Repro 8.2 Maternal problems in pregnancy

Question 1

What systems undergo changes during pregnancy?

Answer 1

• Cardiovascular
• respiratory
• gastrointestinal
• immune system
• Urinary system
• Haemolytic system
• Metabolism

Question 2

What changes occur to the CVS during pregnancy?

Answer 2

• Blood volume increases by up to 50%
• Cardiac output, stroke volume and heart rate all increase
• Blood pressure falls
• vascular resistance decreases

Question 3

Why do changes happen to the CVS system during pregnancy?

Answer 3

• to prepare for partuition

- to provide for the foetus and placenta.

Question 4

What happens to the blood pressure over the course of a pregnancy?

Answer 4

T1 and T2- decreased
T3 normal.

Systolic blood pressure should not change throughout/

Question 5

What causes the increase in blood volume during pregnancy?

Answer 5

Oestrogen and progesterone affect the RAAS system, and reduce water and sodium excretion, therefore blood volume increases.

Question 6

What effects do progesterone and oestrogen have on the CVS during pregnancy?

Answer 6

• increase blood volume (by alterring RAAS and causing retention of sodium and water)
• decrease peripheral resistance by causing systemic vasodilation

Question 7

What should be considered when measuring a pregnant woman’s blood pressure?

Answer 7

You should not measure her BP whilst lying supine becuase the gravid uterus can compress the IVC, reducing blood return to the heart, so the patient will become hypotensive.

Question 8

What is the condition known as when a pregnant woman’s blood pressure is taken lying down?

Answer 8

Supine hypotensive syndrome.

Question 9

What effects does pregnancy have on the urinary system?

Answer 9

• Increased GFR
• Increased creatinine, protein clearance
• relaxation of the collecting systems.

Question 10

Why does GFR increase during pregnancy?

Answer 10

progesterone leads to vasodilation of the afferent arteriole, increasing the amount of blood going to the kidneys and being filtered.

Question 11

What happens to blood levels of urea, creatinine and bicarbonate ions during pregnancy?
Why?

Answer 11

They all decrease.

Urea and creatinine due to increased clearance.

Bicarbonate due to compensation of physiological respiratory alkalosis by increasing excretion of HCO3-

Question 12

Why might you detect glucose in the urine of a pregnant woman?

Answer 12

there is an increased GFR and renal blood flow, but there is a fixed reabsoprtive capacity of the PCT, so only a certain amount of glucose can be reabsorbed.

If this limit gets exceeded, the remaining glucose will be excreted into the urine.

Question 13

Why are pregnant women more prone to UTI’s?

How is this avoided?

Answer 13

• relaxation of the ureters causes stasis of urine, which is an ideal breeding ground for bacteria.
• immune system becomes compromised in the pregnant state.
• Each time a pregnant woman goes for a check up she will have a urine dip stick to test for any UTI’s so they can get treated early.

Question 14

What urinary pathology are pregnant females more likely to encounter?

Answer 14

• UTI
• Pyelonephritis
• Hydronephrosis (due to relaxation of the ureters, and the slow movement of urine)
• AKI (secondary to pyelonephritis)
• renal stones

Question 15

What anatomical changes happen to the respiratory system during pregnancy?

Answer 15

• Displacement of the diaphragm due to the presence of the gravid uterus
• increased AP and transverse diameter of the thoracic cavity

Question 16

What physiological changes happen to the respiratory system during pregnancy?

Answer 16

• increased tidal volume
• increased alveolar ventilation
• increased minute ventilatory volume
• decreased functional residual capacity
• phsyiological hyperventilation

Question 17

What is ‘physiological hyperventilation’ in pregnancy?

What can this cause?

Answer 17

progesterone causes an increased respiratory drive which causes dyspnoea.

This can lead to hyperventilation where too much CO2 is being blown off.
As a result respiratory alkalaemia can develop.
This is compensated for by the kidneys which excrete bicarbonate ions.

Question 18

What is the risk of the kidneys compensating for respiratory alkalosis during pregnancy?

Answer 18

The icnreased excretion of HCO3- ions means there is a reduced HCO3- buffer, so acidosis is more likely to occur during pregnancy.

Question 19

What metabolic changes occur to the mother during the first half of pregnancy?

Answer 19

ANABOLIC PHASE

• increase insulin:anti insulin levels
• increased lipogenesis
• building up stores for the fetus later in the pregnancy

Question 20

What metabolic changes occur in the mother in the last half of pregnancy?

Answer 20

CATABOLIC PHASE

• decreased insulin:anti insulin levels
• lipolysis
• increased blood glucose levels available for the fetus

Question 21

What’s the benefit of increased peripheral insulin resistance during pregnancy?

How does the mother deal with this?

Answer 21

It means less glucose is taken up into the cells, so plasma glucose levels increase, leaving more for the fetus to use.

The mother switches to fatty acids and gluconeogenesis for her fuel.

Question 22

During pregnancy, what happens to blood levels of ketones, free fatty acids, cholesterol and glucose levels in the mother?

Answer 22

• ketones, free fatty acids and cholesterol all increase (the mother i know using this for her fuel)
• Glucose transiently increases following a meal (due to increased insulin resistance) But otherwise it has decreased levels because the fetus is using lots of glucose.

Question 23

Which hormone promotes the metabolic changes that happen during pregnancy?

Answer 23

Human placental lactogen.

oestrogen, progesterone and cortisol also help

Question 24

What are the effects of Human placental lactogen during pregnancy on metabolism?

Answer 24

• helps inhibit glucose uptake
• increases insulin release
• increases free fatty acid levels

Question 25

Why is ketoacidosis associated with pregnancy?

Answer 25

Due to low insulin:anti insulin ratio and increase free fatty acid levels in the blood. Also reduced bicarbonate buffering ability increases risk of acidosis

Question 26

What is gestational diabetes?

Answer 26

A state of carbohydrat3e intolerance which occur in pregnancy and disappears after pregnancy.

Question 27

What risks are associated with gestational diabetes?

Answer 27

- Macrosomic fetus - Stillbirth - congenital defects

Question 28

What happens to thryoid levels in pregnancy?

Answer 28

TBG and T3/4 levels are increased. Free levels of T3 and T4 are the same (due to the increased TBG being able to bind more) TSH can be decreased (negative feedback)

Question 29

What stimulated changes to the thyroid gland in pregnancy?

Answer 29

Human chorionic gonadotrophin directly acts on the thyroid gland, increasing T3/4 production.

Question 30

What anatomical changes happen to the GIT of the mother during pregnancy?

Answer 30

Disposition of the viscera due to the presence of the gravid uterus. This can be an issue eg appendicitis when the pain may be felt higher up, so clinicians may misinterpret this as coming from the liver etc.

Question 31

What physiological changes occur to the GIT during pregnancy?

Answer 31

increased relaxation- constipation. billiary tract stasis (increased risk of gall stones and subsequent pancreatitis) Due to the action of progesterone which relaxes smooth muscle.

Question 32

What happens to plasma calcium levels during pregnancy? How does this change come about?

Answer 32

-they increase, to help mineralise the skeleton of the fetus. Due to increased levels of PTH and calcitonin, which increase kidney reabsorption and calcium absorption at the intestines.

Question 33

What happens if calcium intake is not enough during pregnancy?

Answer 33

The fetal skeleton still gets mineralised, Calcium is taken from the maternal skeleton via the actions of calcitonin.

Question 34

What haematological effects occur in pregnancy?

Answer 34

-prothrombotic state -increased risk of thromboemboi. -increased risk of anaemia -

Question 35

Why is the maternal body in a prothrombtic state during pregnancy?

Answer 35

In preparation for partuition, in which there will be blood loss. by increasing clotting factors this will limit blood loss from the mother.

Question 36

Why is there an increased risk of thromboembolism during pregnancy?

Answer 36

- changes to blood flow- Systemic venodilation leads to increased stasis - changes to blood composition- pregnancy affects the make up of blood

Question 37

What are some causes of anaemia in pregnancy?

Answer 37

-dilutional/physiological anemia occurs because the blood volume increases but the red blood cell volume doesnt increase proportionally. iron deficiency anaemia- the growing fetus uses a lot of iron.

Question 38

What effects does pregnancy have on the immune system?

Answer 38

generalised immunosupression to prevent rejection of the fetus. haemolytic diseases of the newborn eg rhesus incompatibility antibody transfer disease- graves, hashimotos.

Question 39

What is pre-ecclampsia?

Answer 39

A state the can occur in human pregnancies which involves oedema, hypertension and proteinuria. It can lead to ecclampsia, which is fitting of the mother with no other definitive cause. It occurs as a result of plasma volume contraction and vasoconstriction.

Question 40

Why does hypertension occrur in a pre-ecclamptic mother?

Answer 40

There is systemic vasoconstriction (opposite to what is normally seem), The plasma volume contraction decreases blood flow to the placenta and fetus, so the compensate the maternal blood pressure is further increased.

Question 41

What CNS effects may pre-ecclampsia cause?

Answer 41

- headaches - vision changes - seizures - blindness

Question 42

What renal changes can occur due to pre-ecclampsia?

Answer 42

- proteinuria - oliguria - renal failure

Question 43

What heamatological changes may occur due to preeclampsia?

Answer 43

- DIC - thrombocytopenia - heamolysis - raised liver enzymes

Question 44

What is the treatment for pre-eclampsia?

Answer 44

Delivery of the baby. Until this is possible, the mother must be monitored closely and blood pressure managed.