Physical Assessment for a 3-Week-Old Baby
A comprehensive physical assessment for a 3-week-old baby should include evaluation of growth parameters, vital signs, neuromotor development, and systematic examination of all body systems to identify any abnormalities that could affect morbidity and mortality.
General Approach
- Create a comfortable environment for the infant
- Observe the baby before disturbing them (color, posture, spontaneous movements)
- Perform the examination in a systematic head-to-toe approach
- Ensure proper lighting and warm room temperature
Growth Parameters
- Measure and plot:
- Weight
- Length
- Head circumference
- Compare to birth measurements to assess growth trajectory
- Calculate percent change from birth weight 1
Vital Signs
- Temperature (axillary preferred with emollient to prevent skin damage) 1
- Heart rate (normal: 100-160 beats/minute)
- Respiratory rate (normal: 30-60 breaths/minute)
- Blood pressure (only if clinically indicated)
- Oxygen saturation (if indicated, use padding between monitor and skin) 1
Skin Assessment
- Color (observe for jaundice, pallor, cyanosis)
- Texture and turgor
- Rashes, birthmarks, or lesions
- Bruising or evidence of trauma
- If jaundice is present, consider measuring total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) 1
Head Examination
- Shape and symmetry
- Fontanelles (anterior and posterior) - size, tension, and pulsation
- Suture lines - check for craniosynostosis
- Scalp for lesions or abnormal hair patterns
- Head circumference (plot on growth chart)
Face and Neck
- Facial symmetry, dysmorphic features
- Eye examination:
- Red reflex (to rule out congenital cataracts)
- Pupillary response
- Conjunctiva for redness or discharge
- Eye movements and alignment
- Ears:
- Position and shape
- Response to sounds
- Nose:
- Patency of nares
- Breathing pattern
- Mouth:
- Palate integrity (cleft palate/lip)
- Tongue size and movement
- Presence of oral thrush
- Neck:
- Range of motion
- Masses or abnormal positioning
- Clavicles for fractures
Chest and Respiratory System
- Shape and symmetry of chest
- Respiratory effort and pattern
- Auscultation for breath sounds and any abnormal sounds
- Observe for retractions, nasal flaring, or grunting
Cardiovascular System
- Heart rate and rhythm
- Auscultation for murmurs (position, timing, intensity)
- Peripheral pulses (femoral, brachial)
- Capillary refill time (normal <3 seconds)
- Color of extremities
Abdomen
- Shape and contour
- Bowel sounds
- Palpation for masses or organomegaly (liver, spleen)
- Umbilical cord site (healing, signs of infection)
- Document pattern of voiding and stooling 1
Genitourinary System
- Male: testicular descent, penile abnormalities, inguinal hernias
- Female: labia, clitoris, vaginal discharge
- Urinary output (frequency and stream)
Musculoskeletal System
- Extremities for symmetry and movement
- Hip examination for developmental dysplasia (Ortolani and Barlow maneuvers)
- Spine for straightness and skin abnormalities
- Muscle tone and strength
Neurological Examination
- Level of alertness and responsiveness
- Primitive reflexes (Moro, rooting, sucking, palmar grasp)
- Tone assessment (ventral suspension in younger infant) 1
- Symmetry of movements
- Head control
- Observe for abnormal movements or tremors
Feeding Assessment
- Adequacy of intake (weight gain pattern)
- Breastfeeding or formula feeding technique
- Frequency and duration of feeds
- Presence of regurgitation or vomiting
Special Considerations
- Check newborn screening results 1
- Review immunization status
- Screen mother for postpartum depression 2
- Assess parent-infant bonding and interaction
Red Flags Requiring Urgent Attention
- Poor weight gain or excessive weight loss
- Lethargy or decreased responsiveness
- Fever or hypothermia
- Respiratory distress
- Persistent jaundice
- Abnormal tone or movements
- Poor feeding
- Bilious vomiting or abdominal distention 1
Documentation
Document all findings systematically, noting both normal findings and any abnormalities. Include growth parameters with percentiles and any parental concerns.
Remember that safe handling practices are essential during the examination to protect the infant's skin and prevent trauma 1. The physical assessment provides an opportunity to educate parents about normal development and care of their infant while screening for conditions that may require early intervention.