What assessments are recommended for a 4-month-old patient in primary care to monitor growth and development?

Assessments for a 4-Month-Old in Primary Care

At the 4-month well-child visit, perform comprehensive growth monitoring, complete physical examination with developmental assessment, vision and hearing screening, and administer scheduled immunizations according to CDC guidelines. 1, 2

Growth Assessment

Plot weight, length, and head circumference on WHO growth charts (recommended for children under 24 months), using the 2.3rd and 97.7th percentiles (±2 standard deviations) rather than the traditional 5th and 95th percentiles to identify abnormal growth patterns. 1 The WHO charts are specifically designed with breastfed infants as the standard, recognizing that breastfeeding is the recommended feeding method. 1

• For premature infants, correct for gestational age by subtracting the number of weeks born early from chronological age when assessing both growth and developmental milestones through at least 24 months of life. 2
• For extremely preterm (<28 weeks) and very preterm (28 to <32 weeks) infants, extend age correction for growth measures through 36 months of corrected age. 2

Complete Physical Examination

Head and Neurological Assessment

• Examine fontanelles, head shape, and measure head circumference for any abnormalities. 2
• Evaluate tone, posture, primitive reflexes, and spontaneous movements. 2
• Assess for any involuntary movements or coordination impairments. 2

Vision Screening

• Perform red reflex testing (Brückner test) to detect abnormalities of the ocular media and assess symmetry of reflexes. 2
• Conduct external inspection of ocular and periocular structures. 2
• Assess pupillary examination and evaluate fixation and following behavior. 2
• Note that poor eye contact after 8 weeks warrants further assessment. 2

Hearing Assessment

• Review newborn hearing screening results if not previously completed. 2
• If screening was not performed or concerns exist, arrange formal brainstem auditory evoked potential response testing. 1, 2

Cardiopulmonary Examination

• Auscultate heart for rate, rhythm, and presence of murmurs. 2
• Auscultate lungs for air entry and abnormal sounds. 2
• Assess respiratory rate and pattern. 2

Abdominal and Genitourinary Examination

• Palpate abdomen for organomegaly, masses, or tenderness. 2
• Assess umbilical cord site for complete healing and absence of infection. 2
• Examine external genitalia for abnormalities. 2
• Assess urinary stream in males and genital appearance in females. 2

Musculoskeletal Examination

• Examine hips for signs of developmental dysplasia using Ortolani and Barlow maneuvers. 2

Skin Assessment

• Assess skin color, perfusion, and presence of rashes or lesions. 2

Ear, Nose, and Throat

• Examine tympanic membranes. 2
• Assess nares for patency and discharge. 2
• Examine oral cavity, including palate and tongue. 2

Developmental Assessment

By 4 months, infants should demonstrate specific motor and social milestones that must be assessed at this visit. 2

Expected Developmental Milestones

• Ability to lift head and chest when placed in prone position. 2
• Making eye contact and demonstrating social smiling. 2

Structured Developmental Screening Questions

Ask parents these specific questions recommended by the American Academy of Pediatrics: 2

• "Is there anything your child is not doing that you think he or she should be able to do?"
• "Is there anything your child is doing that you are concerned about?"
• "Is there anything your child used to be able to do that he or she can no longer do?"

Formal Screening Considerations

• Consider using validated screening tools such as Ages and Stages Questionnaire or Child Development Inventories for systematic assessment. 1
• Do not rely solely on clinical judgment, as physician impression alone misses 45% of children eligible for early intervention. 3
• Assess overall appearance, activity level, and interaction with caregivers. 2

Required Screenings and Laboratory Review

• Review metabolic/newborn screening results if not previously reviewed. 2
• Assess for risk factors warranting additional screening. 2

Immunizations

Administer age-appropriate immunizations according to CDC recommended schedule at 4 months. 2 This typically includes:

• DTaP (diphtheria, tetanus, pertussis)
• IPV (inactivated poliovirus)
• Hib (Haemophilus influenzae type b)
• PCV (pneumococcal conjugate)
• Rotavirus

For infants born to HBsAg-positive mothers, ensure proper hepatitis B vaccine series continuation. 2

Anticipatory Guidance

• Discuss basic infant care including bathing, skin care, and temperature measurement. 2
• Reinforce safe sleep practices: back to sleep, firm surface, no co-sleeping. 4
• Review appropriate car safety seat use (rear-facing). 4
• Ensure caregivers understand developmental expectations for the next period. 2

Common Pitfalls to Avoid

• Do not skip age correction for premature infants when assessing developmental milestones, as this leads to unnecessary referrals or missed delays. 2
• Do not delay referral for infants showing developmental delays based on corrected age—these warrant immediate referral. 2
• Do not overlook hearing assessment, as formal testing should be completed if not done at birth or if concerns exist. 1, 2
• Avoid using clinical judgment alone for developmental assessment without structured screening questions or validated tools. 3