The following guideline describes the various physical, cognitive, emotional, and social developmental changes and milestones to be expected during the first year of life.
It is of utmost importance to remember that the timeline is approximate, not absolute. Each child develops at his or her own pace, and some stages may occur earlier or later.

Differences between the timing in this guideline and your child may exist, but do not necessarily mean that there is a problem with your baby's development. Any concerns, however, should be discussed with your physician.

Physical

• Growth
  • Growth rate is still significant, but not as rapid as in the first 2 months
  • Posterior fontanelle ("soft spot") closes
• Movement and Activity
  • Lifts head (45°) for a sustained time when lying on stomach
  • Continued lag on raising head when pulled to sitting position from lying on back
  • Hands fisted half of the time
• Sensory
  • Will follow objects, consciously turn head 180°

Social

• Smiles voluntarily ("social smile") in response to appropriate stimuli (familiar faces or voices)
• Recognizes facial expressions
• Communication
  • Cries approximately 3 hours/day
  • Coos, makes single-syllable sounds

3 MONTHS OLD

Physical

• Growth
  • Gains 1¼ lbs/month
  • Length inc. 2 cm/month
• Movement and Activity
  • Minimal delay on raising head when pulled to sitting position from lying on back (bobbing)
  • Will reach for objects but misses while lying on back; waves at objects
  • Lifts head and chest when lying on stomach; rests on arms
  • Rolls side-to-side
  • Hands mostly unfisted
  • Small circular limb movements
  • Sleeping approximately 14 hours/day, with 9-10 occurring at night
• Sensory
  • Explores own body

Cognitive

• Will look at area where an object used to be (no sense of object permanency)

Social/Emotional

• Increased eye contact
• Listens to music
• Appropriate facial expressions in response to emotions (anger, fear, joy)
• Mimics others' facial expressions
• Increased awareness/interest in surroundings
• Distracted during nursing
• Shows different emotions (anger, fear, joy)
• Communication
  • Varied types of crying
  • Says "ahh"