Common Pathologies of Pregnancy

Question 1

If the egg is fertilised what happens to progesterone?

Answer 1

It doesn’t dip
It turns the endometrium into the decidua by increased endometrial thickness, vascularity and enlarging the stromal cells between vessels and making them become anticoagulant

Question 2

What is another name for the egg?

Answer 2

Chorion

Question 3

What lines the outer aspect of the chorion?

Answer 3

Trophoblast cells

Question 4

What is the function of trophoblast cells?

Answer 4

Production of beta-hCG which stimulates the CL to produce progesterone that stops the decidua shedding

Question 5

What hormone is picked up in pregnancy tests?

Answer 5

b-hCG

Question 6

What is the decidua?

Answer 6

Endometrium during pregnancy (forms maternal part of placenta)

Question 7

How is the placenta formed?

Answer 7

Fertilised egg borrows into decidua
Chorionic villi covered in trophoblast cells invade mothers vessels
Decidual stromal cells are procoagulant and prevent excess bleeding
Eventually chorionic villi are bathed in mother’s blood

Question 8

Why is are the tubes more prone to rupture in ectopic pregnancy as opposed to uterine pregnancy?

Answer 8

Tubes lack proper decidual layer (so trophoblasts invade into mucosa and muscle) and also small size of tubes
Both predispose to rupture and haemorrhage

Question 9

What happens in normal pregnancy in terms of the egg and sperm’s genes and fusion of the gametes?

Answer 9

Mum and dad switch off certain genes in their gametes by methylation
Ovum and sperm fuse (23 chromosomes each)
Mum’s changes –> growth of the baby
Dad’s changes promote trophoblast proliferation and hence placenta formation

Question 10

What are the causes of molar pregnancy?

Answer 10

Many causes but often caused by 2 sperm fertilising an egg with no chromosomes

Question 11

What results in molar pregnancy?

Answer 11

Imbalance in methylation –> massive overgrowth of trophoblast cells and therefore overgrowth of placenta

Question 12

What can molar pregnancy lead to?

Answer 12

It is a pre-cancer of the trophoblasts

Can lead to malignant choriocarcinoma

Question 13

How do you manage molar pregnancy?

Answer 13

If b-hCG starts to return to normal can leave it

If b-hCG continues to rise then give methotrexate

Question 14

Why do diabetic mothers have such big children?

Answer 14

Reduced insulin in mother –> high BG –> glucose crosses placenta –> high BG in baby –> high insulin in baby –> massive growth –> susceptibility to IUD

Question 15

What complications can result of diabetes in pregnancy?

Answer 15

Malformations
Huge babies that obstruct labour
IUD (due to metabolic/hypoxic problems)
Neonatal hypoglycaemia (due to persistent hyperinsulinaemic hypoglycaemia)

Question 16

How can diabetic mothers prevent complications to the baby?

Answer 16

Good glucose control

Question 17

How does opiate use affect fetal development?

Answer 17

It doesn’t so long as mother eats well
But opiates cross placenta and will get immediate heroine withdrawal at birth and later withdrawal from methadone (weeks later, overfeeding, constant mouthing movements etc.)

Question 18

How do you manage heroine withdrawal in a neonate?

Answer 18

Phenobarbitone and wean off

Question 19

What must you be mindful of when treating withdrawal?

Answer 19

Can seizure

Question 20

How does cocaine affect your BVs?

Answer 20

Vasoconstrictor
Constricts BVs of the septal cartilage –> collapse of bridge of nose
Constricts BVs of heart –> scarring and death
In pregnancy, constricts BVs to uterus

Question 21

How many doses of cocaine is necessary to cause damage to the foetus?

Answer 21

Only 1

Could constrict vessels to uterus during kidney/eye/limb formation etc. –> abnormalities

Question 22

Apart from foetal abnormalities, what else can cocaine use during pregnancy increase the risk of?

Answer 22

Placental abruption and foetal death

Question 23

What is the commonest cause of IUD and neonatal illness?

Answer 23

Overtwisted cord

Question 24

What causes overtwisted cord?

Answer 24

Tends to be happy, healthy babies moving around a lot and turning their own cord

Question 25

What can overtwisted cord lead to?

Answer 25

IUD, hypoxic baby

Can cause foetal death from 15wks –> term

Question 26

What does an overtwisted cord look like?

Answer 26

Twists every 1.5-2cm as opposed to 5-6cm

Dark as opposed to light in colour

Question 27

What is placental abruption?

Answer 27

Separation of placenta from uterine wall –> bleeding/haematoma

Question 28

What are the consequences of placental abruption for the baby?

Answer 28

Hypoxic, IUD, seizures, lactic acidosis

Question 29

What can cause placental abruption?

Answer 29

HTN, trauma, cocaine

Question 30

Define pre-eclampsia

Answer 30

HTN leading to kidney disease (proteinuria)

Question 31

What are the consequences of pre-eclampsia?

Answer 31

Can get huge loss of albumin
HTN in pregnancy can lead to liver damage –> HELLP syndrome
Intracranial bleeds/strokes due to HTN in brain

Question 32

What is the aetiology of pre-eclampsia?

Answer 32

Placenta normally chews away at the smooth muscle around mum’s BVs so they can’t constrict and reduce BF to the uterus
In pre-eclampsia, there is failure to do this, and so placenta goes through periods of being well and poorly perfused
Placenta then produces hormones to make mum hypertensive so it is always well perfused