My Baby Has a Sunken Chest (Pectus Excavatum)
The short answer
Pectus excavatum (sunken chest) is the most common chest wall deformity, affecting about 1 in 300-400 births. Mild cases are typically cosmetic and do not affect heart or lung function. It may become more noticeable with growth. Most cases do not need treatment, but your pediatrician should monitor it.
This is one of the most common questions parents ask. Searching for answers means you care.
By Age
What to expect by age
Pectus excavatum may be noticed at birth or become apparent in the early months. A mild depression in the sternum is common. Your pediatrician should note it and monitor over time.
The indentation may become more visible as your baby grows. If breathing seems normal and your baby is gaining weight and developing well, the condition is likely mild.
Continue monitoring. If the indentation seems to deepen or your child has breathing concerns during activity, mention it to your pediatrician.
Pectus excavatum may become more prominent during growth spurts. If it is moderate to severe, a pediatric surgeon can evaluate whether intervention is needed. Most mild cases require no treatment.
What Should You Do?
When to take action
- Mild, stable indentation.
- Normal breathing and activity tolerance.
- Normal growth and development.
- No heart or lung symptoms.
- Indentation seems to be deepening.
- Your child gets short of breath with activity.
- Heart racing or chest pain during exercise.
- Severe chest indentation with breathing difficulty.
- New onset breathing problems.
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
Related Physical Concerns
My Baby's Breastbone Sticks Out (Pectus Carinatum)
Pectus carinatum (protruding breastbone or "pigeon chest") is less common than pectus excavatum. In babies and toddlers, a slightly prominent sternum is often normal. True pectus carinatum typically becomes more noticeable during adolescent growth spurts. If present in infancy, your pediatrician should monitor it.
My Baby's Ribs Stick Out
Mild rib flaring (lower ribs that protrude slightly) is common in babies and toddlers, especially when lying down or with their arms up. It is often a normal anatomical variation, particularly in lean babies. However, significant rib flaring can sometimes indicate rickets (vitamin D deficiency) or core muscle weakness.
My Baby Seems to Use One Side More Than the Other
Babies should use both sides of their body fairly equally during the first 18 months of life. While slight preferences can be normal, a consistent pattern of favoring one side - using one arm much more than the other, crawling with one leg dragging, or turning the head predominantly one way - should always be discussed with your pediatrician. Early identification of asymmetry leads to the best outcomes.
My Baby Only Army Crawls
Army crawling (also called commando crawling) is a completely valid and normal way for babies to move. Many babies army crawl for weeks or even months before transitioning to hands-and-knees crawling, and some skip hands-and-knees crawling entirely. What matters is that your baby is independently mobile and exploring their environment.
One Side of My Baby's Body Moves Differently
Babies should generally use both sides of their body equally. If one side consistently moves differently, is weaker, stiffer, or less coordinated, this warrants evaluation. Asymmetric movement can indicate hemiplegia (cerebral palsy affecting one side), brachial plexus injury, or other neurological conditions that benefit from early therapy.
My Baby Crawls Unevenly
While some variation in crawling patterns is normal, consistently favoring one side or dragging one limb while crawling warrants attention. Babies should use both arms and both legs relatively equally when crawling. Persistent asymmetry could indicate muscle tone differences, hip issues, or neurological concerns that benefit from early evaluation.