Chapter 7: Physiologic Adaptations To Pregnancy Flashcards
Anatomical and physiologic changes of the uterus during pregnancy include
- Uterine growth
- Contractility
- Uterine Blood Flow
By 12 weeks gestation, the fundus of the uterus can be found where?
Can be palpate above the symphysis pubis.
At 16 weeks, the fundus of the uterus extends where?
Reaches midway between the symphysis pubis and the umbilicus.
At 20 weeks, the fundus of the uterus can be found where?
At the umbilicus.
The fundus of the uterus reaches its highest level where and when?
At 36 weeks gestation, it reaches the highest level at the xiphoid process.
Lightening
- When the fetal head descends into the pelvic cavity and the uterus sinks to a lower level by 40 weeks gestation.
- This descent of the fetal head reduces pressure on the diaphragm and makes reaching easier.
How does contractions of the uterus change during pregnancy?
-Braxton Hicks Contractions occur
How does blood flow to the uterus change during pregnancy?
As the uterus enlarges, an increase in the size and number of blood vessels expands blood flow dramatically
Anatomical and physiologic changes of the cervix during pregnancy include
- Water content and vascularity increases
- Hyperemia
- Chadwick Sign
- Goodell Sign
- Mucus plug
What causes hyperemia (congestion with blood) of the cervix during pregnancy?
Increasing levels of estrogen.
Leads to Chadwick sign.
Chadwick sign
Bluish purple discoloration of the cervix, vagina, and labia during pregnancy as a result of increased vascular congestion.
Earliest sign of pregnancy.
Goodell Sign
Softening of the cervix during pregnancy.
Mucus Plug
Plug in the cervical canal that blocks the ascent of bacteria from the vagina into the uterus during pregnancy to help protect the fetus and uterine membranes from infection.
Anatomical and physiologic changes of the respiratory system during pregnancy include
- Oxygen consumption
- Hormonal factors such as progesterone and estrogen
- Physical effects of the enlarging uterus
How does oxygen consumption change during pregnancy?
-Rises by 20%
How does progesterone cause respiratory changes during pregnancy?
- Along with prostaglandins, help decrease airway resistance by up to 50% by relaxing the smooth muscle in the respiratory tract.
- Increase sensitivity of the respiratory center in the medulla to CO2, thus stimulating the increase in minute ventilation.
How does estrogen cause respiratory changes during pregnancy?
- Causes increased vascularity of mucous membranes of the upper respiratory tract
- This leads to edema and hyperemia developed within the nose, pharynx, larynx and trachea.
- This congestion may cause nasal and sinus stuffiness, nosebleed and deepening of the voice.
- May also cause fullness in the ears.
How does the physical effects of the enlarging uterus cause respiratory changes during pregnancy?
- Complaints of SOB (enlarging uterus lifts the diaphragm)
- Increasing size of the uterus interferes with blood return from lower extremities.
- Ribs flare, the substernal angle widens and transverse diameter of the chest expands.
- Breathing become thoracic rather than abdominal -> dyspnea.
Anatomical and physiologic changes of the cardiovascular system during pregnancy include changes in
- Heart size and position
- Heart sounds
- Blood volume
- Plasma volume
- Red blood cell volume
- Cardiac output
- Blood pressure
- Systemic vascular resistance
- Supine hypotension
- Blood flow
- Blood components
Braxton Hicks
Irregular, painless contractions occur throughout pregnancy, although many expectant mothers do not notice them until the third trimester.
Aka false labor.
Hegar sign
Softening of the lower uterine segment that allows it to be easily compressed at 6 to 8 weeks of pregnancy.
Ballottement
Movement after a sudden tap on the cervix during a vaginal examination that causes the fetus to rise in the amniotic fluid and then rebound to its original position.
Gravida
Refers to a woman who is or has been pregnant, regardless of the length of pregnancy. # of pregnancies.
Para
Refers to the number of pregnancies that have ended at 20+ weeks, regardless of whether the infant was born alive or stillborn.
TPAL
T: term pregnancies delivered (37+ weeks)
P: preterm pregnancies delivered(20 weeks to 30 weeks + 6 days)
A: Abortion
L: Number of living children
For multifetal pregnancies, what should you use for gravida, para and TPAL?
Use # of infants not pregnancies!!
Nagele’s Rule
- Used to establish the estimated date of delivery (EDD).
- This method involves subtracting 3 months from the date the last normal menstrual period began, adding 7 days and then correcting the year.
EDB or EDC
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