Molar pregnancy

Question 1

What is a molar pregnancy?

Answer 1

Abnormal fertilization leading to disordered placenta tissue development

Question 2

For a complete mole:
* What it consists of
* Is there fetal tissue
* Incidence
* Risk of malignancy

Answer 2

• Empty ovum fertilized with either 1 sperm that replicates (75-80%) OR 2 sperm –> diploid
• No evidence of fetal parts
• Incidence 1/1000
• Risk of malignancy = 15-25%

Question 3

For a partial mole:
* What it consists of
* Is there fetal tissue
* Incidence
* Risk of malignancy

Answer 3

• One set of maternal DNA and 2 sets of paternal DNA –> triploid
• Can have some fetal parts
• Incidence 3/1000
• Risk of malignancy = 0.5-4%

Question 4

What investigations should be done for a molar pregnancy?

Answer 4

• Bloods –> FBC, UCEs, LFTs, TFTs, G&H
• USS –> diagnosis
• CXR for metastases
• Histological examination of tissue for definitive diagnosis
• Serial serum beta-hCG until negative and ongoing monitoring for 6 months after a complete mole

Question 5

What information should be given to a woman with possible molar pregnancy

Answer 5

• Explain a molar pregnancy –> is a precancerous baby and NOT a baby
• Effectively treated with surgery +/- methotrexate
• Depending on the treatment, fertility may need to be postponed but is not affected
• 1/70 chance of recurrent molar pregnancy