Lecture 40 - Maternal Adaptations to Pregnancy

Question 1

By about 20-24 weeks of pregnancy, maternal cardiac output (CO) increases from about ___L/min to _____L/min.. Initially, this increase is due to an increase in _____ _____, but later is a result of increased _____ _____.

Answer 1

5L/min

7L/min

Stroke volume (SV)

Heart Rate (keep in mind at this point SV returns to normal)

Question 2

How does multiple pregnancy (twins, triplets, etc) affect maternal increase in body water and blood volume during pregnancy?

Answer 2

More fetuses –> greater increase

Question 3

Systolic BP and Diastolic BP both _____ in pregnancy, but which is affect more?

Answer 3

Decrease

Diastolic decreases more

Question 4

During pregnancy the heart shifts upward and to the _____ (which side?). Most patients will also have a splitting of the ______ heart sound, especially on ______ (inspiration or expiration?).

With the increase in blood volume and cardiac output, what other sounds might you expect to hear?

Answer 4

Left

2nd

Inspiration

You would expect Systolic flow murmurs (Diastolic murmurs are abnormal!) and development of 3rd heart sound due to rapid diastolic filling.

Question 5

The Poseiro effect describes a transient _______ in the fetal heart rate during Uterine contraction due to compression of maternal vasculature (particularly the _____) and resultant decreased blood flow to the placenta.

Answer 5

Deceleration

Aorta

Question 6

In pregnancy, though there is an increase in the production of most proteins by the liver, there is a decrease in the production of ______.

Combined with increased venous pressure, what effect might this have on edema?

Answer 6

Albumin

Decreased albumin decreases the oncotic pressure in the veins - coupled with increased venous pressure, fluid will tend to move OUT of the veins, causing edema.

Question 7

Regional blood flow to certain areas of the body increase transiently in pregnancy, but it remains elevated in some areas. These include the Skin, the Kidneys, the Breast, and most significantly the ______ (increases from about 100mL/min to 1700mL/min).

Answer 7

Uterus

Question 8

Physiologic anemia of pregnancy arises bc blood _____ increases to a greater degree than _____ cell volume.

How might this help to Decrease the amount of lost O2 carrying capacity per unit volume of blood loss? (Protective effect for post-partum hemorrhage and is a modality used before surgeries.)

Answer 8

Plasma

Red cell volume

If there is more plasma per unit vol of blood, fewer RBCs will be lost per unit volume –> maintains more RBCs in circulation –> maintains O2 carrying capacity.

Question 9

In pregnancy, there is margination of ______ in the bone marrow, which leads to an increase in serum levels.

Answer 9

WBCs (particularly granulocytes)

Question 10

Pregnant and post-partum mothers have higher risk of clotting bc of Venous ______ (from mass effect of enlarged uterus) AND increased production of ______ factors.

Answer 10

Venous stasis

Clotting factors

Question 11

In pregnancy there is an increase in ______ volume and inspiratory _______.

There is a slight increase in total lung capacity and in ______ ventilation as well, which leads to a slight respiratory ______ –> What might be decreased to compensate for this?

Answer 11

Tidal volume

Inspiratory capacity

Minute ventilation

Respiratory Alkalosis

Decreased HCO3-

Question 12

Normal pCO2 for pregnant women is between ____-____, which is low compared to normal. If it gets into the range of what’s normal for nonpregnant women, pathology needs to be ruled out.

Answer 12

25-30mmHg

Question 13

Bc renal blood flow and GFR increase, ______ clearance also increases in pregnancy. Keep in mind this mean ______ levels will be low compared to non-pregnant normal values. Like with pCO2, if levels rise to non-pregnant normal, something may be pathologically wrong.

Answer 13

Creatinine

Creatinine

Question 14

_______ causes a smooth muscle tone decrease, so in terms of GI issues, this means pregnant women are at higher risk for _____. Similarly, this decrease in smooth muscle tone will decease GI motility. –> What effect might this have on fluid reabsorption and quality of the stool?

Answer 14

Progesterone

Reflux

This allows for greater fluid reabsorption –> may lead to stool impaction/constipation.

Question 15

Postpartum hair loss can be a result of fewer follicles entering the ______ phase during pregnancy, which is thought to be due to Estrogen, and then more entering this phase postpartum.

Answer 15

Telogen (Remember that anagen is the growing phase.)

Question 16

About 80% of fetal skeleton development occurs in the ______ trimester. It should make sense then that maternal Ca++ absorption and resorption increases. Thus, pregnant women should be supplemented with _____mg Ca++/day.

Answer 16

Third trimester

1200mg Ca++/day

Question 17

In pregnancy, the uterus grows from about 70g to 1100g. Hypertrophy of which layer is responsible for this?

Answer 17

Myometrium

Question 18

In pregnant women, ______ (hormone) increases insulin secretion and _______ (hormone) increases ______ storage while decreasing Liver glucose.

Answer 18

Progesterone

Estrogen

Question 19

While thyroid function increases in pregnancy, why do levels of free T3 and T4 remain normal?

Answer 19

There is an equivalent increase in Thyroid binding globulin (TBG).