Maternal Physiology Flashcards
During pregnancy, cardiac output increases by ___ [%].
30-50%
During pregnancy, maximum cardiac output is reached ___ [age of gestation]
Between 20 and 24 weeks’ gestation and maintained until delivery
The increase in cardiac output is first due to an increase in ___ and is then maintained by an increase in ___ as the ___ decreases to near prepregnancy levels by the end of the third trimester
Stroke volume
Heart rate
Stroke volume
Systemic vascular resistance decreases during pregnancy, resulting in a fall in arterial blood pressure. This decrease is most likely due to elevated ___ [hormone], leading to smooth muscle relaxation.
Progesterone
There is a decrease in systolic blood pressure of ___ [mmHg] and in diastolic blood pressure of ___ [mmHg] that nadirs at week ___ [age of gestation]
5-10 mm Hg
10-15 mm Hg
24
There is an increase of 30-40% in tidal volume during pregnancy despite the fact that the total lung capacity is [1: decreased / increased] by 5% due to the elevation of the diaphragm. This increase in tidal volume [2: decreases / increases] the expiratory reserve volume by about 20%.
Decreased total lung capacity
Decreased expiratory reserve volume
PaCO2 decreases to approximately 30 mm Hg by ___ weeks’ gestation from 40 mm Hg during prepregnancy.
20 weeks’
Nausea and vomiting occur in more than ___ % of pregnancies
70%
Nausea and vomiting have been attributed to the elevation in ___, ___, and ___. They may also be due to ___ and can be treated with frequent snacking.
Estrogen
Progesterone
hCG
Hypoglycemia
The nausea and vomiting typically resolve by ___ weeks’ gestation
14-16 weeks’
A severe form of morning sickness associated with weight loss (>/= 5% of prepregnancy weight) and ketosis
Hyperemesis gravidarum
During pregnancy, the stomach has [1: reduced / prolonged] gastric emptying times and the gastroesophageal sphincter has [2: decreased / increased] tone. The large bowel also has [3: decreased / increased] motility.
Prolonged gastric emptying times Decreased esophageal tone Decreased motility (leading to increased water absorption and constipation)
The glomerular filtration rate increases by ___ % early in pregnancy and is maintained until delivery. As a result of increased GFR, blood urea nitrogen and creatinine decrease by about ___ %.
50%, 25%
Although the plasma volume increases by (1) % in pregnancy, the RBC volume increases by only (2) %, which leads to a decrease in the (3), or dilutional anemia.
50%
20-30%
Hematocrit
The WBC count increases during pregnancy to a mean of 10.5 million/mL with a range of ___ million.
6-16 million
During labor, stress may cause the WBC count to rise to over ___ million/mL.
20 million/mL
Changes in clotting and bleeding times in pregnancy
No change
A drop in the platelet count below ___ million/mL over a short time is not normal and should be investigated promptly
100 million/mL
In pregnancy, there are elevations in the levels of fibrinogen and factors:
VII to X
Pregnancy is a hyperestrogenic state. The increased estrogen is produced primarily by the ___.
Placenta (with the ovaries contributing to a lesser degree)