PAL COLLEGE OF NURSING & MEDICAL SCIENCE,
HALDWANI
Microteaching Plan
On
Fetal circulation
Submitted to Submitted by
Mrs Dayabati Soyam Priyanka Joshi
Associate Professor M.Sc Nursing 1st yr
PCNMS PCNMS
SUBMITTED ON- 9/11/2021
STUDENT PROFILE
Name Priyanka Joshi
Title of the course M.Sc Nursing
Class 1st yr
Number of student in the group 10
Topic Fetal circulation
Date and time 26 /11/2021 &
Duration 15min
Venue M.sc nursing 1st yr class
Method of teaching Lecture cum discussion
List of teaching aids PPT , leaflet , White board
Name of the evaluator Mr. Manoj Kumar Jangir
OBJECTIVES
GENERAL OBJECTIVES
At the end of the presentation students will be able to know about fetal circulation and changes of fetal circulation at birth.
SPECIFIC OBJECTIVE
Class will be able -
To introduce about the fetal circulation.
To discuss about the meaning of fetal circulation.
To explain the components of fetal circulation.
To explain the fetal circulation.
To enlist the vessels in umbilical cord.
To explain the circulatory changes after birth.
S.N Specific Content Teaching A.V. Evaluation
. objectives learning Aids
aids
1- To introduced Introduction L PPT What do you
about the fetal The fetal circulation is markedly different from the adult circulation. In the fetus, gas E understand
circulation. exchange does not occur in the lungs but in the placenta. The placenta must therefore receive C by
deoxygenated blood from the fetal systemic organs and return its oxygen rich venous drainage T introduction?
to the fetal systemic arterial circulation. U
2- To discuss R
about the Meaning E What you
meaning of According to Myles The placenta is the source of oxygenation, nutrition and elimination of mean by fetal
fetal waste for the fetus. There are several temporary structures in addition to the placenta and the C circulation?
circulation. umbilical cord that enable the fetal circulation. U
3- M
To explain Leafl
about the
Components of fetal circulation What do you
ets
component of D understand
The ductus venosus- by
fetal I
Which connact with the umblicical vein to the inferior vena cava. componenent
circulation. S
C s of fetal
The foramen ovale circulation?
which is the opening between the right and left atria. U
S
The ductus arteriosis S
which leads to from the bifurcation of the pulmonary artery to the descending aorta. I
O
What do you
The hypo gastric arties N
understand
which branch off from the internal iliac arties and become the umbilical cord. by blood
4 vessels in
To enlist the Blood Vessels In Foetus fetal
vessels in fetus. The blood vessels responsible for foetal circulation are: circulation?
1. Umblical Vein.
2. Umblical Artery.
1. Umblical Vein: PPT
The blood pressure inside the umbilical vein is approximately 20 mmHg. L
It carries the oxygenated blood from the placenta to the growing fetus. E
C
T
2. Umblical Artery: U
They surround the urinary bladder and then carry all the de-oxygenated blood out of the fetus. R
Supplies de-oxygenated blood from the fetus to the placenta. It is a paired artery that is found E
in the pelvic and abdominal region of the fetus which extends into the umblical cord.
C
U
M
D
I
S
C
U
S
S
I
To discuss the O
N
fetal Foetal Circulation: What do you
circulation. understand
The umbilical vein carrying the oxygenated blood (80% saturated) from the placenta, by fetal
circulation ?
enters the fetus at the umbilicus and runs along the free margin of the falciform
ligament of the liver. In the liver, it gives off branches to the left lobe of the liver and
receives the deoxygenated blood from the portal vein.
PPT
The greater portion of the oxygenated blood, mixed with some portal venous blood,
short circuits the liver through the ductus venosus to enter the inferior vena cava and L
thence to right atrium of the heart. The O2 content of this mixed blood is thus reduced. E
5- C
Although both the ductus venosus and hepatic portal/fetal trunk bloods enter the right T
U
atrium
R
through the IVC, there is little mixing. E
The terminal part of the IVC receives blood from the right hepatic vein. C
In the right atrium, most of the well oxygenated (75%) ductus venosus blood is U
M
preferentially directed into the foramen ovale by the valve of the inferior vena cava and
crista dividens and passes into the left atrium.
D
Here it is mixed with small amount of venous blood returning from the lungs through I
S
the pulmonary veins.
C
This left atrial blood is passed on through the mitral opening into the left ventricle. U
S
Remaining lesser amount of blood (25%), after reaching the right atrium via the S
superior and inferior vena cava (carrying the venous blood from the cephalic and I
O
caudal parts of the fetus respectively) passes through the tricuspid opening into the N
right ventricle.
During ventricular systole, the left ventricular blood is pumped into the ascending and
arch of aorta and distributed by their branches to the heart, head, neck, brain and arms. PPT
The right ventricular blood with low oxygen content is discharged into the pulmonary
trunk. Since the resistance in the pulmonary arteries during fetal life is very high, the
main portion of the blood passes directly through the ductus arteriosus into the
descending aorta bypassing the lungs where it mixes with the blood from the proximal L
E
aorta. 70% of the cardiac output (60% from right and 10% from left ventricle) is C
T
carried by the ductus arteriosus to the descending aorta. U
R
About 40% of the combined output goes to the placenta through the umbilical arteries.
E
To discuss the The deoxygenated blood leaves the body by way of two umbilical arteries to reach the
circulatory C
changes after placenta where it is oxygenated and gets ready for recirculation. What do you
U
birth. M understand
The mean cardiac output is comparatively high in fetus and is estimated to be 350
by
mL/kg/min. circulatory
D changes after
I birth?
The Circulatory Changes After Birth:
The Placenta is replaced by the Lungs as the organ of respiratory exchange. The lungs and S White
pulmonary vessels expand thereby significantly lowering the resistance to blood flow. C board
Subsequently the pressure in the pulmonary artery and the right side of the heart is decreased. U
6- The pressure of the left side of the heart increases. The increasing pressure of blood in the left S
side of the heart decreases the vascular resistance of the lungs, therefore, the blood now enters S
the lungs as a respiratory exchange. I
O
N
Closure of the Ductus Venosus:
1. Functional closure occurs within minutes of birth.
2. Structural closure occurs within 3 to 7 days.
3. After it closes, the remnant is known as ligamentum venosum.
4. Closure of ductus venosus is caused by strong contraction of muscle wall of ductus venosus,
but the cause of this contraction is not revealed yet.
Closure of the Ductus Arteriosus: L
1. Closure of ductus arteriosus is by smooth muscle contraction. E
2. It is further replaced by fibrous tissue, called ligamentum arteriosum. C
3. At birth, opposite direction of blood flow from aorta to pulmonary artery supplies more T
oxyginated blood than before. U
4. This contraction of smooth muscle occurs becuase of the increase in availability of oxygen. R
5. The degree of smooth muscle contraction is highly dependant on more availability of E
oxygen.
C
Closure of the Foramen Ovale: U
1. Before birth the foramen ovale allows most of the oxygenated blood entering the right M
atrium from the Inferior Vena Cava to pass into the left atrium.
2. Closes at birth due to decreased flow from placenta and Inferior Vena Cava to hold open
foramen. D
3. More importantly because of increased pulmonary blood flow and pulmonary venous return I
to left heart causing the pressure in the left atrium to be higher than in the right atrium. S
4. The increased left atrial pressure then closes the foramen ovale against the septum C
secundum (between right and left atrium). U
5. The output from the right ventricle now flows entirely into the pulmonary circulation. S
S
I
Conclusion
O
Fetal blood circulation between the fetal liver and the ductal insertion into the aorta, the fetal
N
circulation consists of a series of shunts that achieve sequential partitioning of bloodstreams
with different nutritional content. Active partitioning of nutrient-rich umbilical venous blood
by the ductus venosus affects global downstream distribution of nutrients. Passive shunting
through the foramen ovale and aortic isthmus predominantly affects nutrient partitioning
between the heart, brain and lungs. In contrast to the venous side of the circulation, arterial
distribution is primarily redundant due to differential effects of afterload on foramen ovale and
aortic isthmus shunting. Deviations from the physiological states can result in venous and
arterial redistribution. Heart and brain sparing act synergistically with redistribution to
augment organ flow. In contrast, liver sparing is invoked when excessive venous redistribution
jeopardizes hepatic supply. Beyond the ductus arteriosus, adjustments of organ flows may be
less dependent on redistribution, relying on -flow reserve.
7- Research articles
Verburg B , Jaddoe V, Wladimiroff V, Fetal hemodynamic adaptive changes related to
intrauterine growth: the Generation Study The method of This study was embedded in a
population-based, prospective cohort study starting in early fetal life. Fetal growth
characteristics and fetal circulation variables were assessed with ultrasound and Doppler
examinations in 1215 healthy women. Result of the study was the fetal circulation was
examined in relation to estimated fetal weight. Higher placental resistance indices were
strongly associated with decreased fetal growth. Cerebral resistance showed a gradual decline
with reduced fetal growth. Cardiac output, peak systolic velocity of the outflow tracts, and
cardiac compliance showed a gradual reduction with diminished fetal growth, whereas
intraventricular pressure gradually increased.Conclusions of the study was decreased fetal
growth is associated with adaptive fetal cardiovascular changes. Cardiac remodeling and
cardiac output changes are consistent with a gradual increase in afterload and compromised
arterial compliance in conditions of decreased fetal growth. These changes have already begun
to occur before the stage of clinically apparent fetal growth restriction and may contribute to
the increased risk of cardiovascular disease in later life.
References
Verburg B , Jaddoe V, Wladimiroff V, Fetal hemodynamic adaptive changes related to
intrauterine growth: the Generation Study Circulation. 2008 Feb 5;117(5):649-59.doi:
10.1161/CIRCULATIONAHA.107.709717. Epub 2008 Jan 22
Dutta DC , textbook of obstetric. 9th Ed .published by Jaypee publication . P no-59.
Journal of obstetrics and gynecological nursing.
Bhasker Nima. Midwifery and Obstetrical Nursing. Ed- 2nd (2016), Hardiya publication.
Pp.33.
