Molar Pregnancy/ Hydatidiform Mole (H Mole)

- Benign disease of trophoblast with malignant potential
- Features due to ↑ HCG:
- Hyperemesis gravidarum
- Thyrotoxicosis
- B/L theca lutein cysts
- HTN < 20 weeks
Grossly:
- Identified by grape-like vesicles (hydropic villi filled with water).
Microscopy:
- Shows big hydropic villi.
Molar Pregnancy Types
Feature | Complete/Vesicular Mole | Partial Mole |
Pathogenesis | Empty ovum fertilized by 1 sperm | Normal ovum fertilized by 2 sperms |
Karyotype | Diploid: 46 XX | Triploid: 69 XXY |
Maternal Chromosome | - | + |
Extragenetic Material | Paternal | Paternal |
P/A Examination | Fundal height > POG | Fundal height ≤ POG |
Fetal Signs | Absent FHS, no fetal parts felt | == |
b-hCG Value (vs N) | ↑↑ | ↑ |
USG (IOC) | Snow storm appearance | Appearance of missed abortion |
HPE (Gold Standard) | Trophoblastic proliferation, villi + | == |
Fetal Tissue | No fetal tissue | Some fetal tissue + |
ㅤ | Negative | P57Kip2 Positive Mnemonic: P for Partial |
Risk of cancer | GTN - 15 % Choriocarcinoma - 4% | Choriocarcinoma - Negligible |
USG Finding:

- USG findings:
- Multiple Cystic Spaces in the uterus.
- No fetal parts.
- Snowstorm appearance
- d/t Hydropic degeneration of placenta
- Edematous villi
- B/L Theca Lutein Cyst
- d/t Increased Beta HCG
- Placentomegaly
Molar Pregnancy Management
- Primary Treatment:
- Suction evacuation
followed by Sharp curettage- Sample sent for HPE.
- Alternative (Age/Parity):
- If age >40 years + family complete:
- Total Abdominal Hysterectomy (TAH).
- Theca Lutein Cysts:
- Spontaneously regress (No specific management required).
- Follow-up (b-hCG):
- Weekly b-hCG levels until 3 consecutive findings are Normal/undetectable.
- F/b Monthly b-hCG for
6 months1 year - Pregnancy is Contraindicated during follow-up;
- OCPs preferred.
Gestational Trophoblastic Neoplasia (GTN)
GTN Features and Management
- IM > CCA > PSTT > ETT
Type | Common Occurrence | Management |
Invasive mole | m/c GTN after molar evacuation | Chemotherapy |
Choriocarcinoma | • M/c GTN after full-term pregnancy • M/c Cause: Molar pregnancy | Chemotherapy |
Placental Site Trophoblastic Tumour (PSTT) | After full term pregnancy | Hysterectomy + Chemotherapy |
Epithelioid Trophoblastic Tumour (ETT) | _ | Hysterectomy + Chemotherapy |
- HPE is not required to differentiate between GTN types.
- Mnemonic:
- Chori invade cheythal chemical ozhikkanam
- TT → hysTerectomy + chemoTherapy
GTN Signs & Symptoms
- Persistent bleeding.
- Persistent theca lutein cyst.
- Shock (Due to Invasive mole).
- Subinvolution of uterus.
- Metastasis: Lungs > vagina.

GTN Laboratory Investigations
Finding in Consecutive Weeks | Interpretation | ㅤ |
4 Weeks: Plateau hCG (within 10% of N range) | Invasive mole | Inside plate |
3 Weeks: ↑hCG >10% | Choriocarcinoma | Kudunnath Koori |
hCG detected >6 months (after suction evacuation) | GTN | ㅤ |
HPE | Shows GTN | ㅤ |
Type of Chemotherapy Based on Stage and WHO Score :
Stage | Risk Score (WHO) | Management |
1: Limited to uterus | _ | Single agent (NOT DOSE) chemotherapy: Multidose methotrexate (MTX) (On D1, D3, D5, D7 alternating with folinic acid) |
2: Pelvic spread 3: Spread to lungs | ≤ 6 (Low Risk) | ‘’ |
2: Pelvic spread 3: Spread to lungs | ≥ 7 (High Risk) | Multi agent chemotherapy: EMACO/Bagshaw regime • Etoposide, • Methotrexate, • Actinomycin D, • Cyclophosphamide, • Oncovin |
4: Other metastatic sites | _ | ‘’ |
- Mnemonic: 7 yr old (7-high risk) Emma (EMACO) Molkk (Molar prg) etomtop (Etoposide) actor (Actinomycin D) avan Cycle (Cyclophosphamide) vangi
- M/c mets → Lungs
- M/c chest X-ray finding
- Cannon ball appearance > Snow storm appearance.

WHO Scoring System
Feature | Low Risk | High Risk |
Age | <40 years | ≥40 years |
Antecedent Pregnancy | Molar pregnancy | Full term pregnancy |
Interval (Antecedent Px & GTN Dx) | <4 months | >12 months |
Prior Failed Therapy | ㅤ | + |
hCG Value before Rx | ≤10³ | ≥10⁵ |
Tumour Size | <3 cm | >5 cm |
Number of Metastases | <4 | >8 |
Site of Metastases | Lungs > vagina | Brain, liver |
History (4)
Investigation (1)
MRI + staging (3)
Cannon