NM717 MODULE 5 NEWBORN MIDWIFERY CARE OF THE
NEWBORN KELSEY REVIEW GUIDE P. 214-220, 222-223, 226-
231 EXAM QUESTIONS AND VERIFIED CORRECT ANSWERS
GRADED A++ LATEST UPDATE
Immediate extrauterine newborn transition
—immediate transition from intrauterine to extrauterine life
Immediate extrauterine newborn transition depends on changes in four major
areas:
—respiration,
—circulation,
—thermoregulation, and
—glucose regulation
Biochemical Factors in initiation of respiration
—relative hypoxia at the end of labor
Physical stimuli Factors in initiation of respiration
—cold, gravity, pain, light, noise
Physiologic Factor in initiation of respiration
Recoil from pressure on thorax while passing through vagina
Sustained respiration depends on coordinated response of the
following
,a. Central nervous system (CNS) respiratory center
b. Aortic and carotid chemoreceptors
c. Thoracic mechanoreceptors
d. Diaphragm and respiratory muscles
Initial breathing serves the following purposes
a. Assist in conversion from fetal to extrauterine circulation
b. Clear lungs of fluid
c. Establish lung volume and expand alveoli
Characteristics of normal newborn respiration
a. Respiratory rate 30 to 60 breaths per minute
b. Irregular/fluctuating pattern
c. Diaphragmatic and abdominal breathing
d. Obligate nose breathing
e. Absence of nasal flaring, grunting, and retractions
Circulatory changes
Transition from fetal to adult circulation begins with clamping of the umbilical cord and
continues throughout the first weeks of life
Characteristics of fetal circulation
a. Low-pressure system, including placenta (low-resistance circuit)
b. Minimal circulation to lungs; bypassed via foramen ovale and ductus arteriosus
c. Foramen ovale favors circulation of most oxygen-rich blood to the brain
Transition from fetal to neonatal circulation
,a. Increased systemic resistance due to loss of placental circuit
b. Increased pressure in left atrium causes functional closure of foramen ovale
c. Initial respiration opens pulmonary vasculature, favoring circulation to lungs
d. Increased oxygenation of circulating blood causes constriction and functional closure
of ductus arteriosus
e. Absence of placental circulation closes ductus venosus
Thermoregulation Mechanisms of neonatal heat loss
a. Convection
b. Conduction
c. Radiation
d. Evaporation
Thermoregulation Neonate creates heat in three ways:
a. Shivering (inefficient)
b. Muscle activity (limited benefit)
c. Thermogenesis by metabolism of brown adipose tissue (BAT)
High risks infants with ineffective Thermogenesis
(1) BAT stores are decreased in preterm and growth-restricted fetuses
(2) Hypoglycemia decreases efficiency of BAT metabolism
Thermoregulation Consequences of cold stress
a. Increased oxygen consumption, leading to relative hypoxia and acidosis
b. Metabolism of BAT and release of fatty acids decreases pH
c. Increased use of glucose, depletion of glycogen stores, and hypoglycemia
d. Worsening hypoglycemia and acidosis may result in respiratory distress
, Thermoregulation Management/Interventions to promote
a. Skin-to-skin contact on mother's chest or abdomen with blanket over both
b. Prewarm blankets and resuscitation area
c. Dry the newborn immediately and replace wet blankets
d. Regulate room temperature and minimize exposure to air convection
e. Postpone newborn bath at least two hours
f. Keep newborn warm and wrapped
Glucose regulation Glycogen stores
a. Predominantly in liver
b. Accumulated in third trimester
Glucose regulation Risk factors for neonatal hypoglycemia
a. Infants of diabetic mothers
b. Small for gestational age (SGA) or large for gestational age (LGA)
c. Preterm or post-term
d. Intrapartum—perinatal acidemia, beta-agonist tocolysis, IV glucose administration
e. Maternal substance abuse
Glucose regulation in the healthy neonate
a. Normal physiologic decrease in blood glucose appears to be essential to stimulate
physiologic processes promoting glucose production
(1) Lowest at 1-1.5 to 5 hours after birth
(2) Stabilizes at three to four hours after birth
(3) neonate hypoglycemia definition is controversial. Guidelines underscore the need to
measure glucose levels as soon as possible in symptomatic infants; if symptomatic and
NEWBORN KELSEY REVIEW GUIDE P. 214-220, 222-223, 226-
231 EXAM QUESTIONS AND VERIFIED CORRECT ANSWERS
GRADED A++ LATEST UPDATE
Immediate extrauterine newborn transition
—immediate transition from intrauterine to extrauterine life
Immediate extrauterine newborn transition depends on changes in four major
areas:
—respiration,
—circulation,
—thermoregulation, and
—glucose regulation
Biochemical Factors in initiation of respiration
—relative hypoxia at the end of labor
Physical stimuli Factors in initiation of respiration
—cold, gravity, pain, light, noise
Physiologic Factor in initiation of respiration
Recoil from pressure on thorax while passing through vagina
Sustained respiration depends on coordinated response of the
following
,a. Central nervous system (CNS) respiratory center
b. Aortic and carotid chemoreceptors
c. Thoracic mechanoreceptors
d. Diaphragm and respiratory muscles
Initial breathing serves the following purposes
a. Assist in conversion from fetal to extrauterine circulation
b. Clear lungs of fluid
c. Establish lung volume and expand alveoli
Characteristics of normal newborn respiration
a. Respiratory rate 30 to 60 breaths per minute
b. Irregular/fluctuating pattern
c. Diaphragmatic and abdominal breathing
d. Obligate nose breathing
e. Absence of nasal flaring, grunting, and retractions
Circulatory changes
Transition from fetal to adult circulation begins with clamping of the umbilical cord and
continues throughout the first weeks of life
Characteristics of fetal circulation
a. Low-pressure system, including placenta (low-resistance circuit)
b. Minimal circulation to lungs; bypassed via foramen ovale and ductus arteriosus
c. Foramen ovale favors circulation of most oxygen-rich blood to the brain
Transition from fetal to neonatal circulation
,a. Increased systemic resistance due to loss of placental circuit
b. Increased pressure in left atrium causes functional closure of foramen ovale
c. Initial respiration opens pulmonary vasculature, favoring circulation to lungs
d. Increased oxygenation of circulating blood causes constriction and functional closure
of ductus arteriosus
e. Absence of placental circulation closes ductus venosus
Thermoregulation Mechanisms of neonatal heat loss
a. Convection
b. Conduction
c. Radiation
d. Evaporation
Thermoregulation Neonate creates heat in three ways:
a. Shivering (inefficient)
b. Muscle activity (limited benefit)
c. Thermogenesis by metabolism of brown adipose tissue (BAT)
High risks infants with ineffective Thermogenesis
(1) BAT stores are decreased in preterm and growth-restricted fetuses
(2) Hypoglycemia decreases efficiency of BAT metabolism
Thermoregulation Consequences of cold stress
a. Increased oxygen consumption, leading to relative hypoxia and acidosis
b. Metabolism of BAT and release of fatty acids decreases pH
c. Increased use of glucose, depletion of glycogen stores, and hypoglycemia
d. Worsening hypoglycemia and acidosis may result in respiratory distress
, Thermoregulation Management/Interventions to promote
a. Skin-to-skin contact on mother's chest or abdomen with blanket over both
b. Prewarm blankets and resuscitation area
c. Dry the newborn immediately and replace wet blankets
d. Regulate room temperature and minimize exposure to air convection
e. Postpone newborn bath at least two hours
f. Keep newborn warm and wrapped
Glucose regulation Glycogen stores
a. Predominantly in liver
b. Accumulated in third trimester
Glucose regulation Risk factors for neonatal hypoglycemia
a. Infants of diabetic mothers
b. Small for gestational age (SGA) or large for gestational age (LGA)
c. Preterm or post-term
d. Intrapartum—perinatal acidemia, beta-agonist tocolysis, IV glucose administration
e. Maternal substance abuse
Glucose regulation in the healthy neonate
a. Normal physiologic decrease in blood glucose appears to be essential to stimulate
physiologic processes promoting glucose production
(1) Lowest at 1-1.5 to 5 hours after birth
(2) Stabilizes at three to four hours after birth
(3) neonate hypoglycemia definition is controversial. Guidelines underscore the need to
measure glucose levels as soon as possible in symptomatic infants; if symptomatic and
