Molar pregnancy

Question 1

What is a hydatidiform mole?

Answer 1

A type of tumour that grows like a pregnancy inside the uterus.

Question 2

What are the 2 types of molar pregnancy?

Answer 2

1. Complete mole
2. Partial mole

Question 3

What is a complete mole?

Answer 3

Occurs when two sperm cells fertilise an ovum that contains no genetic material. The sperm then combine genetic material, and the cells start to divide and grow into a tumour called a complete mole - no fetal material will form.

Question 4

What is a partial mole?

Answer 4

Occurs when two sperm cells fertilise a normal ovum (containing genetic material) at the same time. The new cell will have three sets of chromosomes. The cell divides and multiplies into a tumour called a partial mole where some fetal material will form.

Question 5

How does a molar pregnancy behave?

Answer 5

Like a normal pregnancy where periods will stop and hormonal changes of pregnancy will occur.

Question 6

What indicates a molar pregnancy over a normal pregnancy?

Answer 6

1. More severe morning sickness (due to increased bHCG)
2. Vaginal bleeding
3. Increased enlargement of uterus (later in pregnancy, a large for dates uterus may be noted on exam)
4. Abnormally high HCG
5. Thyrotoxicosis (hCG can mimic TSH and stimulate thyroid to produce excess T3 and T4)

Question 7

What would you see on USS?

Answer 7

‘snowstorm appearance’

Confirm with histology of mole after evacuation.

Question 8

What is the management?

Answer 8

Involves evacuation of uterus to remove the mole - suction and curettage. Products of conception need to be sent for histological exam to confirm molar pregnancy. Patients have to be referred to gestational trophoblastic disease centre. HCG levels are monitored until they return to normal. If mother is rhesus negative, anti-D prophylaxis. Occasionally, the mole will metastasise & patient may require systemic chemotherapy (invasive mole).