Developmental Milestones at 4 Months of Age
At 4 months, infants should demonstrate rolling from prone to supine, supporting themselves on elbows and wrists in prone position, keeping hands unfisted most of the time, playing with fingers at midline, and grasping objects. 1
Gross Motor Skills
- Rolling prone to supine is the key gross motor milestone expected at 4 months, representing advancement from the 2-month ability to simply lift head and chest 1, 2
- Supporting weight on elbows and wrists when placed on stomach demonstrates improved upper body strength and postural control 1
- Lifting head and chest when prone should be well-established by this age, as this skill emerges at 2 months 1, 2
- Head movements become more controlled after 3 months, with infants holding their head at body midline more consistently and demonstrating increased number, extent, and speed of head movements 3
Fine Motor Skills
- Hands should be unfisted most of the time, marking a transition from the reflexive fisted posture of younger infants 1
- Playing with fingers at midline demonstrates emerging hand awareness and bilateral coordination 1
- Grasping and reaching for objects represents the beginning of purposeful hand use, though the refined pincer grip does not develop until 9-12 months 1
Important Clinical Context
- These milestones represent mean ages of performance, so some normal variation exists, but marked delays beyond 4 months warrant attention 2
- For infants born before 36 weeks gestation, correct for prematurity for at least the first 24 months when assessing developmental milestones 1, 2
Red Flags Requiring Immediate Evaluation
- Regression or loss of any previously acquired motor skills is a major red flag requiring immediate evaluation for progressive neuromuscular disorders 1
- Inconsistent head control at 4 months suggests possible weakness or abnormal tone and warrants comprehensive neuromotor examination 1
- Asymmetry in movement patterns may indicate unilateral cerebral palsy and requires immediate evaluation 1
- Hypotonia, feeding difficulties, or dysmorphic features warrant earlier subspecialist referral 1
Surveillance Recommendations
- The American Academy of Pediatrics recommends continuous developmental surveillance at every well-child visit, with parents' concerns about development being elicited and documented 1, 2
- Formal standardized developmental screening is scheduled for 9,18, and 30 months, but concerns at any age should trigger immediate evaluation 1
- Watch the child's posture, play, and spontaneous motor function without stressful demands of performance during assessment 1