Changes in pregnancy - cardiovascular and respiratory system Flashcards
how much does the heart volume increase during pregnancy
12%
When does the plasma volume increase (/40)
34/40
What week does the plasma volume reach its max
32-34/40
Percentage that plasma volume increase by
50% above non-pregnant values
Why is higher circulating volume of blood required in pregnancy
To provide extra blood for placental perfusion + to counterbalance the effects of increased arterial and venous capacity
How much does the heart rate increase by
10-20% - multiple pregnancy = up to 40%
What week does the heart rate increase by
32/40 -
How is the increased cardiac output balanced
by reduced peripheral resistance, due to progesterone acting on the smooth muscle of arterial walls
What are the changes to blood pressure
Decrease in systolic, greater decrease in diastolic
In labour, what changes occur to cardiac output
Increases t/f slight increase in BP
What factors can affect BP
Age and Parity
where does the majority of the increased blood flow go to
Uterus and 80% goes to placenta
How much is the blood flow to kidneys increased by
30-50%
Why is there increased blood flow to the skin
Thermoregulation
How much does plasma volume increase by
40-50%
How much does RBC increase by
20-30%
What does increased plasma volume lead to
a drop in Hb - up to 10%
What does WHO define anaemia as
<110g/L during pregnancy and <100g/L post pregnancy
How much does WCC increase by
8%
How does the heart move when pregnant
Shifts upwards and to the left
What changes occur to the arteries
Dramatic systemic and pulmonary vasodilation to increase blood flow
What changes happen to the veins
Vasodilatation and impeded venous return in lower extremities, facilitated by increased progesterone
What happens to stroke volume
Increased stroke volume bc of increased circulating volume
What is stroke volume
The volume of blood expelled from the ventricle during a contraction (heartbeat)
