve some social milestones like smiling and recognizing caregivers. Medical management continues to focus on comfort and treating symptoms. Some families choose interventions such as cardiac surgery, which can extend life in select cases. Support organizations for trisomy 18 families can connect you with other families who understand your experience.
A small percentage of children with trisomy 18 survive beyond their first birthday, and some live for several years, particularly those with mosaic trisomy 18 (where only some cells have the extra chromosome). These children have significant developmental delays but can form bonds with their families and respond to love and stimulation. Ongoing care involves a multidisciplinary team focused on comfort, quality of life, and family support.
What Should You Do?
When to take action
- Prenatal screening suggested trisomy 18 risk but diagnostic testing (amniocentesis) came back normal — false positives do occur
- Your baby was evaluated for trisomy 18 features but genetic testing confirmed normal chromosomes
- Your baby with mosaic trisomy 18 has some features but is more mildly affected than full trisomy 18
- Your baby with trisomy 18 is stable, comfortable, and responsive to your care and presence
- You received a prenatal screening result indicating increased risk for trisomy 18 and want to discuss diagnostic testing options
- Your baby has been diagnosed with trisomy 18 and you want to discuss care options and goals
- Your baby with trisomy 18 has changes in their comfort or medical status
- Your baby with trisomy 18 is in respiratory distress, has a blue or gray color, or appears to be in significant discomfort
- Your baby with trisomy 18 has stopped feeding, is unresponsive, or you have concerns about imminent decline — contact your palliative care or medical team immediately
Sources
Related Resources
Related Medical Concerns
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.
Air Quality and Baby Health
Babies and young children are more vulnerable to air pollution than adults because they breathe faster, their lungs are still developing, and they spend more time close to the ground where some pollutants concentrate. The EPA recommends keeping babies indoors when the Air Quality Index (AQI) exceeds 100 (orange level). During wildfire smoke events, keep windows closed, use air purifiers with HEPA filters, and monitor your child for coughing, wheezing, or difficulty breathing. Long-term exposure to air pollution can affect lung development.
Altitude Sickness in Babies
Babies and toddlers can experience altitude sickness when traveling above 5,000-8,000 feet (1,500-2,500 meters). Symptoms are harder to recognize in infants because they cannot describe how they feel. Watch for unusual fussiness, poor feeding, disrupted sleep, vomiting, and fast breathing. Gradual ascent is the best prevention. Most pediatricians recommend avoiding sleeping at very high altitudes (above 8,000 feet) with infants when possible, and descending immediately if symptoms appear.
Amblyopia (Lazy Eye) Treatment Timing
Amblyopia (lazy eye) is the most common cause of vision loss in children, affecting 2-3% of the population. It occurs when one eye develops weaker vision because the brain favors the other eye. Early detection and treatment are critical because the visual system is most responsive to treatment during early childhood. Treatment is most effective when started before age 7, though improvement is possible at older ages. Treatment options include patching the stronger eye, atropine eye drops, glasses, or a combination.