Introduction To Obstetrics

Question 1

What are the 4 categories of maternal physiological changes?

Answer 1

1. Physical growth
2. Circulatory system
3. Respiratory system
4. Metabolism and endocrine

Question 2

The uterus grows from ___ g in size to __kg in size during pregnancy

Answer 2

2g - 1kg

Question 3

The uterus can hold ___ml of volume normally and up to _____ml of volume during pregnancy

Answer 3

10ml
5000ml

Question 4

There is significant weight gain that pregnant women undergo. Where do these weight gains occur and approximately how much is gained for each

Answer 4

• blood volume, ECF, ICF : 3kg
• uterus : 1.4kg
• placenta : 1kg
• Fetal growth : about 3kg
• breast tissue : 1kg
• Fat and Protein: 12 kg

Question 5

During pregnancy the mother undergoes circulatory system changes. What part of these changes cause an “Increase”?

Answer 5

Increase in
- blood volume
- venous distension
- RBC
- WBC
- clotting factors

Question 6

Why does blood volume increase in pregnant women?

Answer 6

This is to accommodate the circulatory needs of the mother and fetus. It allows for perfusion of maternal organs and in preparation of blood loss during delivery

Question 7

What percentage does blood volume increase during pregnancy?

Answer 7

40-50%

Question 8

How much does venous distention increase during pregnancy and what complication risk does it run?

Answer 8

• 150%
• development of DVT and PE; especially under conditions like prolonged bed rest

Question 9

What percentage does RBC count increase during pregnancy?

Answer 9

33%

Question 10

Normal WBC count is _____ and increases to ______ during pregnancy

Answer 10

4,400 to 12,000 cells/ul

Question 11

Blood pressure drops during which trimester of pregnancy and then normalizes back?

Answer 11

In the second trimester and normalizes in 3rd

Question 12

Why does the heart size grow during pregnancy. And by how much does the heart grow?

Answer 12

• the heart grows to boost cardiac output by 40% to meet the increased metabolic demands
• the heart grows 10 - 15%

Question 13

How much does the heart rate increase during pregnancy?

Answer 13

15 - 20 BPM

Question 14

Why can ectopic beats and SVT appear during pregnancy?

Answer 14

It can be due to the increased CO and HR

Question 15

Why might left axsis deviation occur during pregnancy?

Answer 15

Caused by the pressure exerted on the diaphragm by the growing uterus

Question 16

How much of the bodies oxygen demand increases during pregnancy?

Answer 16

Increases by 20% and half of this demand is by the uterus

Question 17

What respiratory adjustments are made to the nasal track during pregnancy and why?

Answer 17

• nasal stuffiness and increased mucous production
• due to enhanced vascularity in the mucous membranes and nasal passages which can lead to frequent nose bleeds

Question 18

How does progesterone play a role in respiratory changes during pregnancy?

Answer 18

• It lowers the CO2 level threshold in the medulla
• leads to bronchodilation and reduced airway resistance
• increases Tidal volume and Minute ventilation by 50%

Question 19

Pregnant women experience a decrease in partial pressure CO2 and Bicarbonate levels. This leads to what?

Answer 19

Respiratory alkalosis

Question 20

What does the hormone relaxin do?

Answer 20

Leads to the relaxation of ligament usually around the pelvic area to facilitate childbirth and accommodate the expanding uterus

Question 21

What changes occur in carbohydrate demand during pregnancy?

Answer 21

The demand for carbs increase to supply glucose to the fetus

Question 22

How does pregnancy affect maternal insulin sensitivity?

Answer 22

Insulin sensitivity decreases due to pregnancy hormones, this is to ensure adequate glucose supply to the fetus and preventing maternal hypoglycaemia

Question 23

How can changes in carbohydrate metabolism during pregnancy lead to gestational diabetes?

Answer 23

The decrease in insulin sensitivity during pregnancy can lead to gestation diabetes in women predisposed to glucose regulation issues