1. Physiologic Adaptations of the Newborn
Chapter 24
Physiologic Adaptations
of the Newborn

2. Transition to Extrauterine Life
First period of reactivity
Lasts up to 30 minutes after birth
Newborn’s heart rate increases to 160 to 180 beats/min
Decreases after 30 minutes
Decrease in motor activity after period

3. Transition to Extrauterine Life—cont’d
Second period of reactivity
Occurs 4 to 8 hours after birth
Tachycardia, tachypnea occur
Meconium passed
Increased muscle tone, changes in skin color, and mucous production

4. Physiologic Adaptations
Respiratory system
Initiation of breathing
Signs of respiratory distress
Maintaining adequate oxygen supply
Cardiovascular system
Heart rate and sounds
Blood pressure
Blood volume

5. Physiologic Adaptations—cont’d
Hematopoietic system
Red blood cells and hemoglobin
Leukocytes
Platelets
Blood groups

6. Physiologic Adaptations—cont’d
Gastrointestinal system
Digestion
Stools
Meconium
Feeding behaviors

7. Physiologic Adaptations—cont’d
Hepatic system
Iron storage
Carbohydrate metabolism
Jaundice
Coagulation
Immune system

8. Physiologic Adaptations—cont’d
Integumentary system
Caput succedaneum
Cephalhematoma
Subgaleal hematoma
Sweat glands
Desquamation
Mongolian spots
Nevi
Erythema toxicum

9. Physiologic Adaptations—cont’d
Skeletal system
At birth more cartilage then ossified bone
Neuromuscular system
Newborn reflexes
Neurologic assessment

10. Physical Assessment General appearance Vital signs
Baseline measurements of physical growth
Weight and length
Head circumference
Neurologic assessment

11. Behavioral Characteristics
Sleep-wake states
Other factors influencing behavior of newborns
Gestational age
Time
Stimuli
Medication

12. Behavioral Characteristics—cont’d
Sensory behaviors
Vision
Hearing
Smell
Taste
Touch

13. Behavioral Characteristics—cont’d
Response to environmental stimuli
Temperament
Habituation
Consolability
Cuddliness
Irritability
Crying

14. Key Points
Term infant’s various anatomic and physiologic systems have reached development and function that permits physical existence apart from mother
Infant has sensory capabilities that indicate state of readiness for social interaction
Appearance of jaundice during first day or persistence of jaundice for more than 7 days indicates a pathologic process

15. Key Points—cont’d
Heat loss in newborn may exceed capacity to produce heat and lead to metabolic and respiratory complications that threaten newborn’s well-being
Assessment of newborn requires data from the prenatal, intrapartal, and postpartal periods
Assessment proceeds systematically so each system is thoroughly evaluated

16. Key Points—cont’d
Some reflex behaviors are important for newborn’s survival
Personalities and behavioral characteristics of infants play major role in the ultimate relationship between infants and parents
Each full-term newborn has predisposed capacity to handle multitude of stimuli in external world