Molar Pregnancy

Question 1

What is a molar pregnancy?

Answer 1

It occurs when there is a problem with the fertilised egg, resulting in a type of precancerous tumour that grows like a pregnancy inside the uterus

Question 2

What can occur if a molar pregnancy persists?

Answer 2

There is a risk of malignant tumour formation, known as choriocarcinoma

Question 3

What promotes early baby growth during pregnancy?

Answer 3

In the ovary, certain genes in the ova will be switched off by the female through the addition of methyl groups

These changes promote early baby growth

Question 4

What promotes early placental growth via trophoblast proliferation during pregnancy?

Answer 4

In the testis, different genes in the sperm will be switched off by the male through the addition of methyl groups

These changes promote early placental growth via trophoblast proliferation

Question 5

What are the two classifications of molar pregnancies?

Answer 5

Complete Molar Pregnancy

Partial Molar Pregnancy

Question 6

What is a complete molar pregnancy?

Answer 6

It occurs when two sperm cells fertilise an ovum that contains no chromosomes

These sperm then combine genetic material, resulting in an overgrowth of trophoblast cells due to too many of the father’s methylated genes

This abnormal cell division results in the growth of a tumour

Question 7

Will foetal material form in a complete molar pregnancy?

Answer 7

No

Question 8

What is a partial molar pregnancy?

Answer 8

A partial molar pregnancy occurs when two sperm cells fertilise a normal ovum at the same time

The new cell now has three sets of chromosomes

It divides and multiplies into a tumour

Question 9

Will foetal material form in a partial molar pregnancy?

Answer 9

Some fetal material may form

Question 10

What are the four clinical features of molar pregnancies?

Answer 10

Severe Morning Sickness

Vaginal Bleeding

Increased Bump Size

Thyrotoxicosis

Question 11

What four chemical abnormalities are associated with morning sickness?

Answer 11

Hyponatraemia

Hypokalaemia

Hypochloraemia

Metabolic alkalosis

Question 12

What are the five other causes of severe morning sickness?

Answer 12

Multiple pregnancies

Trophoblastic disease

Hyperthyroidism

Nulliparity

Obesity

Question 13

What are the three investigations used to diagnose a molar pregnancy?

Answer 13

Bloods

Ultrasound

Histology

Question 14

What three blood results indicate a molar pregnancy?

Answer 14

Increased Beta hCG Levels

Decreased TSH Levels

Increased Thyroxine Levels

Question 15

What features on an ultrasound scan indicate a molar pregnancy?

Answer 15

Snowstorm appearance

Question 16

When are molar pregnancies detected on an US?

Answer 16

During the first pregnancy ultrasound scan – booking scan

Question 17

How do we confirm a molar pregnancy after an abnormal US?

Answer 17

Histological examination of the mole after evacuation

Question 18

What are the two histological features of a molar pregnancy?

Answer 18

Enlarged abnormal chorionic villi

An overgrowth of trophoblast cells.

Question 19

How do we manage molar pregnancies?

Answer 19

We evacuate the uterus in order to remove the mole

In some cases, this procedure is not necessary due to the pregnancy ending naturally with a miscarriage

Question 20

How do we manage molar pregnancies after the mole has been evacuated?

Answer 20

We monitor hCG levels until they return to normal

Question 21

How do we manage molar pregnancies with persistent elevated hCG levels? Why?

Answer 21

We prescribe one dose of methotrexate

There is a risk that the mole will metastasise