APP Module (GTown) - Pregnancy (Hrs 1 and 2) Flashcards
How long is a full gestation term?
40 weeks, which includes two weeks from LNMP to conception
Why do we date from a patient’s LNMP?
Because date of conception is questionable usually
Why is gestation split into different trimesters?
Because these mark important developmental milestones and come with differing physiology
What is considered pre-term?
Pregnancy before 37 weeks.
What is considered an early and full term pregnancy?
37 to 39 weeks for early term, 39 to 41 weeks for full term
What is considered post-term?
More than 42 weeks
What is gravidity?
The state of being pregnant or how many pregnancies a woman has had
What is parity?
The number of total outcomes of pregnancy
What secretes beta-hcg?
placenta
What does hcg usually maintain?
corpus luteum
What does the corpus luteum secrete?
progesterone
When does the corpus luteum involute?
2nd/3rd trimester
What hormone is critical for early pregnancy?
progesterone
What are the three ways you can diagnose and detect an early pregnancy?
1) beta-hcg levels in serum or urine
2) ultrasound @ around 5 weeks
3) fetal cardiac activity at 6-8 weeks
By how much does plasma volume change in pregnancy?
Increases by ~50%
What are sequela of an increase in plasma volume?
- systolic murmur
- decreased blood viscosity
By how much does RBC volume change in pregnancy?
20-30% increase
The smaller increase in RBC volume as compared to plasma volume results in what?
physiologic dilutional anemia
Why is dilutional anemia not a real anemia?
Because there is an increase in RBCs overall
How much does CO change in pregnancy?
increases 30-50%
What results from an increase in CO?
increase in blood volume, decrease in afterload, uterine blood flow, and increase in HR by late pregnancy
What happens to systemic vascular resistance in pregnancy?
SVR falls in first two trimesters of pregnancy
Why is it thought that SVR falls in pregnancy?
decreased responsiveness to vasoconstrictive hormones
What drops because of a decrease in SVR?
blood pressure (systolic by more than diastolic)