Beckman MF Phys Flashcards
Earliest changes in maternal phys
Cardiovascular
Heart is displaced during pregnancy:
Up and left. From diaphragmatic elevation by displacement of abdominal viscera by enlarging uterus
Primary CV change
Increased CO by 30-50%
Why does systemic vascular resistance decrease
Smooth muscle relaxing effect of progesterone, increased vasodilatory substances, AV shunting to the uteroplacental circ
_____% of the CO goes through uterus at term, increasing the risk of
20%; post partum hemorrhage
How much does CO increase during labor
40%
Why does CO increase significantly after delivery?
Venous return is no longer blocked by the gravid uterus impinging on the vena cava
Increased S2 split with inspiration, distended neck veins, and low grade systolic ejection murmurs characterize:
Normal CV physical exam findings during pregnancy (note: diastolic murmurs are NOT normal)
most notable changes to coagulation system
increased fibrinogen conc.
Primary anatomic change of renal system
enlargement and dilation of the kidneys and urinary collecting system
RPF changes and RAAS
at term, can be up to 75% greater than normal. RAAS system also increases (substrates)
changes in lung function
20% decrease in RV and FRC, 5% decrease in Total Lung Volume
40% increase in TV and minute ventilation = Respiratory alkalosis (but also inc. inspiratory capacity)
(maternal respiratory rate will be unchanged)
acid-base changes due to increase in minute ventilation
Progesterone =
increased central chemo-R sensitivity to CO2 = increased ventilation and decreased arterial pCO2 = RESPIRATORY ALKALOSIS =
compensation by increased renal excretion of bicarb
changes to maternal hematoligc system (anatomic)
increase in plasma volume, red cell volume, and coagulation factors
Does supplemental iron use prevent IDA in mother or fetus?
Prevent in the mother. (Fe is actively transported to the fetus, so fetal hemoglobin (Hgb) are maintained regardless of maternal stores)
Pregnant women should receive how much iron supplementation?
60 mg daily (in a women who is not naturally anemic). Recommend 27mg of this comes from iron supplement (present in most prenatal vitamins)
Changes in clotting factors
Fibrinogen (factor 1) increases as well as VII, VIII, IX, X
Prothrombin (II) and V and XII do not change
Protein C and S (inhibitors of coag) decrease
functional pulm changes
- increase in total oxygen carrying capacity
- increased Hg affinity for oxygen in maternal lungs
- increased CO2 gradient btwn fetus and mother in the placenta
risk for thromboembolism in pregnancy
pregnancy = hypercoagulable state = 2x risk of thromboembolism
change to creatinine and BUN during normal pregnancy
decrease. Note that creatinine clearance actually increases
Imagining of renal system during preg would show:
Normal dilation of the collection system resembling hydronephrosis
which of the following changes in size: stomach, intestines, liver, biliary tract, portal veins
portal veins (increased blood flow)
2 mot notable GI pregnancy-related physical findings
Gingival disease and hemorrhoids
hCG effect on T4
in 1st trimester, hCG’s thyrotropin-like activity produces transient rise in free t4. placental hCG decreases after 1st tri = normalization of free t4
