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Human Reproduction > Pregnancy > Flashcards

Flashcards in Pregnancy Deck (55):
1

What is the role of progesterone in early pregnancy?

1. Suppress milk secretion
2. Suppress uterine contractions
3. Suppress hypothalamus and pituitary

2

What is the role of oestrogen in early pregnancy?

1. Increase uterine blood flow
2. Increased vessel growth

3

What occurs to the progesterone:oestrogen ratio in late pregnancy?

Stable progesterone with increasing oestrogen

1. Initiates parturition
2. Initiates lactation

4

Give five roles of oestrogen during pregnancy

1. Priming agents, including receptors
2. Growth of uterus and mammary tissue
3. Behavioural effects
4. Feedback on hypothalamus
5. Increases uterine blood flow

5

Give five roles of progesterone during pregnancy

1. Growth of endometrium and myometrium
2. Growth of mammary tissue
3. Behavioural effects
4. Negative feedback on hypothalamus
5. Inhibition of smooth muscle

6

How does the maternal pituitary gland change during pregnancy?

Increases in size by 30-50%

7

When is increased pituitary size clinically significant?

1. Acromegaly, with an already enlarged pituitary gland, may compress the optic chiasm leading to blindness

2. Vascular accident during delivery can lead to Sheehan's syndrome

8

What is Sheehan's syndrome?

1. Failure to lactate and resume menstrual cycles
2. Associated with post-partum haemorrhage

9

What mediates increased calcium uptake?

Increase PTH and 1,25DHCC

10

What mediates increased levels of adrenal cortical hormones?

Oestrogen-induced increase in binding globulins

11

What is the average weight gain in pregnancy?

12.5kg

12

Who tends to gain more weight during pregnancy?

Younger, lighter women

13

What contributes to weight gain during pregnancy?

60% water

2.3L in fetus
2.1L in placenta, uterus and amniotic cavity
1.3L in maternal tissue fluid
1.25L extra plasma

>3kg fat deposition

14

How does blood volume change in pregnancy?

40% increase in plasma volume due to upregulation of renin-angiotensin system

Haemodilution as red cell mass increases less than plasma increase

15

What causes increased red blood cell mass?

Increased erythropoiesis

16

How does clotting change?

1. Platelet count falls
2. Clotting factors increase

17

How does blood flow change?

Increased cardiac output and heart rate

Decreased resistance

Increased flow to kidneys and skin

18

What is transient high blood pressure?

Mild rise in BP during pregnancy or soon after delivery

Not accompanied by oedema or proteinuria

Begins after midpoint of pregnancy

19

What is pre-eclampsia?

Commonest cause of hypertension during pregnancy

ABP of at least 140mmHg/90mmHg

Oedema and proteinuria

20

Who is most at risk of pre-eclampsia?

1. First time mothers
2. Younger than 17 or older than 35
3. Family history of pre-eclampsia

21

What are the three causes of respiratory changes?

1. Space occupying lesion in abdomen puts upwards pressure on diaphragm
2. Increased oxygen consumption
3. Circulating hormone levels

22

When is breathlessness during pregnancy relieved?

1. Pelvic ligament softening at 36 weeks
2. Fetal head descends into pelvis and engages, relieving pressure

23

What does pulmonary ventilation increase to?

10L per min

24

What causes increase in pulmonary ventilation?

Increased tidal volume

25

What occurs to arterial pCO2 during pregnancy?

Decreases due to increased alveolar ventilation

26

What are the gastrointestinal changes that occur in pregnancy?

1. Decreased salivary pH causes caries
2. Increased abdominal pressure causes heartburn
3. Reduced gastric tone and motility causes nausea
4. Piles

27

What are the renal changes that occur in pregnancy?

1. Increased GFR due to increased plasma flow
2. Increased aldosterone
3. Sodium retention for fetal growth and volume expansion
4. Increased erythropoietin production

28

Which hormones induce metabolic changes in pregnancy?

1. Sex steroids
2. Human placental lactogen
3. Cortisol

29

How does maternal glucose regulation change?

1. Insulin resistance
2. Glucose diverted to fetus
3. Proliferation of pancreatic beta cells to compensate for insulin resistance
4. Can lead to gestational diabetes

30

What are the early behavioural changes in pregnancy?

Relate to food acquisition

Increased thirst and appetite, cravings and aversions, nausea and vomiting

31

What are the late behavioural changes in pregnancy?

Sense of fatigue

Reduced food intake

Nesting/restlessness

32

What is the proxy measure of intrauterine growth?

Birth weight

33

What are the three causes of a small birth weight?

1. Genes
2. Prematurity
3. Intrauterine growth restriction

34

What are the five maternal factors influencing intrauterine growth?

1. Uterine size
2. Nutrition
3. Parity
4. Socioeconomic and other environmental factors
5. Diseases

35

What is the evidence for the effect of uterine size on intrauterine growth?

Reciprocal crosses between Shire and Shetland ponies

Multiple pregnancies

36

What are the most important fetal endocrine factors for influencing intrauterine growth?

1. Insulin
2. Thyroid hormones

37

What is the effect of fetal insulin on fetal growth?

1. Decreased bodyweight
2. Increased fat deposition

38

What is the effect of thyroid hormones on fetal growth?

1. Increased bodyweight
2. Muscle, CNS, bones, wool

39

What is the effect of glucocorticoids on fetal growth?

1. Decreased bodyweight
2. Maturational effects on liver, lungs and gut

40

What does IGF-1 contribute to the development of?

1. Liver
2. Bones

41

What does growth hormone contribute to the development of?

Fat deposition

42

What are the properties of fetal haemoglobin?

1. Greater intrinsic oxygen affinity
2. Reduced 2,3DPG affinity

43

What are the two shunts in the fetal heart?

1. Foramen ovale
2. Ductus arteriosus

44

How does the fetal circulation differ from adult circulation?

1. Supplies placenta (55%)
2. CO is 4x greater
3. Two sides act in parallel rather than in series
4. Bypasses lungs

45

What are the changes in fetal lungs in preparation for birth?

1. Breathing movements that facilitate normal lung development
2. Development of surfactant and elastin in the lungs

46

What are the changes in fetal nutritional activity in preparation for birth?

1. Capacity for hepatic gluconeogenesis
2. Morphology and digestive capacity of the gut
3. Hepatic glycogen deposition
4. Hepatic gluconeogenic enzyme activities
5. Activities for gut digestive enzymes

47

What are the prepartum effects of cortisol on the liver?

Increased glycogen deposition

48

What does the maturation of lung, liver, kidney and gut rely on before birth?

Increase in glucocorticoid secretion from the fetal adrenal

49

Why are premature infants at risk of neonatal hypoglycaemia?

They have not had enough time to develop glycogen stores as they have not had enough cortisol

50

How does cortisol affect fetal concentrations of other hormones?

Increases tri-iodothyronine

Increases adrenaline

51

What are trio-iodothyronine and adrenaline important for?

Maturation or functional activation of key tissues essential for neonatal survival

52

What does the maturation of lung, liver, kidney and gut rely on before birth?

Increase in glucocorticoid secretion from the fetal adrenal

53

Why are premature infants at risk of neonatal hypoglycaemia?

They have not had enough time to develop glycogen stores as they have not had enough cortisol

54

How does cortisol affect fetal concentrations of other hormones?

Increases tri-iodothyronine

Increases adrenaline

55

What are trio-iodothyronine and adrenaline important for?

Maturation or functional activation of key tissues essential for neonatal survival