Physiology in Pregnancy Flashcards
What general changes occur during pregnancy?
- Mechanical
- Metabolism
- Fatigue – particularly early pregnancy
- Heartburn/reflux
- Oedema
- Breasts
- Thyroid
- General state of immunosuppression
- Weight gain
What changes occur to the breasts during pregnancy?
- Increased size and vascularity – warm tense and tender
- Increased pigmentation of the areola and nipple
- Secondary areola appears
What appears on the areolas?
Montgomery tubercles
When can colostrum be expressed?
From the end of the 3rd month
When do significant changes occur in the CVS?
Early in the first trimester
What changes does the CVS undergo?
- Increased circulating volume
- Systemic vascular resistance falls
- Increased blood flow
- Increased cardiac output
- Increased stroke volume
- Increased heart rate
- Increased O2 consumption
What happens to cardiac output in the supine position?
25% reduction
When does maximal systemic vascular resistance decrease occur?
20-32 weeks
By how much does cardiac output increase?
40%
Why do women experiencing pain during labour?
Increasing catecholamines
What intrapartum CS changes occur?
Auto transfusion of contractions
What happens to cardiac output during labour and post-delivery?
- Increases by 10% in labour
- Increases 80% in 1st hour post-delivery
- Continues to fall over the 1st 24 hours
What happens to blood volume post delivery?
Decreases by 10% 3 days post-delivery
What happens to blood pressure post delivery?
Falls then increases again days 3-7
What happens to SVR post delivery?
Increases over the first 2 weeks to 30% above delivery levels
What happens to heart rate post delivery?
Returns to pre-pregnancy levels over 2 weeks
When do CVS return to normal?
3 months post-partum usually
When does BP reach pre-pregnancy levels?
Usually by 6 weeks post-partum
What doesn’t change in the respiratory system with pregnancy?
PEFR and FEV1
What happens to blood gases with pregnancy?
- Decrease in PCO2
- Increase in PO2
What respiratory changes take place during pregnancy?
- Increase in oxygen demand
- Increase in minute ventilation
- Increased respiratory rate
- Increased tidal volume
- Decreased functional residual capacity
By how much does minute volume increase?
40-50%
By how much does oxygen demand increase?
20%
What may be present in the urine of pregnant women?
Glucose and microscopic haematuria
