Pregnancy

Question 1

Stages from fertilisation to implantation

Answer 1

Zygote (fertilized ovum)

Early cleavage (4-cell stage)

Morula (3-4 days post-fertilization)

Blastocyst (4-5 days post-fertilization)

Implantation (6 days post-fertilization)

Trophoblast

Question 2

Peter Medawar

Answer 2

Fetal allograft survival

• antigenic immaturity
• placental protection
• blocking antibodies
• immune privilege

Question 3

What is decidua?

Answer 3

Decidua is the term for the uterine lining (endometrium) during a pregnancy, which forms the maternal part of the placenta. It is formed under the influence of estrogen and forms highly characteristic cells.

Question 4

What is villous trophoblast?

Answer 4

Inert (doesnt move // chemically unreactive)

Question 5

Extravillous trophoblast

Answer 5

• Only class I human leucocyte antigens
• less attractive to cytotoxic T-cells
• Enables binding to NK cells

Question 6

What is the signigicance of NK cells?

Answer 6

• Unique to luteal (secretory) phase of cycle
• Regulated by progesterone
• Capable of facilitating/ impeding trophoblast invasion
• Main source of decidual cytokines

Question 7

What is hCG produced by?

Answer 7

Trophoblast cells

Question 8

What does hCG do in terms of corpus luteum?

Answer 8

It continues to stimulate the corpus luteum (which is a structure that produces progesterone) - vital for fetal survival

Question 9

Imaging and clinical dating - what happens in week 5,6,7,8

Answer 9

5 - gestation sac
6- fetal pole, yolk sac
7 - fetal heart activity
8 - fetal limbs, movements

Question 10

What happens to the level of hCG, oestrogen and progesterone throughout pregnancy?

Answer 10

hCG levels peak at the start

Oestrogens and progesterone gradually increase and peak near parturition

Question 11

What are some of the physiological changes in pregnancy? (CARDIO)

Answer 11

• BLOOD VOLUME increases (40% increase)
• Red blood cells increase
• Anaemia
• Oestrogen stimulation of renin-angiotensin-aldosterone leads to sodium and water retendion

Question 12

What can persistent high BP be in indication of in pregnancy?

Answer 12

Pre-eclampsia

which is high BP, proteinuria and peripheral oedema

Question 13

What are some of the consequences of cardiovascular changes?

Answer 13

Fainting, haemorrhoids and varicose veins

Question 14

What happens in terms of coagulation during pregnancy?

Answer 14

Increased clot formation (due to increase fibrinogen, fibrin, thromboplastin)
Decreased clot lysis (due to antithrombin, plasminogen, plasmin)

Question 15

What are the respiratory changes?

Answer 15

Increase in oxygen consumption
Increase tidal volume
Increase in alveolar ventilation

Question 16

What are the renal changes?

Answer 16

Increase in renal blood flow
Increase in glomerular filtration rate
Bladder capacity decreases
Uteric dilatation
Urinary tract infections

Question 17

What are the gastrointestinal changes?

Answer 17

Altered appetite (cravings)
Constipation (greater water reabsorption)
Nausea vomitting
Decrease in gastric motility