NURS 2866 - Physiologic and Behavioral Adaptations of the Newborn

What are the three stages of newborn transition?

First Period of Reactivity, Period of Decreased Responsiveness, Second Period of Reactivity.

What happens during the First Period of Reactivity?

Lasts up to 30 mins after birth; tachycardia, tachypnea, nasal flaring, crackles, grunting, retractions; ideal time to initiate breastfeeding.

What occurs in the Period of Decreased Responsiveness?

Decreased motor activity; lasts 60–100 mins; baby is sleepy and less responsive.

What defines the Second Period of Reactivity?

Occurs 2–8 hours after birth; lasts 10 mins to several hours; may show tachycardia, tachypnea, and usually passes meconium.

What stimulates the initiation of breathing?

Chemical, mechanical, thermal, sensory, and environmental factors at birth.

How do chemical factors initiate breathing?

Increased CO2 and decreased O2 during labor stimulate the respiratory center in the brain.

What is the role of prostaglandins in breathing?

Prostaglandins inhibit breathing; when the cord is clamped, prostaglandins drop and breathing is stimulated.

How do mechanical factors help initiate breathing?

Chest compression during vaginal delivery expels fluid and draws air into lungs.

How do thermal factors help initiate breathing?

Sudden drop in temperature after birth stimulates skin receptors, activating the respiratory center.

What are sensory/environmental factors in breathing?

Handling, suctioning, drying, lights, noise, and smells all help stimulate respiration.

What is surfactant?

A protein that reduces surface tension in alveoli, keeping them open during respiration.

Why is surfactant important?

Prevents alveolar collapse and decreases work of breathing.

Which infants are at higher risk for surfactant deficiency?

Preterm infants or sick term infants.
Signs of respiratory distress in a newborn?

What is acrocyanosis?

Bluish hands and feet; normal in the first 24 hours.

What cardiovascular changes happen after birth?

Closure of umbilical arteries/vein and ductus venosus, which become ligaments.

Where is the apical pulse located in newborns?

4th intercostal space.

Normal heart rate of a term newborn?

120–160 bpm; 80–100 bpm during sleep; up to 180 bpm when crying.

What might a murmur in a newborn indicate?

Often benign; if accompanied by poor feeding, apnea, or cyanosis, further evaluation is needed.

Normal newborn blood pressure?

Systolic 60–80 mmHg, Diastolic 40–50 mmHg.

What should the MAP (mean arterial pressure) equal?

The baby’s gestational age in weeks.

What is normal newborn blood volume?

80–100 mL/kg; may increase with delayed cord clamping.

Signs of cardiovascular problems in newborns?

Persistent tachycardia or bradycardia, cyanosis, skin color changes.

What is the normal WBC range in a newborn?

9,000–30,000 at birth; may rise to 24,000 in first few days.

Is WBC count a reliable indicator of infection in newborns?

No, not a good indicator on its own.

What makes newborns prone to heat loss?

Thin subcutaneous fat, close-to-surface blood vessels, large body surface area.

Four methods of heat loss?

Convection, radiation, evaporation, conduction.

Define convection.

Heat loss to cooler surrounding air.

Define radiation.

Heat loss to cooler objects near baby.

Define evaporation.

Heat loss when moisture evaporates from skin.

Define conduction.

Heat loss when in contact with cool surfaces.

How do newborns produce heat?

Thermogenesis by metabolizing brown fat, not by shivering.

Where is brown fat located?

Around neck, scapulae, axillae, kidneys, and spine.

What is cold stress?

Excessive heat loss leading to increased O2 and glucose use, leading to metabolic acidosis.

Why are preterm infants at greater risk for cold stress?

They have little to no brown fat.

What is the stomach capacity of a newborn on day 1, 3, and 7?

Day 1: 10 mL, Day 3: 30 mL, Day 7: 60 mL.

Why should parents not overfeed newborns?

Their stomach capacity is small and may cause regurgitation.

What is meconium?

The first stool; passed within 24–48 hours after birth.

What does meconium in utero indicate?

Possible fetal distress.

Why do glucose levels drop after birth?

Baby is removed from maternal glucose source at birth.

Normal glucose levels in the first hour?

55–60 mg/dL.

When should glucose levels be monitored?

SGA, LGA, preterm infants, infants of diabetic mothers, or signs of hypoglycemia.

Signs of hypoglycemia?

Jitteriness, lethargy, apnea, poor feeding.

What causes jaundice in newborns?

Excess bilirubin from RBC breakdown exceeds liver’s ability to conjugate.

When is jaundice visible?

Serum bilirubin 6–7 mg/dL; starts in head and moves down.

Why are newborns at higher risk for jaundice?

High RBC mass and shorter RBC lifespan.

Difference between physiologic and pathologic jaundice?

Physiologic appears after 24 hrs and resolves naturally; pathologic appears within 24 hrs and needs treatment.

Risk factors for jaundice?

Prematurity, breastfeeding.

Which antibodies are present in newborns?

IgG (from mom), IgM (made by baby), IgA (from breast milk).

What does IgG do?

Provides passive immunity from mother; crosses placenta starting at 14 weeks.

What does IgM do?

Produced by fetus; responds to bloodborne pathogens.

What does IgA do?

Found in breast milk; protects GI and respiratory tracts.

Signs of infection in newborns?

Temperature instability, lethargy, poor feeding, vomiting, diarrhea, respiratory distress signs.

What is vernix caseosa?

White, cheese-like protective skin coating; present after 35 weeks.

What is desquamation?

Skin peeling; more common in post-term infants.

What are Mongolian spots?

Bluish-black pigmentations on back or buttocks; common in darker skin tones.

What are nevi (stork bites)?

Flat pink spots; fade with time; no clinical significance.

What is erythema toxicum?

Newborn rash; transient and benign.

Why document Mongolian spots?

To avoid mistaking them for bruises later.

What causes vaginal discharge in female newborns?

Hormonal withdrawal; may be white or blood-tinged.

What is hypospadias?

Urethral opening on ventral side of penis.

What is epispadias?

Urethral opening on dorsal side of penis.

When should testes be palpable in scrotum?

By 40 weeks gestation.

What is molding?

Overlapping of cranial bones to fit through birth canal.

What is caput succedaneum?

Soft tissue swelling that crosses suture lines.

What is cephalhematoma?

Blood collection that does NOT cross suture lines.

What is subgaleal hemorrhage?

Bleeding that DOES cross suture lines.

Signs of developmental dysplasia of the hip?

Asymmetrical thigh folds, uneven knees, positive Ortolani/Barlow tests.

How many sleep-wake states are there?

Six—2 sleep (deep, light) and 4 awake (drowsy, quiet alert, active alert, crying).

What factors influence newborn behavior?

Gestational age, time of day, stimuli, and medications.

What can newborns see?

Objects up to 2.5 feet away.

How well do newborns hear?

Can hear and distinguish sounds.

What taste do newborns prefer?

Sweet (sucrose).

Why is touch important in newborns?

They are sensitive to touch all over the body.