Neonatal Period
the first 28 days of life
What must occur immediately at birth to sustain extrauterine life?
Respiratory gas exchange along with circulatory modifications
What 4 areas do the newborn’s most dramatic and most rapid extrauterine transitions occur in?
Respiratory
Circulatory
Thermoregulation
Ability to stabilize blood glucose levels
What are the 4 primary challenges faced by the newborn?
- System-wide changes
- Neutral thermal environment
- Prevent cold stress
- Problems bilirubin conjugation and jaundice
When do the enzymatic pathways become fully active in the newborn?
3 months
Hepatic System Functions
Blood coagulation
Iron storage
Carbohydrate metabolism
Conjugation of bilirubin
Newborn iron stores are determined by what?
total body hemoglobin content and length of gestations
If the mother’s iron intake was adequate during pregnancy what does that mean for the newborn?
Sufficient iron has been stored in the newborn’s liver for 6 months
How long will the newborn have a sufficient iron supply if the mother had an adequate intake during pregnancy?
6 months
Glucose is an essential fuel for what?
Brain metabolism
What is one of the most frequent fetal-to-newborn problems?
Hypoglycemia
What is the main source of energy for the first several hours after birth?
Glucose
What will help to stabilize the newborn’s blood glucose levels?
initiating early breast or bottle feedings
Bilirubin
yellow/orange bile pigment produced by the breakdown of red blood cells
What is responsible for bilirubin elimination in utero?
the placenta and mother’s liver
Where is the principle source of bilirubin in the newborn?
Hemolysis and erythrocytes
What is the rate of bilirubin production in the newborns?
6-8 mg/kg/day
When will bilirubin decline to the adult level?
10-14 days after birth
Jaundice
increased amount of bilirubin in the bloodstream
Jaundice causes what?
yellowing of the skin, sclera, and mucous membranes
Extremely elevated levels of bilirubin in the first week of life can cause what?
Bilirubin encephalopathy
Bilirubin Encephalopathy
a permanent and devastating form of brain damage from extremely elevated levels of bilirubin in the first week of life
Common risk factors for Jaundice
- fetal-maternal blood group incompatibility
- prematurity
- asphyxia at birth
- insufficient intake of milk during breastfeeding
- drugs
- maternal gestational diabetes
- infrequent feedings
- male gender
- birth trauma
- previous siblings
- intrauterine infections
- Asians or Native American
TORCH Infections that can cause Jaundice
T-toxoplasmosis O-other viruses R-rubella C-cytomegalovirus H-herpes simplex virus
What are the 3 groups of jaundice based on?
Mechanism of accumulation
What are the 3 groups of Jaundice?
- Overproduction
- Decreased conjugation
- Impaired excretion
Overproduction of Bilirubin
Blood incompatibilities Drugs Trauma at birth Polycythemia Delayed cord clamping Breast milk jaundice
Decreased Bilirubin Conjugations
Physiologic Jaundice
Hypothyroidism
Breast-feeding
Impaired Bilirubin Excretion
Biliary obstruction Sepsis Hepatitis Chromosomal abnormality Drugs
Biliary obstructions associated with jaundice?
Biliary atresia
Gallstones
Neoplasm
Chromosomal abnormalities associated with Jaundice?
Turner syndrome
Trisomies 18 and 21
What is the most important adaptation to the gastrointestinal system?
Development of a mucosal barrier
What does the gastrointestinal mucosal barrier do?
Prevent the penetration of harmful substances present w/in the intestinal lumen
Colonization in the gut depends on what?
oral intake
What will harmful substances that penetrate the mucosal epithelial barrier under pathologic conditions cause?
inflammatory and allergic reactions
Colonization
occurs w/in 24 hours of age
required for the production of vitamin K
What microbes will be mechanically transferred from mom to baby after birth?
Environmental
Oral
Cutaneous
How are these microbes transmitted from mom to baby?
suckling, kissing, and caressing
What are effective methods of ensuring transmission of microbes from one generation to the next?
Proximity of birth canal to anus
Parental expression of neonatal care
What leads to regurgitation and uncoordinated peristaltic activity in newborn?
Cardiac sphincter and nervous control of stomach are immature
What can minimize regurgitation?
Avoiding overfeeding and stimulating frequent burps
Excreting fair amounts of lipids results in?
fatty stools
How many calories a day does the newborn need to gain weight?
110-120 kcal/kg/day from birth to 6 months
What is the newborn’s first stool?
Meconium
Meconium
greenish, black w/ tarry consistency
What is meconium made of?
amniotic fluid, shed mucosal cells, intestinal secretions, and blood
When is meconium usually passed?
w/in 12-24 hours of birth
Breastfed stools
yellow-gold, loose, stringy to pasty, sour smelling, seedy
Bottle-fed stools
yellow, yellow-green, loose, pasty, or formed, unpleasant odor
The glomeruli and nephrons are immature at birth resulting in what?
Reduced glomerular filtration rate and limited concentrating ability
What can make the newborn susceptible to dehydration and fluid overload?
Limited ability to concentrate urine and the reduced GFR
How many voidings per day are considered normal?
6-8
What will become stimuli for initiating respirations from a normal labor?
Hypercapnia
Hypoxia
Acidosis
Surfactant
surface-tension reducing lipoprotein found in the newborn’s lungs
What will surfactant prevent?
Alveolar collapse at the end of expiration
Loss of lung volume
Atelectasis
What is one of the most crucial adaptations the newborn makes at birth?
Adjusting from fluid-filled intrauterine environment to a gaseous extrauterine environment
How does the birth canal help eliminate fluid in the lungs?
intermittent compression of the thorax
After passing through the birth canal what will remove the rest of the fluid?
Pulmonary capillaries and the lymphatics
What happens if the fluid is removed to slowly or incompletely?
Transient tachypnea
What events have to happen before the newborn’s lungs can maintain respiratory function?
- Initiation of respiratory movement
- Expansion of the lungs
- Establishment of functional residual capacity
- Increased pulmonary blood flow
- Redistribution of cardiac output
Newborn Respiration Characteristics
- 30-60 breaths per minute
- irregular and shallow
- short periods of apnea
Signs of Respiratory Distress
cyanosis tachypnea grunting sternal retraction nasal flaring
Chest movements of the newborn should be?
symmetrical
Periodic Breathing
cessation of breathing that lasts 5-10 seconds w/o changes in color or HR
Average Newborn HR
110-160 bpm
The blood volume of the newborn depends on what?
The amount of blood transferred from the placenta at birth
Benefits of delayed cord clamping?
- improving cardiopulmonary adaptations
- preventing iron-deficient anemia
- increased iron stores
- increased BP
- improve oxygen transport
- increasing RBC flow
Fetus RBC vs Adult RBC
Fetus has more RBC’s per cubic millimeter than adults and have a higher affinity for oxygen at a lower oxygen pressure
Newborn RBC Lifespan
80-100 days
What is the initial method recommended for maintaining newborn body temp?
Skin to skin contact
Skin to skin should be the first line of treatment for what?
Hypothermia
Measure to reduce discomfort from painful procedure
Thermoregulation
process of maintaining the balance b/t heat loss and heat production in order to maintain core temp
Characteristics Predisposing Newborns to Heat Loss
- thin skin
- lack of shivering ability/voluntary muscle activity
- limited stores of fat=large body surface area
- No ability to adjust own clothes/blankets
- Cannot communicate if to hot or cold
Conduction
transfer of heat from object to object when the 2 objects are in direct contact w/ each other
Convection
flow of heat from body surface to cooler surrounding air or to air circulating over a body surface
Evaporations
loss of heat when liquid is converted to vapor
Radiation
loss of body heat to cooler, solid surfaces in close proximity but NOT direct contact
How do newborns produce heat?
Through nonshivering thermogenesis
Neutral Thermal Environment
body temp is maintained w/o an increase in metabolic rate or oxygen use
What will a neutral thermal environment promote?
- Growth and stability
- Conserves energy for basic bodily functions
- Minimizes heat and water loss
Nonshivering Thermogenesis
process in which brown fat is oxidized in response to cold exposure
Cold Stress
excessive heat loss
What will a newborn do in response to cold stress?
Use compensatory mechanisms such as nonshivering thermogenesis and tachypnea to maintain core body temp
Cold Stress can cause what?
- Depleted brown fat stores
- Increased oxygen needs
- Respiratory distress
- Hypoglycemia
- Metabolic Acidosis
- Jaundice
- Hypoxia
- Decreased surfactant production
How ling will maternal antibodies protect the newborn from certain infections?
6 months
What antibodies will the newborn receive from breast milk?
IgE, IgA, IgM, IgG
When will healthy newborns begin producing their own antibodies?
2-3 months
3 Purposes of Immune System Responses
- Defense
- Homeostasis
- Surveillance
All immune responses primarily involve what?
Leukocytes
What are the 2 categories of immune system responses?
Natural and Acquired Immunity
Natural Immunity
responses or mechanisms that do NOT require previous exposure to the microorganism or antigen to operate effectively
Examples of Natural Immunity
Physical barriers
Chemical barriers
Resident nonpathologic organisms
What are the 2 primary processes for Acquired Immunity?
- development of circulating immunoglobins
- formation of activated lymphocytes
Acquired immunity is absent until when?
Until after the first invasion by a foreign organism or toxin
Newborn’s immunologic ability depends heavily on which 3 immunoglobulins?
IgG, IgA, IgM
IgG
- Major immunoglobulin and most abundant
- Found in serum and interstitial fluid
- produces antibodies against bacteria, bacterial toxins, and viral agents
IgA
- second most abundant
- protects mucous membranes from viruses/bacteria
- found in GI/Respiratory tract, tears, saliva, colostrum, and breast milk
IgM
- found in blood and lymph fluid
- first to respond to infection
- major source of protection from blood-borne infections
What is the most important function of the skin?
provide a protective barrier b/t body and the environment
Functions of the Skin
- limits loss of water
- prevents absorption of harmful agents
- protects thermoregulation and fat storage
- protects against physical trauma
Neurologic development follows what patterns?
Cephalocaudal and proximal-distal patterns
Cephalocaudal Pattern
head to toe
Proximal-Distal Pattern
center to outside
What acute senses will the newborn have from early myelin development?
Hearing, smell, and taste
Hearing
well developed at birth; responds to noise by turning to sound
Smell
ability to distinguish mother’s breast milk and breast milk from others
Taste
ability to distinguish b/t sweet and sour by 72 hours old
Touch
sensitivity to pain; responds to tactile stimuli
Vision
incomplete at birth; maturation is dependent on nutrition and visual stimulation
Reflex
an involuntary muscle response to a sensory stimulus
What do reflexes indicate?
neurologic development and function
First Period of Reactivity
Begins at birth and lasts for 30 minutes-2 hours
How does the newborn act during the first period?
Alert, moving, and may appear hungry
Period of Decreased Responsiveness
From 30 minutes-120 minutes of age
How is the newborn during the period of decreased responsiveness?
“Sleep period”
Period of sleep or decreased activity
Second Period of Reactivity
Begins as the newborn awakens and shows interest in environmental stimuli
Lasts 2-8 hours
Neurobehavioral Response
how newborns react to the world around them
Orientation
response of newborns to stimuli
Habituation
ability to process and respond to auditory and visual stimuli ; ability to block out external stimuli
Motor Maturity
ability to control movements
Self-Quieting Ability
consolability
Social Behaviors
snuggling and cuddling
