Infants 4 months of age are expected to develop certain physical and mental skills. These skills are called milestones.

PHYSICAL AND MOTOR SKILLS

The typical 4-month-old should:

• Show a slowing of weight gain to approximately 20 grams per day
• Demonstrate the fading of the infant reflexes (Moro reflex, asymmetric tonic neck reflex, rooting reflex, and Perez reflex)
• Have almost no head lag while in a sitting position
• Be able to sit up straight if propped
• Raise head 90 degrees when placed on stomach
• Be able to roll from back to one side
• Try to reach objects with hands (may commonly overshoot)
• Play with rattle when it's placed in the hands, but won't be able to pick it up if dropped
• Be able to grasp rattle with both hands
• Be able to place objects in mouth

SENSORY AND COGNITIVE SKILLS

A 4-month-old is expected to:

• Have well-established close vision
• Have beginning eye-hand coordination
• Be able to make the consonant sounds:
  • N
  • K
  • P
  • G
  • B
• Be able to laugh out loud
• Anticipate feeding when able to see a bottle (if bottle-fed)
• Begin to show memory
• Demand attention by fussing

PLAY

You can encourage development through play:

• Place the baby in front of a mirror
• Provide bright-colored toys to hold
• Repeat sounds the infant makes
• Help the infant roll over
• Use a swing or stroller