Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Reproduction > Maternal adaptations to pregnancy > Flashcards

Maternal adaptations to pregnancy Flashcards

1
Q

What are the functions of progesterone during pregnancy?

A
  1. Growth of endometrium
  2. Growth of mammillary tissue
  3. Behavioural changes (e.g. increased appetite)
  4. Inhibition of uterine contractions
  5. Feedback suppression of hypothalamus (suppression of LH and FSH to inhibit menstrual cycle)
  6. Increased uterine glandular secretions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the functions of oestrogen during pregnancy?

A
  1. Increased uterine blood flow
  2. Promotion of uterine vasculature growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is relaxin secreted and what are its functions?

A

Origin: Corpus luteem (early), placenta (after luteolysis)

Functions: Softens ligaments of the pelvis and cervix in late pregnancy in preparation for birth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where is hPL secreted and what are its functions?

A
  • Origin: Placenta
  • Functions:
    1. Stimulates maternal appetite
    2. Promotes lipolysis (maternal use of fat as source of energy instead of glucose which is used by foetus)
    3. Growth of mammillary tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is PGH secreted and what are its functions?

A
  • Origins: Placenta
  • Functions:
    1. Promotes lipolysis and maternal use of fats as energy source
    2. Promotes gluconeogenesis and inhibits action of maternal insulin, which increases available glucose for fetus
    3. Suppresses maternal secretion of GH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is leptin secreted and what are its functions?

A
  • Origins: Placenta, adipose tissue
  • Functions:
    1. Promotes placental transport
    2. Peripheral resistance in mother means that it doesn’t have usual appetite suppresing effects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is prolactin secreted and what are its functions?

A
  • Origins: Anterior pituitary
  • Functions: Promotes lactation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the pathologies associated with the pituitary gland during pregnancy?

A
  1. Enlargement of the pituritary gland during pregnancy may cause compression of the optic chiasm, resulting in tunnel vision.
  2. Pituitary gland hypertrophy means that it also has an increased blood supply. This makes it vulnerable to ischaemia and infarction following large amounts of post-partum haemorrhage and the subsequent hypovolaemia that ensures, causing reduced pituitary function (post-partum hypopituitarism, Sheehan’s syndrome).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the changes in glucose metabolism that occur during pregnancy?

A
  1. Peripheral insulin resistance (due to PGH, hPL) causes hyperglycaemia.
  2. Same hormones also upregulate glycolysis and raises maternal blood levels of triglyceride.
  3. This switches maternal metabolism towards lipids and maximises glucose availability to fetus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the changes to the adrenal glands that occur during pregnancy?

A
  1. Increased activity of RAAS causes increased aldosterone secretion from the adrenal cortex.
  2. Secretion of CRH from the placenta promotes cortisol secretion from the adrenal cortex.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What changes in cardiac output are observed during pregnancy?

A

There is an increase in cardiac output throughout pregnancy, reaching a maximum of up to 40% by 20-28 weeks, which is maintained around this figure until parturition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What causes the changes in cardiac output observed during pregnancy?

A
  • Increased heart rate (by 10-20 bpm) and stroke volume (~30%).
  • These changes are mainly mediated by decreased peripheral vascular resistance (due to action of progesterone), causing reduction in blood pressure and reflex sympathetic stimulation of the heart; in addition to increased MSFP and VR due to increased TBV as consequence of renal changes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which organs have an increased demand for blood during pregnancy?

A
  1. Reproductive tissues (maternal-fetal circulation)
  2. Gut (increased absorption of nutrients)
  3. Kidneys (increased excretion of waste)
  4. Skin (increased heat dissipation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the effects of maternal position on cardiac output?

A

In the supine position (lying on back), the uterus compresses the IVC and compromises VR, resulting in a reduction of CO by ~25%.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What changes in blood pressure occur during pregnancy?

A
  1. There is initial drop in MAP below normal as a result of reduced TPR, due to vasodilation mediated by progesterone (through activation of eNOS and NO).
  2. However, this is compensated gradually by increased CO resulting in restoration of MAP as pregnancy progresses.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What changes in blood volume occur during pregnancy?

A
  1. There is an increase in TBV by ~50% in order to maintain the high CO required to compensate for the increased blood demand during pregnancy.
  2. The increase begins around week 6 and plateaus in 3rd trimester.
17
Q

What causes the changes in blood volume observed during pregnancy?

A
  • The increase in blood volume is mediated by 2 components:
    1. Increased plasma volume
    2. Increased RBC mass
  • Increased plasma volume is mediated by water retention and an increase in activity of the RAAS.
  • Red blood cell mass rises much more slowly compared to plasma volume, so there is an initial decrease in haematocrit. However, increase in erythropoietin and causes haematopoiesis, causing rise in haematocrit.
18
Q

What are the changes in the coagulative state of blood during pregnancy?

A

There is also a shift in the coagulation state of blood to a hypercoagulative state as a result of 2 changes:

  1. Increased levels of all coagulation factors except from XI and XIII
  2. Plasminogen activator inhibitor concentration increase (mainly due to PAI2 secretion from placenta)
19
Q

What are the changes in uterine blood flow observed during pregnancy?

A

~45 ml/min → ~750ml/min

20
Q

What are the renal changes observed during pregnancy?

A
  1. Increased GFR and renal blood flow
  2. Increased activity of RAAS and water retention
21
Q

What mediates increase in GFR and renal blood flow during pregnancy?

A
  1. Vasodilation of afferent and efferent arterioles due partly to relaxin and increased sympathetic tone.
  2. Increased blood flow as a result of CO.
22
Q

What mediates increased activity of the RAAS during pregnancy and what is its function?

A
  • Sympathetic stimulation and initial reduction in renal perfusion pressure due to fall in TPR (due to vasodilation).
  • Causes blood volume expansion required to maintain CO.
23
Q

What are the challenges posed by the fetus to the respiratory system?

A
  1. The increase in size of the uterus causes elevation of the diaphragm by ~4cm and reduction in total lung capacity.
  2. Increase in O2 demand due to the presence of the fetus.
24
Q

What are the respiratory changes that occur during pregnancy?

A
  • Increased excursion of diaphragm by 1-2 cm
  • Increased tidal volume by 40-50%
  • No change in respiration rate
  • Overall increase in ventilation rate by 50-70%
25
Q

What causes the respiratory changes oberved during pregnancy?

A
  • Relaxation of the ligaments in the thoracic walls that allows for expansion of the thoracic cavity in the lateral and antero-posterior dimensions.
  • Many respiratory changes are mediated by progesterone, which has the following effects:
    1. Increased sensitivity of chemoreceptors to CO2 causes increased stimulation, causing the increase in diaphragmic excursion.
    2. Relaxation of the tracheal/bronchial smooth muscles to reduce airway resistance.
26
Q

What are the physiological consequences of the maternal respiratory changes?

A

Decrease in blood PaCO2 causes increase in blood pH, resulting in chronic (compensated) respiratory alkalosis.

27
Q

What are the changes in appetite/food consumption observed during pregnancy?

A
  1. There is an increase in maternal appetite to increase amount of glucose and nutrient intake from the mother.
  2. There may be cravings for unusual foods in order to fulfil specific nutrient requirements.
  3. There is increased chance of nausea and vomiting (morning sickness), which is correlated strongly with increased levels of hCG.
28
Q

What are the changes to the GI tract motility that occur during pregnancy?

A
  1. There is relaxation of the LOS due to action of progesterone. This increases the ease by which food enters the stomach and so promotes feeding.
  2. NO-induced relaxation of intestinal smooth muscle causes reduction in mobility and increased absorption of nutrients from food. This is mediated by oestrogen.
29
Q

What mediates increased absorption of Ca2+ from gut during pregnancy?

A

Increase in Ca2+ transporters (active transport) density mediated by 1, 25 dihydroxycholecalciferol (1, 25-DHCC).

30
Q

What is the average maternal weight gain during pregnancy?

A

7-23 kg (12.5 kg average)

31
Q

What is the change in posture observed during pregnancy?

A

Increase in lordosis to maintain centre of gravity over hip joint for upright posture.

Human Reproduction (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions