Fetal Circulation Flashcards
What are the adaptations that must happen at birth?
Cardiovascular adaptation
Pulmonary adaptation
Thermal adaptation
What special features does the fetal cardiovascular system have?
umbilical vein
ductus venosus
foramen ovale
ductus arteriosus
umbilical arteries
What does the umbilical vein do?
Carries oxygenated blood from placenta
What does the ductus venosus do?
What does the foramen ovale do?
What does ductus arteriosus do?
What does the umbilical arteries do?
What is the blood haemoglobin level in the fetus?
20.7 g/dl
What is the blood volume in the fetus?
80-100 ml/kg
When does the ductus arteriosus close?
Within the first few days of birth
What are the adaptations of extrauterine life?
Depends on the interplay between cardiovascular and respiratory system. Initiated within 60 seconds but may not be fully completed for a few week as the separation of the neonate from the placenta results in cessation of blood flow which collapses the umbilical vein and arteries.
What happens to the ductus venosus and the hypogastric arteries after birth?
They will eventually fibrose to become supporting ligaments.
What benefits does delayed cord clamping have?
In term of iron status as well as a more gentle adaptation to extrauterine life
Fetal Breathing Movements
FBMs are episodic and irregular, interspersed with periods of apnea (suspension of breathing)
When are FBMs detectable by ultrasound?
Around 10-11 weeks gestation