Physiology in Pregnancy- also look at antenatal Flashcards
List some General changes to the body during pregnancy?
- Increased lumbar curvature to compensate for the belly
- Fatigue
- Reflux due to loosening of GI sphincters
- Oedema
- Breast
- Thyroid (iodine used up so thyroid enlarges to compensate)
- General Immunosuppression
- Weight Gain
How does the breast change durine pregnancy?
Increased pigmentation of the areola and nippl
Same Increased size and vascularity – warm tense and tender
Secondary areola appears
Montgomery tubercules appear on the areola
Colostrum like fluid can be expressed from the end of the 3rd month
How does blood volume change during pregnancy?
Up to 50-70% more blood volume while pregnant
How does heart activity change during pregnancy?
SV & HR rise leading to a much higher CO. Most women have Sinus Tachycardia during pregnancy
SVR also drops significantly
Why does CO increase so much during pregnancy?
Because O2 consumption goes way up
How can changing position affect a pregnant woman’s CO?
If they lie supine the foetus presses on the IVC reducing venous return and so reducing CO.
Why is it important to understand how a pregnant woman’s CO decreases in supine position?
Trying to do CPR resuscitation on a pregnant woman is impossible if lying supine, you must move the uterus or lie then tilted.
Also never examine a pregnant woman supine, let them sit up or lie on the side
How does increased CO affect risk of heart problems?
Increased CO means the heart muscle requires more O2. Thus there’s an increased risk of angina or MI
How does blood volume & pressure during labour?
Every contraction pushes blood from uterus into systemic circulation (Autotransfusion).
This increases blood volume and BP so is dangerous, especially in people with existing BP problems or stenotic lesions
How does CO change durine labour?
Increases by 10% during labour and up to 80% in the first hr post-delivery. So they’re still at massive risk after delivery.
When does the CV system return to normal after pregnancy?
Most are back to normal within 3 months
How long does BP take to return to normal?
It falls and icnreases again in the first 3-7 days but returns to pre-preg levels by 6wks
How long before HR returns to normal?
2 wks
How long before CO returns to normal?
incerases by 80% in first hour post delivery then falls back to normal over 24 weeks
How do the lungs change during pregnancy?
40-50% increae in ventilation with RR & TIdal volume increasing. (to compensate for increases O2 demand)
But PEFR FEV1 are unchanged
