Pregnancy Flashcards
What causes dyspnea in pregnancy?
5% Dec in total lung capacity (TLC), due to baby pushing up diaphragm.
In pregnancy there is a ___ in minute ventilation in order to maintain normal ____.
INCREASE in min ventilation, to maintain normal respiration rate.
Hyperventilation in pregnancy is causes by ____, not ___
increase in TV, NOT respiratory rate (RR)
Which pulmonary value decreases in pregnancy?
TLC dec by 5% bc diaphragm is pushed up by baby.
Which pulmonary value decreases in pregnancy?
Oxygen consumption and TV (min vent inc)
min ventilation and TV increases in preg because ____
respiratory centers are more sensitive to CO2.
CO2 levels in pregnancy are ___, but pH is normal due to compensation by _____
- Lower
- Kidney compensated.
Endocrine changes in pregnancy (hint: Estrogen, insulin, progesterone).
- Hyperestrogenic (estrogen from placenta) = hypercoaggulable state (clots)
- diabetogenic (increased blood sugar due to inc insulin resistance)
- Progesterone causes uteruis smooth muscle to relax (prevents expulsion of fetus)
____ causes hypercoagulable state in pregnancy, increasing risk of _____
Hyperestrogenic state = estrogen from placenta
Inc risk of blood clots (think pulmonary embolism)
____ should double every 48 hrs in early pregnancy
hCG levels
What do pregnancy tests detect?
hCG levels in blood/urine, being secreted by placenta. Serum test is more sensative
Function of hCG in early pregnancy
maintains corpus luteum, which produces progesterone essential for maintaining preg.
Source of progesterone in first trimester vs. 2nd/3rd trimester
1st – corpus luteum
2nd/3rd – placenta makes its own progesterone (and estriol), corpus luteum degenerates.
when can ultrasound can be used to detect pregnancy?
4-5 wks
Conception to birth is ____ but we calculate gestational pd from ____
266 days = 38 wk = 9 months
the last period
Normal gestational pd
280 days = 40 wk = 9.5 months. (from last period to birth, NOT conception to birth)
gravidity
number of pregnancies
parity
P = Term - preterm - abortions - living children
Physiologic anemia of pregnancy
- aka dilutional anemia.
- Caused by inc in plasma volume that’s more than inc in RBC volume (result = hematocrit or %BC in blood V dec)
In the first 2 trimesters, what happens to BP and why?
- both systolic and diastolic BP dec. (5-10, 10-15), 2 reasons:
- due to dec in systemic resistance and dec in blood viscosity (more dilute!)
What causes decreased systemic vascular resistance in preg?
- decreased responsiveness to vasoconstrictive hormones
- decreased blood viscosity
How is the uterus “primed” for labor?
- Fetal hormone secretion* stimulates massive estrogen release from placenta.
- Estrogen induces expression of oxytocin and prostoglandin receptors on uterine myometrium.
what initiates labor?
Fetus. fetal oxytocin initiates:
1) cervical dilation
2) uterine prostoglandin secretion.
During parturition, cervical dilation is initiated by ___ and dilation stimulates _____.
- dilation initiated by fetal oxytocin
- stimulates release of maternal oxy from posterior pituitary (Ferguson reflex)
