Maternal Physiology pt1 (Exam2) Flashcards
A term gestation is how many weeks?
- 37-40 weeks
- 3 trimesters
below 37 weeks is considered preterm
Parturient refers to what?
one who is pregnant/in labor
Gravida refers to what?
Number of pregnancies (not babies)
Para refers to what?
number of births >20 weeks
(including still born deliveries at >20weeks)
What is G0P0?
Nulligravida/Nulliparous
- No pregnancies
- No births
What would G1P0 refer to?
Primigravida/nulliparous
- pregnant but not given birth yet
could also have had miscarriage <20 weeks
What would G3P2 refer to?
Multigravida/ Multiparous
- 3 pregnancies (2 births/1 miscarriage)
- 2 births
What is the minimum expected weight gain during pregnancy? What are the components that account for this weight gain?
12 kg (~26 lbs) minimum weight gain:
- Uterus = 1 kg
- Amniotic Fluid = 1kg
- Blood volume increase = 2kg
- Fetal/Placental Weight = 4kg
- New Fat/Protein stores = 4kg
.
Describe the impact BMI has on total weight gain and rate of weight gain during pregnancy?
How much does total blood volume increase during pregnancy? What are some common symptoms exhibited secondary to this change?
30 - 35% increase
Increased blood volume is responsible for bloating and fluid retention (swelling)
When does the increase in total blood volume of the typical pregnant woman occur?
8 - 32 weeks (Majority of increase by 24 weeks)
Blood volume increases with pregnancy are a result of an increases in which specific blood volumes? What is a hematologic consequence of this change?
Plasma volume and RBC volume increase
plasma volume increases more than RBC volume.
Dilutional anemia (usually not significant)
Why does blood volume increase during pregnancy?
To counteract delivery blood loss
What is the typical expected blood loss with a vaginal delivery and for a C-section?
- Vaginal: ~500 mL
- C-section: ~800 mL
Approximately when does maternal blood volume return to normal post-delivery?
typically back to prepregnancy levels within 6 weeks postpartum
Compare the blood volume of a pregnant patient and a non-pregnant patient in mL/kg.
Non-pregnant female = ~65mL/kg
Pregnant = ~85-90 mL/kg
CO will typically increase by ___% by term.
~40%
In regards to hemodynamics, by 6 weeks there will be an increase in maternal _____ ____ and by 8 - 10 weeks there will be an increase in _____ _____.
6 weeks: ↑ Heart Rate
8-10 weeks: ↑ Stroke Volume
What is the mechanism for increased Stroke Volume in the pregnant patient?
↑ Plasma Renin ⇒ ↑aldosterone ⇒ ↑Na⁺ reabsorption ⇒ ↑water retention ⇒ ↑ Plasma volume ⇒ ↑ Preload ⇒ ↑ SV & ↑CO
How much does uterine blood flow increase during pregancy?
10-20x increase in UBF
- Baseline = ~50 mL/min
- Term = ~700 mL/min
What is the cause of the pregnancy symptoms of warm skin, flushing, and itching?
3-4x increase in skin blood flow
What changes in SVR occur in pregnancy? Why?
- 20% lower than pre-pregnant values due to massive maternal vasodilation
What hormones are responsible for maternal vasodilation?
“PREP”
- Progesterone
- Relaxin
- Estrogen
- Prostacyclin
Pregnancy is a ____ flow, _____ resistance state.
High flow : low resistance
- maternal vasodilation
-
low resistance placental circulation
-uterine vascular bed has low resistance secondary to massive vasodilation (increasing placental flow) - decreased renal vasculature resistance