Transition to Extrauterine Life Flashcards
What does the fetus depend on for gas exchange?
The placenta
The placenta facilitates gas exchange between maternal and fetal blood.
What percentage of fetal cardiac output flows through the placenta?
40%
This highlights the importance of placental circulation in fetal development.
What is the ductus venosus?
A fetal shunt that directs blood from the umbilical vein to the inferior vena cava
40-60% of umbilical venous blood bypasses the liver, which allows a significant portion of well-oxygenated blood to enter the heart directly
It plays a crucial role in fetal circulation.
What are the main characteristics of fetal lungs?
Decreased blood flow, thick muscular layer, high pulmonary vascular resistance
These characteristics differ significantly from postnatal lung physiology.
When does surfactant begin to be present in the fetus?
By 20 weeks gestation
Surfactant is critical for lung function after birth.
What is hypoxemia?
Low oxygen in the blood
It can lead to various complications in the fetus.
What is the difference between hypoxemia and hypoxia?
Hypoxemia refers to low oxygen in the blood, while hypoxia refers to low oxygen levels in the tissue
Both conditions are critical to monitor in fetal health.
What is acidosis?
Increased concentration of H+ in the tissue
It can arise from respiratory or metabolic causes.
What causes respiratory acidosis in a fetus?
Increased CO2 from lack of exchange
Can occur rapidly and may lead to significant metabolic acidosis if prolonged.
What is asphyxia during labor primarily due to?
Ongoing progressive hypoxia
This leads to cellular metabolic changes and can cause significant harm.
True or False: Neonatal depression is synonymous with perinatal asphyxia.
False
Neonatal depression can have multiple causes beyond asphyxia.
What factors influence fetal to neonatal adaptation?
Maternal placental blood flow, blood pressure, maternal oxygenation
These factors are critical for a successful transition to extrauterine life.
What does the APGAR score assess?
Activity, Pulse, Grimace, Appearance, Respiration
It provides a quick assessment of the newborn’s health and response to resuscitation.
What are the phases of physiologic adaptation in a newborn?
First period of reactivity, sleep phase, second period of reactivity
These phases describe the newborn’s initial responses after birth.
What is the role of surfactant in the lungs?
Stabilizes the alveoli and prevents collapse
Surfactant is essential for maintaining proper lung function.
What happens to pulmonary vascular resistance (PVR) after birth?
It decreases significantly
This is due to lung aeration and increased oxygen levels.
What is the function of the ductus arteriosus?
Shunts blood from the right ventricle to the aorta
Equal in size to the aorta. Blood flows R to L because of high pulmonary vascular resistance and low placental resistance
It is a key fetal shunt that closes after birth.
Fill in the blank: The umbilical vein carries _______ blood from the placenta to the fetus.
oxygenated
This is crucial for fetal oxygen delivery.
What is a common cause of neonatal respiratory distress?
Surfactant deficiency
This can lead to conditions such as Respiratory Distress Syndrome (RDS).
What indicates a need for gavage feeding in newborns?
Choking/cyanosis with feeds
This may suggest esophageal atresia or other feeding difficulties.
What is the normal range for a newborn’s hematocrit?
45 – 65 gm/dl
This range is important for assessing newborn health.
What is the significance of the transition period in a newborn’s life?
Most dramatic changes occur in the first few minutes of life
This period is critical for establishing normal physiological functions.
What is the normal respiratory rate for a newborn?
40-60 bpm
This rate can vary with activity and state.
What is acrocyanosis?
Normal peripheral cyanosis in newborns
It is often seen in the first few hours after birth.
