Maternal Adaptations to Pregnancy

Question 1

___ ___ ___:Aka supine hypotensive syndrome: the enlarging uterus compresses the __ __ __ (impeding venous return to the heart), and aorta.

Results in a fall of __ __

Symptoms: nausea, lightheadedness, often sweaty. May also see effect on fetus due to decrease in utero-placental perfusion.

Tx: improved by turning onto the side.

Answer 1

AORTO-CAVAL COMPRESSION :

Aka supine hypotensive syndrome: the enlarging uterus compresses the inferior vena cava (impeding venous return to the heart), and aorta.

Results in a fall of cardiac output

Symptoms: nausea, lightheadedness, often sweaty. May also see effect on fetus due to decrease in utero-placental perfusion.

Tx: improved by turning onto the side.

Question 2

Hematological/Cardio Changes

1-2 liter __ overall

Plasma volume __ 30-50%, RBCs __ by 20%, ___ platelets by 10%

HR increases, SV increases → CO increases 50% over gestation.

Answer 2

Hematological/Cardio Changes

1-2 liter increase overall

Plasma volume increases 30-50%, RBCs increase by 20%, decreased platelets by 10%

HR increases, SV increases → CO increases 50% over gestation.

Question 3

BP drops in pregnancy but will start to normalize towards term as blood and body water increases for compensation

Mechanism: ___ causes a fall in systemic vascular resistance. Placenta acts as a low pressure circuit, resulting in lower of blood pressure in the first and mostly second trimester.

Answer 3

BP drops in pregnancy but will start to normalize towards term as blood and body water increases for compensation

Mechanism: progesterone causes a fall in systemic vascular resistance. Placenta acts as a low pressure circuit, resulting in lower of blood pressure in the first and mostly second trimester.

Question 4

how does GFR change in pregnancy?

Answer 4

increase in GFR and renal blood flow

Renal collecting system dilation (progesterone affect and obstruction from uterus) → leads to urinary stasis with risk of UTI.

Note: urinalysis of a pregnant woman will often have leukocytes from vaginal contamination

Note: a normal serum creatinine in a pregnant woman SHOULD BE LOW

Question 5

Respiration Adaptations in Pregnancy

Diaphragm __

• Increased __ __ (volume of air inspired and expired with each breath), increased __ ventilation (volume inspired or expired in 1 minute), __ O2 consumption.
• Upper respiratory capillary engorgement.
• __ functional residual capacity: volume remaining in lungs after passive expiration → __ expiratory reserve and residual volumes.
• Increase in __ or elevated diaphragm may result in __ of __ → subjective

Answer 5

Respiration Adaptations in Pregnancy

Diaphragm rises

• Increased tidal volume (volume of air inspired and expired with each breath), increased minute ventilation (volume inspired or expired in 1 minute), increased O2 consumption.
• Upper respiratory capillary engorgement.
• Decreased functional residual capacity: volume remaining in lungs after passive expiration → decreased expiratory reserve and residual volumes.
• Increase in progesterone or elevated diaphragm may result in dyspnea of pregnancy → subjective

Question 6

in pregnancy, a relative hyperventilation leads to a respiratory ___

Answer 6

Changes to Blood Gases

Decrease in PaCO2, increase in PaO2 (relative hyperventilation)

Relative respiratory alkalosis (mild increase in PH to 7.4-7.45

Compensated by increased renal excretion of bicarbonate

A “normal” pH of 7.35 would be considered pathologic!

Question 7

why does pregnancy lead to a hypercoaguloable state?

Answer 7

The coagulation balance favours increased coagulation→ pregnancy is in a hyper-coaguable state

Increase in venous stasis and vascular damage = increased risk of deep vein thrombosis and pulmonary embolism in the pregnant patient.

*elevated D-dimer test in pregnancy is NOT diagnostic of DVT