Gestational Trophoblastic Disease
Definition
A molar pregnancy happens when tissue that normally becomes a foetus instead becomes an abnormal growth in the uterus. Even though it isn't an embryo, this growth triggers symptoms of pregnancy. (www.webmd.com)
- Benign Trophoblastic Disease (Hydatidiform Mole)
- Complete
- Partial
- Hydropic degeneration of trophoblast
- Persistent Trophoblastic Disease (often malginant)
- Invasive mole (confined to uterus)
- Choriocarcinoma (extra-uterine spread)
Epidemiology
- 1/750
- 98% cure rate
Aetiopathogenesis
Genetic d/o --> Ovum no nucleus/ 2 sperms enter
Complete = diploid (46 XY (90%)/ YY (10%))
Partial = triploid (69 XYY)
--> defective maternal immune response --> villi distended w nutrients --> poor vasculature formation --> embryo starve --> embryo absorbed --> trophoblast thrives
Pathology
Hydatidiform mole
Complete = tumour (vesicles) completely replace placenta (15% --> malignant)
Partial = foetus + tumour (0.5% --> malignant)
Malignant
Invasive = villi into myometrium
Choriocarcinoma = no villi, invade into bloodstream --> other organs
Clinical Features
Benign
PV bleed --> uterine contraction --> expulsion of grape like material/ Uterus larger than gestational dates, doughy to touch, no foetal HR, inc b-HCG, US = speckled look
Malignant
Same as benign but extremely high b-HCG (>100,000 IU/mL), US show spread
Management
If expelled, do nothing
If not, suction curettage then watch for bleeding. If bleed >21d, curettage. Then b-HCG weekly. If 3 consecutive N, test monthly for 6mo. If not (it's malignant!), methotrexate/ actinomycin D.
Source
Llewellyn-Jones. Fundamentals of Obstetrics and Gynaecology. 9th Ed 2010