Developed by D. Ann Currie, RN, MSN

Physiological Responses of the Newborn to BirthRespiratory Adaptations: Mechanical changes Chemical changes Thermal changes Sensory changes

Fetal and Neonatal Circulation

Normal Term Newborn Cord Blood

Neutral Thermal Environmental Temperatures

Physiologic Adaptations to Extrauterine Life

Newborn Urinalysis Values

Cardiovascular Adaptations Decreased pulmonary vascular resistance and

increased blood flowIncreased systemic pressure and closure of

ductus venosusIncreased left atrium and decreased right

atrium pressureClosure of foramen ovale

Reversal of blood flow through ductus arteriosus and increased PO2Closure of ductus arteriosus

Transitional circulation: conversion from fetal to neonatal circulation.

Fetal-neonatal circulation. A, Pattern of blood flow and oxygenation in fetal circulation. B, Pattern of blood flow and oxygenation in transitional circulation of the newborn. C, Pattern of blood flow and oxygenation in neonatal circulation.

Fetal Laboratory Value ChangesDecreased erythropoietin productionRise of hemoglobin concentrationPhysiologic anemia of infancyLeukocytosisDecreased percentage of neutrophils

Thermogenesis in the NewbornLarge body surface area compared to massTypes of heat loss

ConvectionRadiationEvaporationConduction

Convection

Radiation

Evaporation

Conduction

Types of Bilirubin Unconjugated bilirubinConjugated bilirubinTotal bilirubin

Conjugation and Excretion of Bilirubin Bilirubin is transported in blood via albuminBilirubin is transferred into the hepatocytesAttachment of unconjugated bilirubin to

glucuronic acidExcreted into bile ducts, then into the

common duct and duodenumBacteria transform it into urobilinogen and

stercobilinogenBilirubin is excreted in urine and stool

Jaundice

Physiologic Jaundice Accelerated destruction of fetal RBCsIncreased amounts of bilirubin delivered

to liverInadequate hepatic circulation

Impaired conjugation of bilirubinDefective uptake of bilirubin from the

plasmaDefective conjugation of the bilirubin

Physiologic Jaundice (continued) Increased bilirubin reabsorption

Defect in bilirubin excretionIncreased reabsorption of bilirubin from the

intestine

Liver Adaptations Iron content stored in liverLow carbohydrate reservesMain source of energy is glucoseLiver begins to conjugate bilirubinLack of intestinal flora results in low levels of

vitamin K

GI Adaptations Sufficient enzymes except for amylaseDigests and absorbs fats less efficientlySalivary glands are immatureStomach has capacity of 50-60 mLCardiac sphincter is immature

Fluid and Electrolyte Balance

Less able to concentrate urineLimited tubular reabsorption of waterLimited excretion of solutesLimited dilutional capabilities

Immunologic Responses in the Newborn

IgG – passive acquired immunity via placentaIgM – usually not passively transferred

Elevated levels may indicate fetal antigenic activity in utero

IgA – passive acquired immunity via colostrum

Periods of Reactivity First period of reactivitySleep phaseSecond period of reactivity

Mother and baby gaze at each other. This quiet alert state is the optimal state for interaction

Behavioral and Sensory Capabilities

HabituationOrientationAuditoryOlfactoryTasting and SuckingTactile

End of Part 1