Session 8 - Preggers changes Flashcards Preview

Semester 4 - Reproductive System > Session 8 - Preggers changes > Flashcards

Flashcards in Session 8 - Preggers changes Deck (31)
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1
Q

Give 6 main physiological changes in pregnacny

A
o	Cardiovascular system
o	Urinary system
o	Respiratory system
o	Metabolic changes
   	Carbohydrate
   	Thyroid hormones
o	Gastrointestinal System
o	Immune system
2
Q

What are the five main CVS changes of pregnancy

A
o	Blood volume increases
o	Cardiac output increases
o	Stroke volume increase
o	Heart rate increases
- Blood pressure DECREASES
3
Q

What causes hypotension in T1 and T2?

A

Progesterone decreases systemic vascular resistance

4
Q

What causes hypotension in T3

A

 T3 – Aortocaval compression by gravid uterus. Reduced return to the heart.

5
Q

Give four main effects of pregnancy on the urinary system

A

o Renal plasma flow increases
o Glomerular Filtration Rate (GFR) increases
 ~55%
o Filtration capacity intact
o Functional renal reserve decreases as GFR increases

6
Q

Why does urinary stasis occur in pregnancy?

A

Progesterone relaxes the smooth muscle in the walls of the ureters, which can result in stasis, hydroureter, UTIs and pyelonephritis.

7
Q

Why is pyelonephritis dangerous in pregnancy?

A

Pre-term labour

8
Q

What is the main effect of foetus on respiratory system?

A

Diaphragm is displaced

9
Q

What 7 changes occur in respiratory system?

A
	O2 consumption increases 20%
	Decreases functional residual capacity
	Vital capacity unchanged
	Tidal volume increases
	Respiratory minute volume increased
	Alveolar ventilation rate increased
	Respiratory rate unchanged
10
Q

What does progesterone generate in resp system?

A

Physiological hyperventilaton, so mother can blow off the extra CO2 the foetus produces.

This leads to respiratory Alkalosis, which the kidneys compensate for by producing and reabsorbing less bicarbonate.

11
Q

How is carbohydrate metabolism changed in pregnancy?

A

Glucose and amino acid metabolism are altered in pregnancy to favour nutritional supply to the fetus

12
Q

What does progesterone stimulate in terms of carbohydrate metabolism?

A

Progesterone stimulates appetite in the first half of pregnancy and diverts glucose into fat synthesis

13
Q

What does oestrogen stimulate in terms of carb metabolism?

A

. Oestrogen stimulates an increase in prolactin release, which, along with other hormones, generates a maternal resistance to insulin

14
Q

Why is it good to increase insulin resistance in mother?

A

More glucos for foetus

15
Q

How are mothers energy needs met later in the pregnancy?

A

etabolising peripheral fatty acids.

16
Q

What is gestational diabetes?

A

o Carbohydrate intolerance first recognised in pregnancy and do not persist after delivery
o Risks associated with poor control
 Macrosomic fetus
 Stillbirth
 Increased risk of congenital defects
o Oral glucose tolerance test required

17
Q

How do pancreatic b cells meet increased demand for insulin secretion

A

by b-cell hyperplasia and hypertrophy as well as the increased rate of insulin synthesis in the b-cell.

18
Q

Why does gestational diabetes arise?

A

In some women, the endocrine pancreas is unable to respond to the metabolic demand of pregnancy and the pancreas fails to release the increased amounts of insulin required.

19
Q

What happens to lipid metabolsim in pregnancy?

A

o Increase in lipolysis from T2
o Increase in plasma concentration of free fatty acids on fasting
 Free fatty acids provide substrate for maternal metabolism, leaving glucose for the fetus
o Increased utilisation of free fatty acids increases the risk of Ketoacidosis
 Combined with pregnancy’s state of compensated respiratory alkalosis this can be extremely bad.

20
Q

What happens to thyroid in pregnancy?

A

o Thryoid binding globulin production increased
o T3 increased
o T4 increased
o Free T4 in normal range due to increased binding globulin

o hCG has a direct effect on the Thryoid, stimulating T3 and T4 production
 TSH can be decreased in normal pregnancies as a result of negative feedback from T3 and T4 produced due to hCG secretion

21
Q

What anatomical GI changes occur during preg?

A

o Alterations in the positions of viscera

 E.g. appendix moves from RLQ to LUQ as the uterus enlarges

22
Q

What physiological GI changes occur in preg?

A

o Smooth muscle relaxation by Progesterone
 GI – Delayed emptying
 Biliary tract – Stasis
 Pancrease – Increased risk of pancreatitis

23
Q

What happens to blood in preg?

A

o High amount of fibrin deposition at the site of implantation
 Increased fibrinogen and clotting factors
 Reduced fibrinolysis
o Stasis, venodilation

24
Q

Why is pro-thrombotic state sometimes disease causing?

A

o Results in Thromboembolic disease in pregnancy

 Cannot give warfarin – Crosses the placenta and is teratogenic

25
Q

How does anaemia occur in preg?

A

o Plasma volume increases
o RBC mass also increases, but not to the same degree
o Physiological anamiea
 Not a true anaemia, just a mismatch between volume and haemocrit

o Anaemia due to iron and folate deficiency can also occur

26
Q

Why doesn’t mother attack foetus immunologically?

A

o Non-specific suppression of the local immune response at the materno-fetal interface

27
Q

Why is thyroid disease dangerous in perg?

A

o Graves disease and Hashimoto’s Thyroiditis
 Antibodies will cross the placenta and either stimulate TSH receptors on or destroy developing fetal thyroid respectively.

28
Q

Give three methods of antenatal screening

A
o	History and examination
   	Risk factors – E.g. for gestational diabetes
o	Blood test
   	Blood group
   	Haemoglobin
   	Infection
o	Urinalysis
   	Protein
29
Q

What is pre-eclampsia?

A

Normal Pregnancy
o Vasodilated
o Plasma-Expanded
o Blood pressure not raised in normal pregnancy

Pre-Eclamptic Pregnancy
o	Vasoconstricted
o	Plasma-Contracted
o	Raised blood pressure
o	Proteinuria
o	Pitting oedema
30
Q

Outline what you discussed with Alex in terms of alveolar ventilation

A

Respiratory rate does NOT increase to blow off CO2.

Instead, alveolar ventilation rate increases due to tidal volume increase.

31
Q

Define alveolar ventilation

A

(Tidal volume - Dead Space) * Respiratory Rate