Congenital scoliosis is a sideways curve of the spine caused by vertebrae that don’t form correctly before birth. Unlike the more common idiopathic scoliosis that develops during adolescence, congenital scoliosis originates during the first weeks of pregnancy, when the bones of the spine are just beginning to take shape. It affects roughly 0.5 to 1 in every 1,000 live births, though some screening studies suggest the true number may be closer to 1.8 per 1,000.
How Congenital Scoliosis Develops
The vertebrae of the spine form between the 4th and 6th week of gestation. During this narrow window, something disrupts the normal process, and one or more vertebrae end up misshapen, partially formed, or fused together. The baby is born with these structural abnormalities already in place, even if the curve isn’t noticed right away.
The malformations fall into two broad categories. The first is a failure of formation, where part or all of a vertebra simply doesn’t develop. This can produce a wedge-shaped vertebra or a “hemivertebra,” which is essentially half a vertebra. Because one side of the spine has less bone than the other, the column tilts. The second category is a failure of segmentation, where two or more vertebrae that should be separate end up fused together on one side. This creates a bony bar that prevents normal growth on that side while the opposite side keeps growing, gradually pulling the spine into a curve. Some children have a mix of both types, which tends to cause more significant curvature over time.
What Causes the Vertebrae to Malform
In most cases, no single cause is identified. The condition is not typically inherited in a straightforward way, but genetics play a role. Researchers have pinpointed several genes involved in vertebral development, with one of the best-studied being TBX6, a gene that helps regulate how the repeating segments of the spine form during embryonic growth. Certain mutations in TBX6, particularly when a child inherits both a rare disabling mutation and a common risk variant, can directly cause congenital scoliosis. Deletions of an entire region of chromosome 16 that includes TBX6 have also been found in affected children.
Beyond TBX6, genes involved in the Notch signaling pathway (a communication system cells use to coordinate development) and genes related to cilia function have been linked to vertebral malformations. Environmental factors during early pregnancy, such as poorly controlled diabetes, are also considered possible contributors, though proving a direct connection in individual cases is difficult.
Associated Health Conditions
Because the spine forms at the same time as several other organ systems, children with congenital scoliosis often have abnormalities elsewhere in the body. The heart, kidneys, and spinal cord are the most commonly affected. Doctors typically screen for these conditions once a vertebral malformation is found, even if the child seems healthy otherwise.
Some children with congenital scoliosis fit a broader pattern called VACTERL association, which describes a cluster of birth differences affecting the vertebrae, anus, heart, windpipe and esophagus, kidneys, and limbs. Around 80% of children with VACTERL have spinal anomalies, roughly half have heart defects (such as holes between heart chambers), and about half have kidney problems like a missing kidney, a misplaced kidney, or blocked urine flow. Not every child with congenital scoliosis has VACTERL, but the overlap is common enough that a thorough evaluation of other organ systems is standard.
Spinal cord abnormalities deserve special attention. Conditions like a tethered spinal cord or split spinal cord can accompany congenital vertebral defects, and these may need to be addressed before any treatment for the scoliosis itself. An MRI of the full spine is a routine part of the workup for this reason.
How It’s Diagnosed
Some cases are picked up on prenatal ultrasound, but many are first noticed at birth or during infancy when a parent or doctor spots an asymmetry in the trunk, uneven shoulders, or a visible curve. Physical signs like a skin dimple, a tuft of hair, or a small fatty lump over the spine can hint at underlying vertebral or spinal cord problems.
X-rays confirm the diagnosis by showing the shape and number of the malformed vertebrae. An MRI provides a detailed look at the spinal cord and surrounding soft tissues. CT scans are sometimes used to map complex bony anatomy before surgery. The severity of the curve is measured using the Cobb angle, a standard measurement taken from X-rays that expresses the degree of curvature.
How Curves Progress Over Time
Not all congenital curves worsen. The risk of progression depends heavily on the type and location of the malformation. A single hemivertebra with normal growth plates on either side may stay relatively stable for years. A unilateral bar (vertebrae fused on one side) opposite a hemivertebra is one of the most aggressive combinations, with curves that can worsen rapidly during growth spurts.
Because the behavior of each curve is so variable, monitoring is a core part of management. Children with mild, stable curves may only need X-rays every six to twelve months to track any changes. The key concern is catching progression early, particularly before and during the rapid growth phases of early childhood and adolescence.
Treatment Options
Treatment depends on the type of malformation, how fast the curve is progressing, and how much growing the child still has to do.
Observation
Stable curves with small Cobb angles, generally under 20 degrees, are often monitored without active treatment. Bracing, which is a mainstay for idiopathic scoliosis, has limited effectiveness in congenital scoliosis because the problem is a structural bone defect rather than a flexible curve. Braces can sometimes help manage compensatory curves that develop above or below the malformed area, but they won’t correct the malformed vertebra itself.
Surgery
Surgery is the primary treatment when curves are progressing or are already severe. The goal is to stop the curve from getting worse while preserving as much spinal growth and trunk length as possible. Several surgical approaches exist, and the right one depends on the child’s age and anatomy.
For young children whose spines still have years of growing ahead, growth-friendly techniques are often preferred. One option is a curved metal device called a VEPTR (vertical expandable prosthetic titanium rib), which attaches to the ribs, spine, or pelvis with hooks on each end. It gently straightens the spine and separates compressed ribs so the lungs have room to grow. As the child gets taller, the device needs to be lengthened through a small incision in the back, typically every six to eight months. Traditional growing rods work on a similar principle, and some children receive a combination of both.
For older children or specific malformations, a hemivertebra can sometimes be surgically removed in a single procedure, which directly eliminates the source of the imbalance. Spinal fusion, where two or more vertebrae are permanently joined together, is another option, particularly for curves that have become large or rigid. Surgeons try to fuse as few segments as possible to preserve flexibility and allow the rest of the spine to keep growing.
Impact on Lung Development
One of the most important concerns with congenital scoliosis, especially when it appears in the upper back (thoracic spine), is its effect on the chest and lungs. The lungs develop rapidly in the first years of life, and a severe spinal curve or fused ribs can physically restrict how much the chest cavity can expand. This condition, sometimes called thoracic insufficiency syndrome, can limit lung capacity well into adulthood if left untreated. Growth-friendly surgical devices like VEPTR were specifically designed to address this problem by keeping the chest wall expanding during the critical years of lung growth.
What Daily Life Looks Like
Most children with mild congenital scoliosis live active, unrestricted lives. The condition itself doesn’t cause pain in young children, though some adults with uncorrected or severe curves may develop back discomfort over time. Children who undergo growth-friendly surgery will have a period of regular surgical adjustments, which can be disruptive, but between procedures they typically return to most normal activities. After final fusion surgery, recovery usually takes several months, with gradual return to full activity.
Long-term outcomes vary widely. A child with a single stable hemivertebra may never need surgery and function with little to no limitation. A child with complex, multi-level defects and associated organ problems will likely need a coordinated team of specialists throughout childhood. Early detection and consistent monitoring remain the most reliable way to keep curves manageable and protect lung development during the years when it matters most.