2. Pregnancy

Question 1

The blastocyte should technically be rejected by the mother as it presents antigens from the father, local signalling prevents this happening.
Between which cells does signalling occur to stop the mother attacking the blastocyte?

Answer 1

Extravillous trophoblasts (blastocyte)

NK cells (mother)

Question 2

Why is the production of hCG by the trophoblast cells of the blastocyte important?

Answer 2

hCG signals the corpus luteum to continue secreting progesterone.
If progesterone secretion stopped, menstruation would occur and the endometrium would bleed out along with the blastocyte.

Question 3

What do pregnancy tests detect?

Answer 3

beta subunit of hCG (human chorionic gonadotrophin)

Question 4

How is pregnancy clinically dated?

Answer 4

Number of weeks since the beginning of the last menstrual period

Question 5

At what week can the gestational sac be seen in ultrasound?

Answer 5

Week 5

Question 6

What can be seen at week 6 on ultrasound?

Answer 6

Fetal pole

Yolk sac

Question 7

At what week can fetal limbs and movement be seen on ultrasound?

Answer 7

Week 8

Question 8

At what week can a fetal heartbeat be seen on ultrasound?

Answer 8

Week 7

Question 9

In terms of circulation, what physiological changes occur during pregnancy?

Answer 9

↑ blood volume
↑ erythropoietin - but not as much as blood volume so you get a physiological anaemia.
↑ sodium + water retention - oestrogen stimulates renin-angiotensin system.
↑ cardiac output

Question 10

Blood pressure falls at the start of pregnancy and then rises again at the end of pregnancy.
True or False?

Answer 10

TRUE

Question 11

What can a persistent BP > 150/90mmHg during pregnancy be a sign of?

Answer 11

Pre-eclampsia

high bp, proteinuria, peripheral oedema, more likely to develop hypertension in future

Question 12

Which of these clotting factors is increased during pregnancy?
I
III
V
VI
VII
VIII
IX
X
XI
XII

Answer 12

I
V
VII
VIII
IX
X
XII

Question 13

Why is there an increased risk of thromboembolism in pregnancy?

Answer 13

↑ clot formation
(thromboplastin, fibrinogen, fibrin)
↓ clot lysis
(antithrombin, plasminogen, plasmin)

Question 14

How do pregnant women compensate for an increased demand of oxygen?

Answer 14

1. ↑ tidal volume
2. ↑ alveolar ventilation
3. vital capacity unchanged (max amount of air that can be expired from the deepest breath possible)

Question 15

The renin-angiotensin-aldosterone system is increased during pregnancy.
True or False?

Answer 15

FALSE

only during 1st trimester

Question 16

What effect does pregnancy have on GFR and blood flow?

Answer 16

↑ Blood flow

↑ GFR

Question 17

Bladder capacity decreases during pregnancy.

True or False?

Answer 17

True

Question 18

Why might pregnant women experience constipation?

Answer 18

↑ transit time, therefore ↑ water reabsorption, leading to constipation.