Common Pathologies of Pregnancy

Question 1

describe the hormone levels in a normal ovarian cycle.

Answer 1

• oestrogen peaks about day 14
• progesterone rapidly increases from day 14 and decreases again by day 28 if pregnancy is not achieved
• if pregnancy is achieved, it continues beyond day 28

Question 2

what does progesterone do once an egg has been fertilised?

Answer 2

thickens endometrial lining and converts it into decidua

• increases vascularity
• stromal cells enlarge between glands and vessels and become procoagulant -> stops bleeding and leads to cessation of menstrual periods

Question 3

describe the chorion

Answer 3

outer edge contains trophoblast cells which produce beta- human chorionic gonadotrophin

Question 4

what is the function of B-hCG?

Answer 4

stimulates corpus luteum to produce progesterone which stops decidua from shedding

Question 5

what hormone forms the basis of pregnancy tests?

Answer 5

B-hCG

Question 6

describe the process of implantation.

Answer 6

• chorion burrows into decidua
• trophoblast cells stream off to invade mother’s blood vessels and link them up with the foetus
• chorionic villi covered in trophoblast cells move into decidua
• decidual stromal cells are procoagulant and help stop bleeding when trophoblast cells invade mother’s blood vessels
• chorionic villi are bathed in mother’s blood forming the forerunner of the placenta

Question 7

what is an ectopic pregnancy?

Answer 7

pregnancy which occurs in the wrong anatomical site

Question 8

what is the most common site of ectopic pregnancy?

Answer 8

Fallopian tube

Question 9

what predisposes to rupture in ectopic pregnancy?

Answer 9

Lack of proper decidual layer and small size of fallopian tube

Question 10

what happens in normal pregnancy to promote growth of the baby and the placenta?

Answer 10

• mum switches off certain genes in her eggs by methylating them
• dad switches off certain genes in his sperm by methylating them
• mum and dad’s changes lead to different genes being switched off
• mum’s changes promote early baby growth
• dad’s changes promote early placenta growth via trophoblast proliferation

Question 11

what is the pathogenesis behind a molar pregnancy?

Answer 11

• often caused by 2 sperm fertilising 1 egg with no chromosomes
• results in imbalance of methylated genes causing trophoblast overgrowth
• leads to no or all but non-existent foetal growth

Question 12

what can happen if a molar pregnancy persists?

Answer 12

• form of precancer of trophoblast cells

- can give rise to a malignant tumour called a choriocarcinoma

Question 13

how is a molar pregnancy treated?

Answer 13

removal of pregnancy

• if BhCG returns to normal then no further treatment is required
• if BhCG stays high (persistent disease) then cure with methotrexate

Question 14

what are the associated problems of diabetes in pregnancy?

Answer 14

• malformations
• huge babies that obstruct labour
• IUD (probable sudden metabolic and hypoxic problems)
• neonatal hypoglycaemia

Question 15

what should those with diabetes do before becoming pregnant?

Answer 15

obtain good glucose control before conception (to prevent malformations) and then all the way through pregnancy (to prevent metabolic complications)

Question 16

why do women with diabetes tend to have macrosomic babies?

Answer 16

• effects of too much glucose in the mother
• glucose crosses the placenta and raises babies blood glucose
• insulin goes up in the baby
• baby cannot reduce glucose as mum keeps sending more across the placenta
• long-term high insulin and high glucose leads to massive growth

Question 17

what can ascending infection in the mother cause ?

Answer 17

acute chorioamnionitis

- can affect baby’s brain leading to conditions such as cerebral palsy in later life or even IUD

Question 18

how does chorioamnionitis lead to neurological damage in the foetus?

Answer 18

mum’s neutrophils produce a cytokine storm

this activates brain cells which then get damaged by normal hypoxia of labour

Question 19

Do opiates cross the placenta?

Answer 19

Yes and baby can get addicted to them

Question 20

How do opiate addicted babies usually do?

Answer 20

Pregnancy often goes well if mother is eating properly

Question 21

How is an heroin addicted baby treated once it is born?

Answer 21

• Immediate withdrawal from heroin when the baby is born

- Later withdrawal from methadone

Question 22

What is a placental abruption?

Answer 22

Separation of the placenta from the uterine wall

Question 23

What effect does placental abruption have on the baby?

Answer 23

-Decreases baby’s supply of oxygen and results in hypoxia

Question 24

What can placental abruption often cause in the mother?

Answer 24

Antepartum haemorrhage

Question 25

How can varying degrees of bleeding occur as a result of placental abruption?

Answer 25

Placenta may separate in different places which can result in different degrees of bleeding

• Vaginal bleeding
• Formation of localised haematoma

Question 26

What can cause placental abruption?

Answer 26

• Hypertension
• Trauma (including abuse)
• Other including cocaine use

Question 27

Give some causes of miscarriage.

Answer 27

• Chromosomal abnormality
• Infection
• Maternal issues such as ill-health, trauma or hormonal problems

Question 28

How can chorioamnionitis present in the mother?

Answer 28

• Mother can be ill with fever and raised neutrophils in the blood
• Mother be well

Question 29

How can chorioaminionitis present in the baby?

Answer 29

• IUD
• Illness in the 1st days of life leading to NICU stay
• Cerebral palsy later in life

Question 30

What are the typical organisms involved in chorioamnionitis?

Answer 30

Perineal or perianal flora including E.coli

Question 31

What is over twisted cord a common cause of?

Answer 31

IUD and neonatal illness