Physiology of pregnancy and lactation

Question 1

What happens in day of conception

Answer 1

Fertilisation of the egg by sperm in the ampulla of the uterine tube

Question 2

during which days does the blastocyst transport into the uterus

Answer 2

3-5

Question 3

During which days does the blastocyst attach to the endometrium

Answer 3

5-8

Question 4

In the blastocyst, the inner cell mass becomes the embryo/placenta
and the outer cells become the embryo/placenta

Answer 4

inner cell mass becomes embryo

outer cells become placenta

Question 5

What are trophoblasts

Answer 5

Cells that line the blastocyst

Question 6

What is decidual tissue

Answer 6

specialised tissue of the endometrium formed during the secretory phase that has embryo receptive properties

Question 7

At which day is the blastocyst completely embedded in the endometrium

Answer 7

day 12

Question 8

which tissues is the placenta derived from

Answer 8

trophoblasts and decidual tissue

Question 9

What are syncytiotrophoblasts and what do they do

Answer 9

They are multinucleate cells derived from trophoblasts

They invade the decidua and break down capillaries to form cavities of maternal blood

Question 10

How are placental villi formed

Answer 10

they are projections from the embryo sent into the syncytiotrophoblasts

Question 11

There is direct contact between maternal and foetal blood circulations, true or false

Answer 11

FALSE, there is no direct contact, they are separated by a thin layer of tissue

Question 12

By which week of pregnancy should the placenta and foetal heart be functional

Answer 12

Week 5

Question 13

What provides early nutrition to the embryo

Answer 13

Trophoblasts

Question 14

What does hCG signal to the corpus luteum to secrete

Answer 14

Progesterone

Question 15

What influence does progesterone have on decidual cells

Answer 15

Causes decidual cells to secrete glycogen, proteins and lipids

Question 16

Foetal oxygen rich blood goes to foetus via umbilical vein/artery
Maternal oxygen poor blood flows back through ?

Answer 16

foetal oxygen rich blood - umbilical vein

maternal oxygen poor blood - uterine veins

Question 17

What are the 3 factors that facilitate oxygen supply to the foetus

Answer 17

1. Foetal Hb - can carry more oxygen
2. Higher Hb concentration - 50% more than adults
3. Bohr effect - can carry more O2 when there is low CO2 rather than high CO2 levels

Question 18

In which direction do Fe and Ca move, mother to child or child to mother

Answer 18

Mother to child only

Question 19

List some teratogens that can cross the placenta

Answer 19

Thalidomide 
Phenytoin 
Na valproate 
ACEI/ARBs 
Carbamazepine 
Coumarins 
Tetracyclines 
Opioids 
Cocaine 
Alcohol 
Nicotine 
Heroin 
Caffeine

Question 20

what weeks does hCG peak

Answer 20

8-12 (~10)

Question 21

What is another name for Human Chorionic Somatomammotrophin (HCS)

Answer 21

Human placental lactogen (HPL)

Question 22

When is HPL produced

Answer 22

Week 5 of pregnancy and gradually increases

Question 23

What are the functions of HPL

Answer 23

Growth hormone like effects - builds protein
Reduces insulin sensitivity
Breast development

Question 24

What are the functions of progesterone

Answer 24

Development of decidual cells
Decreases uterine contractility
Preparation for lactation

Question 25

Which hormones increase and decrease uterine contractility

Answer 25

Progesterone decreases | Oestrogen increases

Question 26

What are the functions of oestrogen

Answer 26

Enlargement of uterus Increase uterine contractility Relax ligaments

Question 27

What happens to serum hCG every 48 hours

Answer 27

Levels double

Question 28

Why is it useful to monitor hCG levels

Answer 28

``` ectopic pregnancy miscarriage ongoing viable pregnancy multiple pregnancy molar pregnancy ```

Question 29

What are the cardiovascular adaptation that occur to the mother in pregnancy

Answer 29

Increased cardiac output to meet demands or uteroplacental circulation subtle ECG changes - right axis deviation functional murmurs heart sounds

Question 30

What haematological changes occur in the mother in pregnancy

Answer 30

Increased plasma volume Erythropoesis Decreased Hb concentration from dilution (^PV) Iron supplementation may be needed

Question 31

What respiratory adaptations occur in the mother in pregnancy

Answer 31

O2 consumption increases PCO2 decreases RR + TV increase Due to increasing progesterone levels and enlarging uterus

Question 32

What renal adaptations occur in the mother in pregnancy

Answer 32

increased plasma renal flow and increased GFR | increased reabsorption of ions and water

Question 33

what is pre eclampsia

Answer 33

pregnancy induced hypertension and proteinuria after 20 weeks gestation

Question 34

What is eclampsia

Answer 34

Extreme pre eclampsia, lethal without treatment

Question 35

What is the normal average weight gain for a woman in pregnancy

Answer 35

11 kg - foetus 3.5kg - extra embryonic fluid/tissue 2kg - uterus 1kg - breasts 1kg - body fluid 2kg - fat 1kg

Question 36

What are the 2 phases in pregnancy in relation to metabolism

Answer 36

phase 1 = mother's anabolic/building phase during 1-20wk | phase 2 = accelerated starvation/mothers catabolic phase 21-40wk, foetus has high metabolic demands

Question 37

What hormones cause insulin resistance in pregnancy

Answer 37

HPL, cortisol, growth hormone

Question 38

What are the recommendations for folic acid supplementation

Answer 38

400ug normally 5mg if obese, NTD history, AED, taken 3 months pre and post conception

Question 39

What supplements are required

Answer 39

``` Vitamin D Iron Calcium Vitamin B Protein ```

Question 40

What happens to the oestrogen:progesterone ration during parturition

Answer 40

Oestrogen levels rise | Progesterone levels fall

Question 41

What does oxytocin do during delivery and where does it come from

Answer 41

Comes from posterior pituitary | increases contractility and excitability of uterus

Question 42

List factors which increase uterine contractility

Answer 42

``` Oestrogen Oxytocin Mechanical stretching of uterus by foetus Cervical stretching Foetal hormones ```

Question 43

What are Braxton Hicks contractions

Answer 43

Tightenings, painless Not proper contractions Happen more towards end of pregnancy

Question 44

What happens in positive feedback during delivery

Answer 44

foetal head stretched cervix which releases more oxytocin, prostaglandins which in turn cause uterine contractions which causes cervical stretch cycle repeats

Question 45

What are the stages of labour

Answer 45

1st stage = cervical dilatation 2nd stage = delivery of baby through birth canal 3rd stage = expulsion and delivery of the placenta

Question 46

What effect does oestrogen have on lactation

Answer 46

causes growth of ductile system | inhibits milk production

Question 47

What effect does progesterone have on lactation

Answer 47

development of lobular-alveolar system | inhibits milk production

Question 48

What happens to oestrogen and progesterone levels at birth

Answer 48

Their levels decrease

Question 49

Which hormones are needed for milk production

Answer 49

Prolactin (anterior pituitary) | Oxytocin (posterior pituitary)

Question 50

What is the milk let down reflex

Answer 50

Mechanoreceptors in nipple stimulated by suckling impulses go to spinal cord hypothalamus is stimulated oxytocin released from posterior pituitary milk ejected