GTD

• Gestational trophoblastic disease is group of pregnancy related tumours, two main groups:

  • pre-malignant (more common) - partial and complete molar pregnancy
  • Malignant conditions - invasive mole, choriocarcinoma, placental trophoblastic tumour
• Molar pregnancies:

  • Partial - one ovum with 23 chromosomes is fertilised by 2 sperm - produces cells with 69 chromosomes (triploidy)
  • Complete - ovum without any chromosomes is fertilised by one sperm which duplicates, or less commonly two different sperm - leads to 46 chromosomes of only paternal origin
  • Partial molar pregnancies contain foetal parts but complete do not
  • These tumours are usually benign but can become malignant and metastasise - invasive mole
• Risk factors:

  • extremes of reproductive age (<15 or >50)
  • Ethnicity - less common in black women, more common in Asian women
  • blood group - women with incompatible partner blood group
  • Previous gestational trophoblastic disease
• Presentation:

  • Vaginal bleeding and abdominal pain early in pregnancy
  • Hyperemesis - due to abnormally high hCG levels
  • Hyperthyroidism - high hCG levels stimulate thyroid
• On exam:

  • Larger than expected uterus
  • Soft and boggy consistency
• Investigations:

  • urine/serum hCG - markedly elevated at diagnosis and used in monitoring
  • Transvaginal ultrasound scan - complete mole will have characteristic snowstorm appearance
  • Histological examination of products of conception
  • In cases where metastatic spread is suspected - staging scans
• Management:

  • Register with a GTD centre for follow up and monitoring of future pregnancies
  • Evacuation of the uterus - follow up 3 weeks later with hCG measurement
  • Products of conception need to be sent for histological examination to confirm molar pregnancy
  • Anti-D prophylaxis if mother Rhesus negative
  • Chemotherapy may be required if hCG levels do not fall
  • Malignant disease - chemotherapy +/- surgical management