Maternal Physiology Flashcards
How does TBW change in pregnancy?
Increase- 6.5 L to 8.5 L
Chronic volume overload
Increase in what blood components lead to increased TBW?
Plasma volume
RBC mass
What happens to serum sodium levels during pregnancy?
Decrease
Water retention > Na retention
What is the lower limit for normal serum Na?
135 mmol
131 in pregnancy- drops 3-4 mmol
ANP/BNP become elevated during pregnancy, can BNP still be used to screen for CHF?
Yes
Increases is much greater in CHF than the normal physiologic response to pregnancy
What accounts for the dilutional anemia seen in pregnancy?
Plasma volume increases more than RBC mass
What is responsible for decreased systemic vascular resistance in pregnancy?
Progesterone
In what position is a pregnant woman’s CO greatest?
Left lateral position
Low birth weight is associated with women who do large amounts of standing work, what is this attributed to?
Decreased CO
Blood flow increases to what organs during pregnancy?
Kidneys
Uterus, breast
Skin
What changes are seen on CXR in a pregnant woman?
Flattened left heart border
Prominent pulmonary vasculature
Heart position more horizontal
Elevation of diaphragm
What changes does pregnancy have on pulmonary gas exchange?
RR no change TV increase Hyperventilation- progesterone PaCO2 decreases PaO2 increases pH increases Bicarb decreases
What does increased TV during pregnancy result in?
Increased O2 uptake
Increased minute ventilation = RR*TV
What happens to forced viral capacity during pregnancy?
Remains unchanged
What happens to ERV during pregnancy?
Decreased
Due to elevated diaphragm
A pregnant woman has a PCO2 of 40, what is this a sign of?
Impending respiratory failure
Should be low due to hyperventilation
What term is used to describe the physiologic urinary tract changes during pregnancy?
Relative hydronephrosis of pregnancy- vasculature, interstitial volume, urinary dead space (dilation of renal pelvis, calyces, ureters)
When does relative hydronephrosis resolve?
Week 6 postpartum
What hormone is responsible for relative hydronephrosis of pregnancy?
Progesterone- SM relaxation
Aside from progesterone what else cause relative hydronephrosis of pregnancy?
Mechanical compression due to enlarging uterus
How can relative hydronephrosis of pregnancy make interpretation of urinary images difficult?
More difficult to evaluate urinary tract obstruction
Ultra sound
Define calculus.
Stone
Relative hydronephrosis increases the risk of what infection?
Pyelonephritis- urinary stasis
What is a normal GFR?
100 mL/min
What measurement approximates GFR?
Creatinine- slight overestimate
What is the lower limit of normal for CRCL?
97 M
88 W
What changes do you expect to see in a pregnant woman’s BUN and Cr?
Both decreased
Result of increased GFR + increased plasma volume
A woman has chronic renal insufficiency, what effect can a pregnancy have on her disease?
1/3 in women may have worsening
What is physiologic anemia of pregnancy?
Hemodilution
Plasma volume>RBC mass
What causes increased risk for intravascular coagulation during pregnancy?
Virchow’s triad
stasis, endothelial damage, changes in clotting factors
What effect does pregnancy have on PT/PTT/thrombin time?
Drop slightly (still normal range)
Where do most DVTS occur? Where does most pyelonephritis occur? (During pregnancy)
DVT- 90% L
Pyelonephritis- 90% R
What is the standard of care for diagnosis DVT?
Doppler US
What is the treatment for DVT during pregnancy?
LMW heparin
Nausea and vomiting of pregnancy complicates 70% of pregnancies. There are many medicines and alternative therapies, what vitamin seems to benefit women?
Vitamin B6
What is hyperemesis gravidarum?
Refractory nausea/vomiting Associated with: Weight loss Dehydration Ketonemia Electrolye imbalances
What is hyperemesis gravidarum associated with?
Increased levels of hCG
Hyperthyroidism
Hyperpigmentation is seen in 90% of pregancies, what hormone is responsible for these changes?
hCG
linea nigra, areolae, nipples, genital skin, axillae, melasma
