Spinal muscular atrophy exists in children and varies in the severity of the disease. Those babies who suffer from the severe type of the disease experience more extreme symptoms when compared to the milder type of the SMA, which may not be found until the child is 18 months or older and experience placid symptoms. The symptoms found in babies include:

1. Rapid breathing
   Your baby could be suffering from rapid breathing, and their chest may appear to be bell-shaped. You may even notice the baby’s belly is active in a see-saw motion that pulls down the chest. By laying your baby on the back, the motion is more noticeable and in a repetitive state. Missed milestones and motor delays could be early warning signs of spinal muscular atrophy.
2. No anti-gravity movement
   When you see your baby struggling to lift the arms and legs while lying on the back or struggling to make their hands reach the mouth or find difficulty in raising the arms from the shoulders and the legs from the hips, you need to check with your doctor immediately. Your baby may lose the ability to lift the arms and legs after a certain time period and wiggle the toes without any movement of the legs.
3. Frog-like leg positioning
   When you see your baby does not have the ability to stretch its legs, they usually remain in a frog-like position. When your baby cannot extend the legs independently, they naturally begin resting in a frog-like position. They may not be able to lift their legs from the hips, which bends at the knees kicking. It is recommended to get your baby treated when only their toes are wiggling or when they rest excessively in a frog-like position.
4. Floppy head movements
   Head movement could be difficult for a baby suffering from SMA. Your baby cannot lift the head while they lay on the belly. When you lift your baby, you could feel like they might slip from your grip or seem floppy when lifted. Babies are known to have the ability to lift their heads and turn their heads in different directions during the first month of their birth. A baby that suffers from SMA uses their eyes for directions rather than their heads. This can be prevalent in infants and may appear in adults as well.
5. Weak limbs
   When you notice your baby does not have the ability to stretch, kick and straighten legs, or move legs independently in and out. The arms of your baby are usually anchored from their elbows or locked against the trunk. If he/she cannot move the lower portion of their fingers and arms, they may be suffering from acute SMA. Other early warning signs of spinal muscular atrophy you could look out for is when your baby is not able to reach to pick a toy.