Normal Pregnancy (Santillan) Flashcards
Which of these is a physiologic change associated with an increase in estrogen?
A. increased synthesis of natural anticoagulants
B. decreased liver synthesis of fibrinogen
C. decreased laxity of ligaments
D. pospartum surge of estrogen leads to lactation
E. growth of breast ducts
E. Estrogen increases the synthesis of procoagulants (Factors 1, 7, 8, 9, 10) as well as fibrinogen, binding proteins for corticosteroids and sex steroids. It also increases laxity in the ligaments and, its postpartum withdrawal is what leads to lactation.
Which of these is a physiologic change associated with an increase in progesterone?
A. hyperventilation, leading to mild respiratory alkalosis
B. onset of lactation
C. increase in the growth of breast ducts
D. smooth muscle contraction throughout the body
E. increased excretion of potassium
A.
B and C are not correct because progesterone withdrawal postpartum is what leads to lactation, and it causes hypertrophy of breast alveolae, not ducts. D and E are incorrect because progesterone is smooth muscle relaxant and leads to a conservation of potassium.
week of gestation when the placenta begins to take over primary production of progesterone from the corpus luteum
8 weeks
blood flow in pregnancy increases to all of these organs EXCEPT: A. kidneys B. breast C. liver D. skin E. heart
C. Blood flow to the liver (and the brain) undergoes no change in pregnancy.
Name 3 changes in blood pressure that tend to occur during pregnancy.
- By 28 weeks there is generally a drop in DSB by 10 mm Hg
- There is a 10 mm Hg difference in both SBP and DBP between standing and sitting/LL decubitus
- Slightly increased pulse pressure in the 3rd trimester
BP nadir is generally observed between what weeks of pregnancy?
24-32 weeks gestation
Any early decrease in systemic vascular resistance (SVR) with the nadir at 14-24 weeks gestation may be the trigger for an increase in HR, SV and CO. what causes this drop in SVR?
prostaglandins, progesterone, placental shunt, and NO
increases and decreases throughout the pregnant body are noted as they pertain to antepartum hemodynamics, but where are no changes noted to occur?
pulmonary capillary wedge pressure (measures left atrial pressure), central venous pressure (measures right atrial pressure/right ventricular preload) and mean arterial blood pressure do not change
within 10-15 minutes postpartum, there is a 60-80% increase in CO. name 3 reasons for this.
- autotransfusion of utero-placental blood to systemic circulation
- sudden decreased obstruction of the vena cava by the uterus
- rapid mobilization of extravascular fluid
True or false: while cardiac output returns to prelabor values within an hour after delivery, left ventricular dimensions take several months to decrease.
True. Left atrial dimensions are increased pospartum as well, and take about 10 days to decrease.
which of the following remain unchanged in regards to maternal pulmonary physiology?
A. Tidal volume and functional residual capacity
B. Vital capacity and respiratory rate
C. Total lung capacity and vital capacity
D. Functional residual capacity and tidal volume
E. Respiratory rate and total lung capacity
B. FRC and TLC both decrease by 20%, and tidal volume increases (~40%) to maintain vital capacity.
what changes are noted in arterial blood gases during pregnancy?
PCO2 and HCO3 decrease due to hyperventilation, PO2 and pH increase
what effect does the mild respiratory alkalosis of pregnancy have on Hgb offloading to the fetus?
alkalosis causes a leftward shift of the O2 dissociation curve, which means higher affinity of Hgb for O2 and decreased offloading of O2 to the fetus
why is right-sided dilation in the urinary collecting system often more dilated than the left during pregnancy?
because of the dextrorotation of the uterus and “protection” of the sigmoid colon
what 2 factors in the renal anatomic changes of pregnancy lead to physicologic stress incontinence?
shortening of the ureters and increased intraurethral closing pressure
Which of the following renal physiologic changes occur during pregnancy?
A. Decreased GFR
B. Decreased CO when mother is in the left lateral recumbent position
C. Decreased serum creatinine
D. Increased urea concentrations
E. Decreased vasodilation post glomerulus
C. During pregnancy, increased plasma concentrations lead to increased CO (particularly in the LL recumbent position), increased vasodilation of vessels both pre and post golmerulus and increased GFR
during pregnancy, decreased levels of this vasodilator released by the heart acts to promote Na+ and fluid reabsorption and maintain increased blood volume
atrial natriuretic factor (ANF)
progesterone in pregnancy works to increase Na+ filtration and excretion by directly opposing the effects of what hormone?
aldosterone
Which of the following exhibits decreased excretion during pregnancy?
A. Potassium B. Glucose C. Uric acid D. Amino acids E. Sodium
A. Progesterone inhibits aldosterone, which would normally function to increase Na+ reabsorption and K+ excretion.
All of the rest show increased excretion by various mechanisms:
Glucose - impaired reabsorption in LoH and collecting duct
Uric acid - increased GFR and reduced tubular reabsorption
Amino acids - unknown mechanism for selective loss of aa
Na+ - progesterone inhibition of aldosterone
This layer of the uterus is an important controller of coagulation, because progesterone increases tissue factor and plasminogen activating (tPA) inhibitor at its level; it also plays the primary role in meidating puerperal hemostasis (poastpartum bleeding)
uterine decidual layer
clotting factors that are increased during pregnancy
factors 1, 7, 8, 9, 10
increased synthesis of procoagulants, increased activation of platelets, increased proteins S, resistance to protein C and venous stasis are all reasons why pregnancy is considered a ____ state
hypercoaguable
estrogen increases the production of ____ through the ER beta receptor, leading to skin changes
melanin
True or false: linea nigra and cholasma are both caused by an increase in melanocyte stimulating hormone production from the adrenal cortex.
False. Both conditions result from an increase in MSH, but this comes from the placenta, not the adrenal cortex.