Abnormal form of pregnancy in which a non-viable fertilized egg implants in the uterus or tube
Aetiology
- A complete mole occurs when two sperm cells fertilise an ovum that contains no genetic material (an 'empty ovum')
- These sperm then combine genetic material, and the cells start to divide and grow
- Complete moles have a higher risk of developing into choriocarcinoma
- Partial mole occurs when two sperm cells fertilise a normal ovum (containing genetic material) at the same time
- The new cell now has three sets of chromosomes (it is a haploid cell)
- The cell divides and multiplies into a tumour
Pathophysiology
- Overgrowth of placental tissue with chorionic villi swollen with fluid; giving picture of 'grape like clusters'
Clinical presentation
- Hyperemesis, hyperthyroidism, early onset pre-ecclampsia
- Varied bleeding and occasional history of passage of 'grapelike tissue'
- Fundus > dates on abdominal palpation
- Rare cases: shortness of breath (due to embolisation to lungs) or seizures (metastasis to brain)
Investigations
- USS - 'snow storm appearance'
- Provisional diagnosis can be made by ultrasound and confirmed with histology of the mole after evacuation
Management
- Surgical procedure (uterine evacuation) and tissue sent for histology to ascertain type
- After evacuation of a hydatidiform mole, the levels of b-hCG are expected to fall and pregnancy should be avoided for 1 year
- If they fail to drop, malignant choriocarcinoma should be suspected