What assessment, screening, and exam are recommended for a 20-month-old child during a well-child visit?

20-Month Well-Child Visit: Assessment, Screening, and Examination

At the 20-month well-child visit, perform comprehensive developmental surveillance with a validated parent-completed screening tool (Ages and Stages Questionnaire or Parents' Evaluation of Developmental Status), complete physical examination with growth parameters, vision screening including red reflex and ocular alignment testing, and provide anticipatory guidance on nutrition, safety, and developmental milestones. 1, 2, 3

Developmental Screening and Surveillance

Formal developmental screening is critical at this age, as clinical judgment alone misses approximately 45% of children eligible for early intervention. 2

• Use a validated, parent-completed developmental screening tool such as the Ages and Stages Questionnaire (ASQ) or Parents' Evaluation of Developmental Status (PEDS) 1, 2, 3
• While formal standardized screening is recommended at 9,18, and 30 months, developmental surveillance should occur at every visit including 20 months 2, 3
• Remain vigilant for early signs of autism spectrum disorder, though formal autism-specific screening with M-CHAT is recommended at 18 and 24 months 1, 2
• For premature infants, correct for gestational age by subtracting weeks born early from chronological age through at least 24 months 1

Common Pitfall: Do not rely on clinical observation alone—studies show referral rates increase by 224% when validated screening tools are used compared to physician judgment, with 67.5% of delayed cases missed without formal screening 4, 5

Physical Examination Components

Growth Assessment

• Measure and plot weight, length, and head circumference on appropriate growth charts 1, 2, 3
• Use corrected age for growth measures in extremely preterm and very preterm infants through 36 months 1
• Calculate body mass index starting at 2 years of age 2

Vision Screening

• Perform red reflex testing in a darkened room using direct ophthalmoscope—any asymmetry in color, brightness, or size warrants referral 1, 2
• Assess ocular alignment using corneal light reflex—any eye movement or asymmetry requires referral 1, 2
• Consider instrument-based screening at 18 months to assess risk 2

Hearing Surveillance

• Monitor auditory skills and developmental milestones consistent with age-appropriate expectations 1
• Ensure audiological assessment is planned by 24-30 months for infants with risk indicators (NICU stay >48 hours, ECMO, CMV infection) 1

Cardiovascular Assessment

• Blood pressure measurement is not routinely required at 20 months unless the child has obesity, renal disease, diabetes, history of aortic arch obstruction/coarctation, or is taking medications known to increase blood pressure 1

Head-to-Toe Examination

• Perform comprehensive examination including skin, HEENT, cardiovascular, respiratory, abdominal, genitourinary, musculoskeletal, and neurological systems 3, 6
• Assess for developmental dysplasia of the hips, though clinical examination sensitivity decreases after 3 months of age 7

Laboratory Screening

• Hemoglobin or hematocrit screening should have been completed at 12 months 2
• Risk assessment at 18 months determines if additional screening is needed 2
• No routine laboratory testing is required at 20 months unless indicated by history or examination findings 3

Immunization Review

• Review and update immunizations according to CDC schedule 1, 2
• The fourth dose of DTaP should be administered between 15-18 months with minimum 6-month interval from third dose 1, 2
• Ensure completion of MMR, varicella, hepatitis A, and Hib vaccines if not already administered 1

Common Pitfall: Do not administer DTaP-IPV/Hib (Pentacel) as the 4-6 year booster, as it is not indicated for that age 1

Anticipatory Guidance

Provide age-appropriate counseling on: 1, 3

• Nutrition: Transition from bottle to cup should be complete by 12 months; whole milk consumption; limiting juice to avoid dental caries and obesity 3
• Safety: Car seat should remain rear-facing until 2 years of age or until height/weight limit is reached; childproofing home 1, 3
• Dental health: Fluoride use; first dental visit should occur by 12 months 3
• Sleep patterns: Age-appropriate sleep schedules and routines 1
• Screen time: Should be avoided except for video chatting in children younger than 18 months 3

Maternal Mental Health Screening

• Screen for postpartum depression in mothers of infants up to 6 months of age 3
• At 20 months, this is typically not required unless concerns arise 3

Referral Criteria

Immediate referral is required for: 2

• Any child failing standardized developmental screening
• Absent expected motor milestones
• Loss of previously acquired skills
• Abnormal muscle tone findings
• Positive autism screening results
• Abnormal vision screening (asymmetric red reflex or ocular misalignment) 1, 2

Follow-Up Planning

• Schedule next well-child visit at 24 months 3
• Ensure formal developmental screening will occur at 24 months with autism-specific screening 2
• Document all findings, screening results, and anticipatory guidance provided 3