Physical Development

Pectus Deformity (Chest Wall Shape) in Babies

Medically reviewed by Dr. Sarah Chen, MD, FAAP · Board-Certified Pediatrician

Content reviewed against published AAP, NIH, CDC guidelines

Editorial policy

Last reviewed:

Your baby's physical development is unique, and concerns about pectus deformity (chest wall shape) in babies, here is what you need to know.

The short answer

Pectus deformities are variations in the shape of the chest wall. Pectus excavatum (sunken or "funnel" chest) is a depression in the breastbone, while pectus carinatum ("pigeon" chest) is a protrusion. Both are relatively common, affecting about 1 in 300-400 children. In babies, a visible or prominent xiphoid process (the small cartilage at the bottom of the breastbone) is very common and is not a pectus deformity. Most mild pectus findings in infancy are monitored without treatment.

Key takeaways

  • Pectus deformities are variations in the shape of the chest wall. Pectus excavatum (sunken or "funnel" chest) is a depression in the breastbone, while pectus carinatum ("pigeon" chest) is a protrusion. Both are relatively common, affecting about 1 in 300-400 children. In babies, a visible or prominent xiphoid process (the small cartilage at the bottom of the breastbone) is very common and is not a pectus deformity. Most mild pectus findings in infancy are monitored without treatment.
  • Usually normal when: A small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward
  • Call your doctor if: You notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty
  • Varies by age — see the age-by-age breakdown below
“Supervised tummy time is recommended daily from the time the baby comes home from the hospital to help prevent flat head syndrome and to strengthen neck and shoulder muscles.”
— Back to Sleep, Tummy to Play, American Academy of Pediatrics (AAP)

This is one of the most common questions parents ask. Searching for answers means you care.

What Parents Should Know

According to AAP, NIH, CDC guidelines, pectus deformities are variations in the shape of the chest wall. Pectus excavatum (sunken or "funnel" chest) is a depression in the breastbone, while pectus carinatum ("pigeon" chest) is a protrusion. Both are relatively common, affecting about 1 in 300-400 children. In babies, a visible or prominent xiphoid process (the small cartilage at the bottom of the breastbone) is very common and is not a pectus deformity. Most mild pectus findings in infancy are monitored without treatment. At 0-6 months, many parents notice that their baby's breastbone looks prominent or that there is a small bump or dip at the bottom of the sternum. In most cases, this is the xiphoid process, a normal piece of cartilage that is simply more visible in thin babies. True pectus excavatum (a noticeable funnel-shaped dip in the center of the chest) can be present from birth and is usually mild. Your pediatrician will monitor it at well-child visits. It is generally considered normal when a small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward. However, you should contact your pediatrician promptly if you notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty.

Sources: [1], [2], [3]

Normal vs. Concerning

Usually Normal
Worth Discussing
A small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward
You notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty
A mild, shallow dip in the center of the chest that does not affect breathing
Your baby is breathing rapidly, grunting, or appears to be working hard to breathe
Visible ribs in a thin baby, which is normal and not a chest wall deformity
Your child tires very easily during physical activity and has a noticeable chest deformity
The chest shape looking slightly asymmetric, which is common and usually harmless
A sudden change in chest shape appears after an injury

By Age

What to expect by age

0-6 months

Many parents notice that their baby's breastbone looks prominent or that there is a small bump or dip at the bottom of the sternum. In most cases, this is the xiphoid process, a normal piece of cartilage that is simply more visible in thin babies. True pectus excavatum (a noticeable funnel-shaped dip in the center of the chest) can be present from birth and is usually mild. Your pediatrician will monitor it at well-child visits.

6-12 months

As your baby grows, a mild pectus excavatum may become more or less noticeable. In most cases, it does not affect breathing, heart function, or development. Pectus carinatum (chest protrusion) is rarely noticed in infancy and more commonly becomes apparent during the growth spurt of adolescence. If you notice your baby's chest seems to pull inward significantly when breathing, mention this to your pediatrician.

1-3 years

Mild pectus excavatum in toddlers is common and typically does not require treatment. The chest wall is still very flexible and may change shape as your child grows. If the dip appears to be getting deeper or your child seems to tire easily during physical activity, further evaluation may be recommended. Treatment (bracing or surgery) is rarely considered before school age and is usually reserved for moderate to severe cases.

What to Tell Your Pediatrician

  • Describe when you first noticed pectus deformity (chest wall shape) in babies and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if you notice a noticeable depression or protrusion in your baby's chest that seems more than mild.
  • Mention if the chest wall seems to change shape when your child breathes or exerts effort.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

What Should You Do?

When to take action

Probably normal when...
  • A small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward
  • A mild, shallow dip in the center of the chest that does not affect breathing
  • Visible ribs in a thin baby, which is normal and not a chest wall deformity
  • The chest shape looking slightly asymmetric, which is common and usually harmless
Mention at your next visit when...
  • You notice a noticeable depression or protrusion in your baby's chest that seems more than mild
  • The chest wall seems to change shape when your child breathes or exerts effort
  • You want reassurance about your baby's chest shape at a well-child visit
  • A family member has pectus excavatum or carinatum
Act now when...
  • You notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty
  • Your baby is breathing rapidly, grunting, or appears to be working hard to breathe
  • Your child tires very easily during physical activity and has a noticeable chest deformity
  • A sudden change in chest shape appears after an injury

What You Can Do at Home

  • Keep track of when you notice pectus deformity (chest wall shape) in babies — noting the time of day, duration, and any triggers can help your pediatrician.
  • Remember that a small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward — this is generally within the range of normal.
  • At 0-6 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
  • Provide plenty of supervised floor time and tummy time to support your baby's physical development.
  • While monitoring at home, seek immediate care if you notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty.

My Baby Is Breathing Fast

Babies normally breathe faster than adults. A normal respiratory rate for a newborn is 30-60 breaths per minute, slowing to 20-40 by age 1. Brief episodes of faster breathing during excitement, crying, or feeding are normal. However, persistently rapid breathing (tachypnea) at rest, especially with other signs of respiratory distress, may indicate a lung or heart problem that needs prompt evaluation.

My Baby's Spine Looks Curved

A gentle C-shaped curve when your baby is held in a seated position is completely normal, because babies' spinal muscles are still developing. True spinal abnormalities in infants are rare. However, a visible curve when your baby is lying flat, a bony bump along the spine, or a curve that seems rigid should be evaluated by your pediatrician.

My Baby's Belly Button Bulges When Crying

This is almost always an umbilical hernia, which is very common (occurring in about 1 in 5 babies) and usually harmless. It happens when a small opening in the abdominal muscles near the belly button doesn't close completely after birth. The bulge you see is intestine pushing through when baby cries, strains, or coughs. Most umbilical hernias close on their own by age 2-5 without any treatment.

Milestone

Month-by-Month Development

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Guide

When to Call the Doctor

General guide on when to call the pediatrician, visit urgent care, or go to the ER.

Frequently asked questions

Is pectus deformity (chest wall shape) in babies normal?
Pectus deformities are variations in the shape of the chest wall. Pectus excavatum (sunken or "funnel" chest) is a depression in the breastbone, while pectus carinatum ("pigeon" chest) is a protrusion. Both are relatively common, affecting about 1 in 300-400 children. In babies, a visible or prominent xiphoid process (the small cartilage at the bottom of the breastbone) is very common and is not a pectus deformity. Most mild pectus findings in infancy are monitored without treatment.
When should I call the doctor about pectus deformity (chest wall shape) in babies?
You notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty Your baby is breathing rapidly, grunting, or appears to be working hard to breathe Your child tires very easily during physical activity and has a noticeable chest deformity
When is pectus deformity (chest wall shape) in babies normal?
A small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward A mild, shallow dip in the center of the chest that does not affect breathing Visible ribs in a thin baby, which is normal and not a chest wall deformity
What causes pectus deformity (chest wall shape) in babies?
Pectus deformities are variations in the shape of the chest wall. Pectus excavatum (sunken or "funnel" chest) is a depression in the breastbone, while pectus carinatum ("pigeon" chest) is a protrusion. Both are relatively common, affecting about 1 in 300-400 children. In babies, a visible or prominent xiphoid process (the small cartilage at the bottom of the breastbone) is very common and is not a pectus deformity. Most mild pectus findings in infancy are monitored without treatment. Common explanations include: A small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward. A mild, shallow dip in the center of the chest that does not affect breathing.
What should I mention to my pediatrician about pectus deformity (chest wall shape) in babies?
You should mention pectus deformity (chest wall shape) in babies at your next visit if: You notice a noticeable depression or protrusion in your baby's chest that seems more than mild. The chest wall seems to change shape when your child breathes or exerts effort. You want reassurance about your baby's chest shape at a well-child visit.
Is pectus deformity (chest wall shape) in babies normal at 0-6 months?
Many parents notice that their baby's breastbone looks prominent or that there is a small bump or dip at the bottom of the sternum. In most cases, this is the xiphoid process, a normal piece of cartilage that is simply more visible in thin babies. True pectus excavatum (a noticeable funnel-shaped dip in the center of the chest) can be present from birth and is usually mild. Your pediatrician will monitor it at well-child visits.
Is pectus deformity (chest wall shape) in babies normal at 6-12 months?
As your baby grows, a mild pectus excavatum may become more or less noticeable. In most cases, it does not affect breathing, heart function, or development. Pectus carinatum (chest protrusion) is rarely noticed in infancy and more commonly becomes apparent during the growth spurt of adolescence. If you notice your baby's chest seems to pull inward significantly when breathing, mention this to your pediatrician.
Should I go to the ER for pectus deformity (chest wall shape) in babies?
Seek emergency care if you notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty, or if your baby is breathing rapidly, grunting, or appears to be working hard to breathe. When in doubt, call your pediatrician's after-hours line for guidance.
Does pectus deformity (chest wall shape) in babies go away on its own?
In many cases, pectus deformity (chest wall shape) in babies resolves on its own, especially when a small bump at the bottom of the sternum (xiphoid process) that is more visible when your baby leans forward. By 1-3 years, mild pectus excavatum in toddlers is common and typically does not require treatment. The chest wall is still very flexible and may change shape as your child grows. If the dip appears to be getting deeper or your child seems to tire easily during physical activity, further evaluation may be recommended. Treatment (bracing or surgery) is rarely considered before school age and is usually reserved for moderate to severe cases.
AAPNIHCDC

References

  1. [1]American Academy of Pediatrics. Pectus Excavatum and Pectus Carinatum. HealthyChildren.org. AAP
  2. [2]National Library of Medicine. Pectus Excavatum. StatPearls. NIH
  3. [3]Centers for Disease Control and Prevention. Birth Defects: Structural. CDC

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Pectus Deformity (Chest Wall Shape) in Babies.

Things to mention

  • Describe when you first noticed pectus deformity (chest wall shape) in babies and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if you notice a noticeable depression or protrusion in your baby's chest that seems more than mild.
  • Mention if the chest wall seems to change shape when your child breathes or exerts effort.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

Observations to share

  • You notice a noticeable depression or protrusion in your baby's chest that seems more than mild
  • The chest wall seems to change shape when your child breathes or exerts effort
  • You want reassurance about your baby's chest shape at a well-child visit

Urgent signs to report immediately

  • You notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty
  • Your baby is breathing rapidly, grunting, or appears to be working hard to breathe
  • Your child tires very easily during physical activity and has a noticeable chest deformity

My notes

From ismybabyalright.com — free, evidence-based baby health guides

All content follows our editorial policy and is reviewed against published clinical guidelines.

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Bottom line

Most cases of pectus deformity (chest wall shape) in babies are normal. Talk to your pediatrician if you notice significant chest retractions (the skin pulling in between or below the ribs) with every breath, which could indicate breathing difficulty.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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My Baby Is Breathing Fast

Babies normally breathe faster than adults. A normal respiratory rate for a newborn is 30-60 breaths per minute, slowing to 20-40 by age 1. Brief episodes of faster breathing during excitement, crying, or feeding are normal. However, persistently rapid breathing (tachypnea) at rest, especially with other signs of respiratory distress, may indicate a lung or heart problem that needs prompt evaluation.

My Baby's Spine Looks Curved

A gentle C-shaped curve when your baby is held in a seated position is completely normal, because babies' spinal muscles are still developing. True spinal abnormalities in infants are rare. However, a visible curve when your baby is lying flat, a bony bump along the spine, or a curve that seems rigid should be evaluated by your pediatrician.

My Baby's Belly Button Bulges When Crying

This is almost always an umbilical hernia, which is very common (occurring in about 1 in 5 babies) and usually harmless. It happens when a small opening in the abdominal muscles near the belly button doesn't close completely after birth. The bulge you see is intestine pushing through when baby cries, strains, or coughs. Most umbilical hernias close on their own by age 2-5 without any treatment.

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