OB: Maternal Physiology Flashcards
Increased ___ demands
[Maternal Physiology]
Metabolic
H______ changes
[Maternal Physiology]
Hormonal
A__ Changes
[Maternal Physiology]
Anatomic
Begin as early as the ___ week and extend into the postpartum period
[Maternal Physiology-VC]
4th___
_____ Left Ventricular Hypertrophy by 20 weeks, with a __% increase in mass at term
[Maternal Physiology-CV]
Eccentric
50%
___of parturients exhibit tricuspid and pulmonic regurgitation; ____ mitral regurg
[Maternal Physiology-CV]
94%, 27%
Heart Rate is increased________% at term
[Maternal Physiology-CV]
15-30
Tachyarrhythmias more common in ___ trimester
[Maternal Physiology-CV]
third
Cardiac Output increases approximately ___%
[Maternal Physiology-CV]
40
Initially due to increased ________
[Maternal Physiology-CV]
Heart rate
By the second trimester, increased ____more so than increased _______
[Maternal Physiology-CV]
stroke volume, heart rate
Increased stroke volume correlates with increasing ___ levels
[Maternal Physiology-CV]
estrogen
At term approximately ___% of CO perfuses the uterus
[Maternal Physiology-CV]
10-20
During labor uterine ____ autotransfuse volume to circulation
[Maternal Physiology-CV]
contractions
After delivery CO can increase up to ____% due to
____
____
[Maternal Physiology-CV]
80
Relief of aortocaval compressionn
Contracted uterus
CO gradually returns to normal at approximately 2 weeks postpartum as ___ and ___ normalize
[Maternal Physiology-CV]
HR and SV
Venous return _____ increases due to increased volume
[Maternal Physiology-CV]
Preload
Increased susceptibility to____ heart rate changes
[Maternal Physiology-CV]
baroreflex-mediated
Third heart sound can be heard in most women by 20 weeks due to early closure of the ____________ valve
[Maternal Physiology-CV]
Mitral
A ___ heart sound can be heard in 16% of pregnant women, but usually disappears at term.
[Maternal Physiology-CV]
Fourth
__________ murmurs are common, __________ murmurs are pathologic
[Maternal Physiology-CV]
Systolic, diastolic
Compression of the ___ ___ by the gravid uterus
More severe in polyhydramnios or multiple gestation pregnancies
Decreased venous return
Significantly decreased SV and ultimately ___________________
Then ___________________________________
May result in loss of consciousness
May be immediate or take up to 10 minutes to be symptomatic
Abdominal aorta may also be compressed
Upper body BP remains normal
Lower body (including uterus) BP decreases
[Aortocaval Compression]
vena cava
cardiac output
uterine/fetal oxygenation decrease
More severe in ____ or multiple gestation pregnancies
[Aortocaval Compression]
polyhydramnios
____ venous return
[Aortocaval Compression]
Decreased
Significantly decreased SV and ultimately ____
[Aortocaval Compression]
Cardiac output
Then decreases uterine ___ and fetal ____
[Aortocaval Compression]
perfusion and oxygenation
May result in loss of c_____
[Aortocaval Compression]
Consciousness
May be immediate or take up to ___ minutes to be symptomatic
[Aortocaval Compression]
10
A___ ___may also be compressed
[Aortocaval Compression]
abdominal aorta
Upper body___remains normal
[Aortocaval Compression]
BP
Lower body (including uterus) BP ___
[Aortocaval Compression]
decreases
Relieved by tilting to the ___ < laying on either side
[Aortocaval Compression]
left
Left uterine displacement increases intervillous blood flow an average of __% and increases fetal oxygenation __%
[Aortocaval Compression]
20, 40
Left uterine displacement can be achieved by tilting the operating table ___ degrees or by placing a ___ high wedge under the parturient’s right hip and back.
[Aortocaval Compression]
15, 15 cm
A small percentage of women may benefit from ___ uterine displacement more than___, but this is a small minority.
[Aortocaval Compression]
right, left
Needs a ___-degree or a ____ cm wedge under the right hip and back
[Left Uterine Displacement]
15, 15
Especially large uterus (___ or ___) may need more lift
[Left Uterine Displacement]
polyhydraminos or multiple
Degree of tilt is usually ___
[Left Uterine Displacement]
underestimated
Because MAP decreases slightly, the increase in uteroplacental blood flow is dependent on (1) a substantial decrease in ___ ___ ___, (2) increased c___ ___, and (3) increased i___ ___
[Vascular Changes and Regulation]
uterine vascular resistance, cardiac output, intravascular volume
Vascular remodeling of arteries in the uterus is believed to include increases in both vessel ___ > ___
(Dust off the cobwebs and think Physics laws!)
[Vascular Changes and Regulation]
diameter, length
Changes in vascular reactivity include vasodilatory response mediated at ___ and ___ smooth muscle levels
[Vascular Changes and Regulation]
endothelial and vascular
Growth of the placenta creates a [low/high] -resistance vascular pathway by eliminating ___ microcirculation and creating an ___ space
[Vascular Changes and Regulation]
low, intramyometrial, intervillous
SVR ___ as much as 21%
[Vasculature Changes]
decreases
Venous capacitance loses tone, allowing for pooling of the ___ ___
[Vascular Changes and Regulation]
blood volume
Aside from pathology, systolic blood pressure changes [little/more], diastolic blood pressure may decrease by up to ___ mmHg
[Vasculature Changes]
little, 15
Generalized reduction on response to ___ and ___ vasoconstrictors
[Decreased Response to Vasoconstrictors]
endogenous and exogenous
(lecture notes say exogenous and exogenous)
Angiotensin II, En___, Thromboxane, Epinephrine, Norepinephrine, Phenylephrine, S___, Thromboxane, and A___ ___
[Decreased Response to Vasoconstrictors]
Endothelin, Serotonin, Arginine Vasopressin
Concentrations of Angiotensin II increase __-___x more than non-pregnant
[Response to Catecholamines]
2-3
BUT the sensitivity to Angiotensin II is [decreased/increased]
[Response to Catecholamines]
decreased
The ___ circulation is even less responsive to Angiotensin II than the ___ circulation (contributes to the redistribution of cardiac output, increase of uterine blood flow
[Response to Catecholamines]
uterine, systemic
This ___ is decreased in patients with PIH
[Response to Catecholamines]
refractoriness
Sensitivity to Epinephrine, Norepinephrine, and Phenylephrine is also [increased/decreased] in pregnancy
[Response to Catecholamines]
decreased
BUT the uterine circulation is ___ sensitive to these than the systemic circulation
[Response to Catecholamines]
MORE
THEREFORE, during massive hemorrhage/trauma/stresses resulting in large ___ release, it is unlikely that ___perfusion will be preferentially preserved above essential ___perfusion
[Response to Catecholamines]
catecholamine, uteroplacental, maternal
Clearance of vasopressin at near/term is 3-4 times ___ than before pregnancy.
[Response to Catecholamines]
greater
Vasopressinase levels increase by a factor of ___between early and term pregnancy.
[Response to Catecholamines]
50
Vasopressinase is made by the ___
[Response to Catecholamines]
placenta
More dependent on ___-___ ___ for maintenance of blood pressure than non-pregnant
[Renin]
renin-angiotensin system