SlideShare a Scribd company logo
1 of 14
Download to read offline
The fetal circulation
Fetal Circulation
The fetal circulation is the circulatory
system of a human fetus, often
encompassing the entire fetoplacental
circulation which includes the umbilical
cord and the blood vessels within
the placenta that carry fetal blood.
The foetal circulation works differently
from that of born humans, mainly because
the lungs are not in use:
the foetus obtains oxygen and nutrients
from the mother through the placenta and
the umbilical cord.
Placental Role
The core concept behind foetal circulation is that
foetal hemoglobin has a higher affinity for oxygen
than does adult hemoglobin, which allows a diffusion
of oxygen from the mother's circulatory system to the
foetus.
The circulatory system of the mother is not directly
connected to that of the fetus, so the placenta
functions as the respiratory center for the fetus as
well as a site of filtration for plasma nutrients and
wastes.
Water, glucose, amino acids, vitamins, and inorganic
salts freely diffuse across the placenta along with
oxygen.
The umbilical arteries carry blood to the
placenta, and the blood permeates the sponge-like
material there. Oxygen then diffuses from the
placenta to the chorionic villus, an alveolus-like
structure, where it is then carried to the umbilical
Connection between the right and left
atria via the foramen ovale
Connection between the truncus
pulmonalis and the aorta via the ductus
arteriosus
The ductus venosus shunts most of the
left umbilical vein blood flow directly to the
inferior vena cava. Thus, it allows
oxygenated blood from the placenta to
bypass the liver.
The hypogastric arteries enter the
umbilical cord and then known as the
The fetal circulation
Circuit
Blood from the placenta as carried to the foetus by
the umbilical vein. Less than a third of this enters
the foetal ductus venosus and is carried to
the inferior venacava, while the rest enters
the liver proper from the inferior border of the liver.
The branch of the umbilical vein that supplies the
right lobe of the liver first joins with the portal vein.
The blood then moves to the right atrium of
the heart. In the foetus, there is an opening
between the right and left atrium (the foramen
ovale), and most of the blood flows through this
hole directly into the left atrium from the right
atrium, thus bypassing pulmonary circulation.
The continuation of this blood flow is into the left
ventricle, and from there it is pumped through
the aorta into the body.
Some of the blood moves from the aorta
through the internal iliac arteries to the ,
umbilical arteries and re-enters the
placenta, where carbon dioxide and other
waste products from the fetus are taken up
and enter the maternal circulation.
Some of the blood entering the right atrium
does not pass directly to the left
atrium through the foramen ovale, but enters
the right ventricle and is pumped into
the pulmonary artery. In the foetus, there is a
special connection between the pulmonary
artery and the aorta, called the ductus
arteriosus, which directs most of this blood
away from the lungs (which aren't being used
for respiration at this point as the fetus is
suspended in amniotic fluid).
The fetal circulation
The fetal circulation
Blood Pressure
It is the fetal heart and not the mother's heart that
builds up the fetal blood pressure to drive its blood
through the fetal circulation.
Intracardiac pressure remains identical between the
right and left ventricles of the human fetus.
The blood pressure in the fetal aorta is
approximately 30 mmHg at 20 weeks of gestation,
and increases to ca 45 mmHg at 40 weeks of
gestation.The fetal pulse pressure is ca 20 mmHg
at 20 weeks of gestation, increasing to ca 30 mmHg
at 40 weeks of gestation.
The blood pressure decreases when passing through
the placenta. In the arteria umbilicalis, it is ca 50
mmHg. It falls to 30 mmHg in the capillaries in the
villi. Subsequently, the pressure is 20 mm Hg in the
umbilical vein, returning to the heart
Flow
The blood flow through the umbilical cord is
approximately 35 mL/min at 20 weeks, and
240 mL/min at 40 weeks of gestation.
Adapted to the weight of the fetus, this
corresponds to 115 mL/min/kg at 20 weeks
and 64 mL/min/kg at 40 weeks. It corresponds
to 17% of the combined cardiac output of the
fetus at 10 weeks, and 33% at 20 weeks of
gestation.[6]
Endothelin and prostanoids
cause vasoconstriction in placental arteries,
while nitric oxide causes vasodilation. On the
other hand, there is no neural vascular
regulation, and catecholamines have only
little effect.
Changes in the Circulation at Birth
The changes which occur are not due to tying of
the umbilical cord, but rather to establishment
of respiration.
When the infant cries, the lungs expand and
their vascular field is increased; so the blood
which has been passing through the ductus
arteriosus to the aorta now flows through the
pulmonary arteries to the lungs for oxygenation.
Within a short period of from five to twenty
minutes, the ductus arteriosus closes and
eventually becomes a cardiac ligament. In a
very small number of cases the ductus
arteriosus remains patent.
The increased flow of blood to the lungs
reduces the pressure in the right side of the
heart and increases the tension in the left side,
causing the valve-like foramen ovale to
close. If this does not occur, the venous blood
in the right atrium will mix with arterial blood in
the left atrium of the heart.
The part of the umbilical vein lying under the
abdominal wall becomes thrombosed and
occluded soon after the cord is tied and forms
a fibrous cord, the ligamentumteres of the liver.
The ductus venosus becomes the
ligamentum venosum which supports the
attachment of the portal vein to the inferior
vena cava. The hypogastric arteries atrophy
and form a ligament between the bladder and
umbilicus.
The fetal circulation

More Related Content

What's hot (20)

Mechanism of labour
Mechanism of labourMechanism of labour
Mechanism of labour
 
Foetal circulation ppt
Foetal circulation pptFoetal circulation ppt
Foetal circulation ppt
 
The placenta and fetal membranes
The placenta and fetal membranesThe placenta and fetal membranes
The placenta and fetal membranes
 
Fetalcirculation
FetalcirculationFetalcirculation
Fetalcirculation
 
Fetal circulation
Fetal circulationFetal circulation
Fetal circulation
 
Aph Antepartum hemorrhage
Aph Antepartum hemorrhageAph Antepartum hemorrhage
Aph Antepartum hemorrhage
 
Foetal circulation (1)
Foetal circulation (1)Foetal circulation (1)
Foetal circulation (1)
 
Female pelvis
Female pelvisFemale pelvis
Female pelvis
 
FETAL CIRCULATION
FETAL CIRCULATIONFETAL CIRCULATION
FETAL CIRCULATION
 
Physiological changes during pregnancy
Physiological changes during pregnancyPhysiological changes during pregnancy
Physiological changes during pregnancy
 
hyperemesis gravidarum
hyperemesis gravidarumhyperemesis gravidarum
hyperemesis gravidarum
 
Partograph
PartographPartograph
Partograph
 
AMNIOTIC FLUID PPT
AMNIOTIC FLUID PPT AMNIOTIC FLUID PPT
AMNIOTIC FLUID PPT
 
Fetal circulation
Fetal circulation Fetal circulation
Fetal circulation
 
Second stage of labor
Second stage of laborSecond stage of labor
Second stage of labor
 
PHYSIOLOGY OF LACTATION
PHYSIOLOGY OF LACTATIONPHYSIOLOGY OF LACTATION
PHYSIOLOGY OF LACTATION
 
Placenta development
Placenta developmentPlacenta development
Placenta development
 
Physiology of lactation
Physiology of lactationPhysiology of lactation
Physiology of lactation
 
Placenta
Placenta Placenta
Placenta
 
Malposition and malpresentations
Malposition and malpresentationsMalposition and malpresentations
Malposition and malpresentations
 

Similar to The fetal circulation

fetalcirculation-181202080431 (1).pdf
fetalcirculation-181202080431 (1).pdffetalcirculation-181202080431 (1).pdf
fetalcirculation-181202080431 (1).pdfAMOSMELI
 
Fetal circulation by dr.srikanta biswas
Fetal circulation by dr.srikanta biswasFetal circulation by dr.srikanta biswas
Fetal circulation by dr.srikanta biswasSrikanta Biswas
 
Foetairculation
FoetairculationFoetairculation
FoetairculationRavi Kant
 
Fetal circulation.pptx
Fetal circulation.pptxFetal circulation.pptx
Fetal circulation.pptxDeepti Kukreti
 
Blood circulation of fetus
Blood circulation of fetus Blood circulation of fetus
Blood circulation of fetus ssuserc95804
 
Fetal circulation
Fetal circulationFetal circulation
Fetal circulationsetiawan278
 
CMC Fetal Circulation.pptx Dr Biswajit Mukherjee
CMC Fetal Circulation.pptx Dr Biswajit MukherjeeCMC Fetal Circulation.pptx Dr Biswajit Mukherjee
CMC Fetal Circulation.pptx Dr Biswajit Mukherjeebmukherjee47
 
fetal circulation.pptx
fetal circulation.pptxfetal circulation.pptx
fetal circulation.pptxsalmanmustaan1
 
fetal circulation.pptx
fetal circulation.pptxfetal circulation.pptx
fetal circulation.pptxMj201
 
THE BLOOD CIRCULATION IN FETUS
THE BLOOD CIRCULATION IN FETUSTHE BLOOD CIRCULATION IN FETUS
THE BLOOD CIRCULATION IN FETUSDr. Hament Sharma
 
Fetal circulation
Fetal circulationFetal circulation
Fetal circulationKhush Bakht
 
fetalcirculation-200727100552.pdf
fetalcirculation-200727100552.pdffetalcirculation-200727100552.pdf
fetalcirculation-200727100552.pdfHarshitaCool1
 
Fetal circulation- panneh
Fetal circulation- pannehFetal circulation- panneh
Fetal circulation- pannehabdou panneh
 

Similar to The fetal circulation (20)

1-fetal circulation
 1-fetal circulation 1-fetal circulation
1-fetal circulation
 
fetalcirculation-181202080431 (1).pdf
fetalcirculation-181202080431 (1).pdffetalcirculation-181202080431 (1).pdf
fetalcirculation-181202080431 (1).pdf
 
Fetal circulation by dr.srikanta biswas
Fetal circulation by dr.srikanta biswasFetal circulation by dr.srikanta biswas
Fetal circulation by dr.srikanta biswas
 
Foetairculation
FoetairculationFoetairculation
Foetairculation
 
Fetal circulation.pptx
Fetal circulation.pptxFetal circulation.pptx
Fetal circulation.pptx
 
Fetalcirculation
FetalcirculationFetalcirculation
Fetalcirculation
 
fetal circulation.pptx
fetal circulation.pptxfetal circulation.pptx
fetal circulation.pptx
 
Fetal Circulation .pptx
Fetal Circulation .pptxFetal Circulation .pptx
Fetal Circulation .pptx
 
Blood circulation of fetus
Blood circulation of fetus Blood circulation of fetus
Blood circulation of fetus
 
Fetal circulation
Fetal circulationFetal circulation
Fetal circulation
 
CMC Fetal Circulation.pptx Dr Biswajit Mukherjee
CMC Fetal Circulation.pptx Dr Biswajit MukherjeeCMC Fetal Circulation.pptx Dr Biswajit Mukherjee
CMC Fetal Circulation.pptx Dr Biswajit Mukherjee
 
FOETAL CIRCULATION.pdf
FOETAL CIRCULATION.pdfFOETAL CIRCULATION.pdf
FOETAL CIRCULATION.pdf
 
FOETAL CIRCULATION.pdf
FOETAL CIRCULATION.pdfFOETAL CIRCULATION.pdf
FOETAL CIRCULATION.pdf
 
fetal circulation.pptx
fetal circulation.pptxfetal circulation.pptx
fetal circulation.pptx
 
fetal circulation.pptx
fetal circulation.pptxfetal circulation.pptx
fetal circulation.pptx
 
Foetal circulation
Foetal circulationFoetal circulation
Foetal circulation
 
THE BLOOD CIRCULATION IN FETUS
THE BLOOD CIRCULATION IN FETUSTHE BLOOD CIRCULATION IN FETUS
THE BLOOD CIRCULATION IN FETUS
 
Fetal circulation
Fetal circulationFetal circulation
Fetal circulation
 
fetalcirculation-200727100552.pdf
fetalcirculation-200727100552.pdffetalcirculation-200727100552.pdf
fetalcirculation-200727100552.pdf
 
Fetal circulation- panneh
Fetal circulation- pannehFetal circulation- panneh
Fetal circulation- panneh
 

The fetal circulation

  • 2. Fetal Circulation The fetal circulation is the circulatory system of a human fetus, often encompassing the entire fetoplacental circulation which includes the umbilical cord and the blood vessels within the placenta that carry fetal blood. The foetal circulation works differently from that of born humans, mainly because the lungs are not in use: the foetus obtains oxygen and nutrients from the mother through the placenta and the umbilical cord.
  • 3. Placental Role The core concept behind foetal circulation is that foetal hemoglobin has a higher affinity for oxygen than does adult hemoglobin, which allows a diffusion of oxygen from the mother's circulatory system to the foetus. The circulatory system of the mother is not directly connected to that of the fetus, so the placenta functions as the respiratory center for the fetus as well as a site of filtration for plasma nutrients and wastes. Water, glucose, amino acids, vitamins, and inorganic salts freely diffuse across the placenta along with oxygen. The umbilical arteries carry blood to the placenta, and the blood permeates the sponge-like material there. Oxygen then diffuses from the placenta to the chorionic villus, an alveolus-like structure, where it is then carried to the umbilical
  • 4. Connection between the right and left atria via the foramen ovale Connection between the truncus pulmonalis and the aorta via the ductus arteriosus The ductus venosus shunts most of the left umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver. The hypogastric arteries enter the umbilical cord and then known as the
  • 6. Circuit Blood from the placenta as carried to the foetus by the umbilical vein. Less than a third of this enters the foetal ductus venosus and is carried to the inferior venacava, while the rest enters the liver proper from the inferior border of the liver. The branch of the umbilical vein that supplies the right lobe of the liver first joins with the portal vein. The blood then moves to the right atrium of the heart. In the foetus, there is an opening between the right and left atrium (the foramen ovale), and most of the blood flows through this hole directly into the left atrium from the right atrium, thus bypassing pulmonary circulation. The continuation of this blood flow is into the left ventricle, and from there it is pumped through the aorta into the body.
  • 7. Some of the blood moves from the aorta through the internal iliac arteries to the , umbilical arteries and re-enters the placenta, where carbon dioxide and other waste products from the fetus are taken up and enter the maternal circulation. Some of the blood entering the right atrium does not pass directly to the left atrium through the foramen ovale, but enters the right ventricle and is pumped into the pulmonary artery. In the foetus, there is a special connection between the pulmonary artery and the aorta, called the ductus arteriosus, which directs most of this blood away from the lungs (which aren't being used for respiration at this point as the fetus is suspended in amniotic fluid).
  • 10. Blood Pressure It is the fetal heart and not the mother's heart that builds up the fetal blood pressure to drive its blood through the fetal circulation. Intracardiac pressure remains identical between the right and left ventricles of the human fetus. The blood pressure in the fetal aorta is approximately 30 mmHg at 20 weeks of gestation, and increases to ca 45 mmHg at 40 weeks of gestation.The fetal pulse pressure is ca 20 mmHg at 20 weeks of gestation, increasing to ca 30 mmHg at 40 weeks of gestation. The blood pressure decreases when passing through the placenta. In the arteria umbilicalis, it is ca 50 mmHg. It falls to 30 mmHg in the capillaries in the villi. Subsequently, the pressure is 20 mm Hg in the umbilical vein, returning to the heart
  • 11. Flow The blood flow through the umbilical cord is approximately 35 mL/min at 20 weeks, and 240 mL/min at 40 weeks of gestation. Adapted to the weight of the fetus, this corresponds to 115 mL/min/kg at 20 weeks and 64 mL/min/kg at 40 weeks. It corresponds to 17% of the combined cardiac output of the fetus at 10 weeks, and 33% at 20 weeks of gestation.[6] Endothelin and prostanoids cause vasoconstriction in placental arteries, while nitric oxide causes vasodilation. On the other hand, there is no neural vascular regulation, and catecholamines have only little effect.
  • 12. Changes in the Circulation at Birth The changes which occur are not due to tying of the umbilical cord, but rather to establishment of respiration. When the infant cries, the lungs expand and their vascular field is increased; so the blood which has been passing through the ductus arteriosus to the aorta now flows through the pulmonary arteries to the lungs for oxygenation. Within a short period of from five to twenty minutes, the ductus arteriosus closes and eventually becomes a cardiac ligament. In a very small number of cases the ductus arteriosus remains patent.
  • 13. The increased flow of blood to the lungs reduces the pressure in the right side of the heart and increases the tension in the left side, causing the valve-like foramen ovale to close. If this does not occur, the venous blood in the right atrium will mix with arterial blood in the left atrium of the heart. The part of the umbilical vein lying under the abdominal wall becomes thrombosed and occluded soon after the cord is tied and forms a fibrous cord, the ligamentumteres of the liver. The ductus venosus becomes the ligamentum venosum which supports the attachment of the portal vein to the inferior vena cava. The hypogastric arteries atrophy and form a ligament between the bladder and umbilicus.