Pregnancy Flashcards
Below what body fat percentage does ovulation cease?
22%.
Below what body mass is amenorrhoea a risk?
<47 kg.
List 3 features of the changes of maternal physiology.
1) Anticipatory —> precedes foetal growth and demand
2) In excess —> in excess of foetal demand
3) Dynamic —> changes vary through the trimesters
List 3 symptoms that occur due to changes to the renal system during pregnancy.
1) Generalised oedema
2) Increased thirst
3) Decreased urine output
List 3 physiological features that occur due to changes to the renal symptoms.
1) Increased creatinine output
2) Glucosuria
3) Aminoaciduria
List 2 conditions that are at risk due to changes to the renal system during pregnancy.
1) Hydronephrosis (esp. RHS)
2) Pyelonephritis (esp. RHS)
How does total plasma volume change during pregnancy?
Increases, 1-2 L (30-50%).
How does plasma osmolality change during pregnancy?
Decreases, 280 mosmol/kg (NP) —> 270 mosmol/kg (T).
List 2 natriuretic factors during pregnancy.
1) Progesterone
2) Atrial natriuretic peptide
List 4 antinatriuretic factors during pregnancy.
1) Aldosterone
2) Renin
3) Angiotensin
4) Deocycorticosterone
Why is eGFR not a valid measure of kidney function during pregnancy?
1) Creatinine output increases
2) Plasma creatinine decreases
How does kidney size change during pregnancy?
Increases, 20% by term.
List 4 signs that occur due to changes to the cardiovascular system during pregnancy.
1) Decreased blood pressure (early/mid pregnancy)
2) Increased blood pressure (late pregnancy)
3) Altered heart sounds
4) Altered ECG trace
List 2 physiological features that occur due to changes to the cardiovascular system during pregnancy.
1) Increased cardiac output
2) Increased pulmonary flow
List 2 conditions that are at risk due to changes to the cardiovascular system during pregnancy.
1) Dilutional anaemia
2) Thromboembolism
How does cardiac output change during pregnancy?
Increases, 30-50%.
How long postpartum does the risk of thromboembolism persist?
6-8 months.
Which 3 clotting factors increase during pregnancy?
1) VII
2) VIII
3) X
List 7 cardiac anatomical changes that occur during pregnancy.
1) Diaphragm elevates 4 cm
2) Heart displaces superiorly and laterally
3) Apex displaces laterally
4) Heart is more horizontal
5) Increased left atrium size
6) Increased left ventricle size
7) Increased ventricular muscle mass
List 4 ECG abnormalities found during pregnancy.
1) Lead III —> inverted T wave
2) Lead III —> prominent Q wave
3) Lead aVF —> prominent Q wave
4) 15 degree left axis deviation
List 3 lung function test changes that occur due to changes to the respiratory system during pregnancy.
1) Increased tidal volume
2) Increased vital capacity
3) Decreased total lung volume
List 4 respiratory anatomical changes that occur during pregnancy.
1) Diaphragm elevates 4 cm
2) Increased subcostal angle (70 degrees (NP) —> 105 degrees (T))
3) Increased thoracic circumference
4) Decreased chest compliance
How does tidal volume change during pregnancy?
Increases, 450 ml (NP) —> 650 ml (T), 200ml (40%).
Explain why pregnant women experience subjective dyspnoea.
Due to the increased tidal volume, pregnant women take deeper breaths, so they feel as though they are out of breath.
How does total lung volume change during pregnancy?
Decreases, 4200 ml (NP) —> 4000 ml (T), 200 ml.
List 5 lung function tests that are unchanged during pregnancy.
1) Respiratory rate
2) FEV1
3) FVC
4) FEV1/FVC
5) Peak flow
How does PCO2 change during pregnancy?
Decreases, 4.7 kPa (NP) —> 4.0 kPa (T).
Describe how compensated respiratory alkalosis occurs during pregnancy. (6)
1) Progesterone mediated increased CO2 sensitivity of respiratory centre chemoreceptors
2) Increased tidal volume
3) Increased CO2 exhaled
4) Decreased PCO2
5) Respiratory alkalosis
6) Excess HCO3- renally excreted
Describe how respiratory alkalosis enables placental CO2 exchange during pregnancy. (5)
1) Foetal PCO2 —> 5.0 kPa
2) Maternal PCO2 —> 4.0 kPa
3) Foetal PCO2 > maternal PCO2
4) Foetal:maternal CO2 diffusion gradient
5) CO2 diffusion across placenta
How does oxygen consumption change during pregnancy?
Increases, 250 ml/min (NP) —> 300 ml/min (P) (15-20%).