Molar Pregnancy and Gestational Trophoblastic Disease - NEET PG OBGYN

Molar pregnancy is an important topic for the NEET PG exam because it is a rare but serious type of gestational trophoblastic disease (GTD) that can have significant implications for the health of the mother and the developing fetus. 

In the NEET PG exam, questions related to molar pregnancy can be included in the obstetrics and gynecology section and can test a candidate's knowledge and ability to diagnose and manage gestational trophoblastic diseases. 

Read this blog further to get a quick overview of this important obstetrics and gynecology topic for NEET PG exam preparation.

Normal Reproduction

Pathogenesis of molar pregnancy  

• Formation of partial mole: If Oocyte is fertilized by 2 sperms  

• Partial Mole
  • Fetus that is partly degenerated by vesicles.
  • It causes Choriocarcinoma in only 2-3% cases (almost not seen)
  • Better prognosis than complete mole.
  • It can also be, 69XXX (mainly), 69XYY, 69 XXY and can never be 69 YYY
• Complete mole

• It can be 46 XX (mainly), 46 XY and can never be 46 YY.
• The degenerated villi formation occurs: Start imbibing fluid and numerous vesicles appear
• There is 20% risk of choriocarcinoma.
• Aborts by itself (12- 16 week) 
• Difference between partial and complete mole

Presentation of complete mole 

• M / C: Bleeding 
• ↑↑ BP 
• Hyperthyroidism as HCG acts similar to TSH
• Rarely passage of grape like vesicles (rare) 
• Uterine size > POG 
• Hyperemesis (due to HCG ↑) 

Also Read: Endometriosis and Adenomyosis - NEET PG OBGYN

Mx of complete mole 

• Any size: Suction / Evacuation, followed by check curettage (after 1 week) because there might be retained bits 
• Chest X-ray because it is M / C site of Mets
• HCG values: Should be followed for at least 6 months after it comes negative 
  • HCG comes negative in 9 weeks: Complete mole 
  • HCG comes negative in 7 weeks: Partial mole 

Gestational Trophoblastic Neoplasia 

• Persistence of Trophoblastic tissue is confirmed by 
  • Continuous bleeding occurs 
  • High HCG >100000 
  • Persistently ↑↑ HCG ± 10% of previous value 
  • Bulky / Enlarged uterus 
• If there is confusion at HPE of Complete Mole or partial Mole: P57 KiP 2 immune staining is done; P57 in immune staining only seen with maternal contribution in the Karyotype, in partial mole
  • Complete mole will not show P57 KiP2 staining. 
• High Risk of Choriocarcinoma is seen with 
  • HCG > 10⁵
  • Very large uterus 
  • Theca Lutein cysts (high HCG) > 6cm size 

• Invasive mole
  • Does not follow normal pregnancy 
  • Marker: HCG 
  • Surgery is mainstay of treatment 
• Choriocarcinoma 
  • Marker: HCG 
  • Chemotherapy is treatment of choice 
  • For older women hysterectomy can be done
• Placental site trophoblastic tumor 
  • Marker: HPL (from cytotrophoblast, and its derivative intermediate trophoblast)
  • Hysterectomy is best management

Choriocarcinoma 

• WHO classification for risk assessment/prognosis

• WHO classification was used earlier, which includes blood groups also.
• But now it has been replaced by FIGO classification, which says blood group is not considered as a risk factor 
• FIGO Scoring

• Low Risk score <7
  • High Risk score ≥ 8
• Staging of trophoblastic Disease (Choriocarcinoma)

• MC site of metastasis is lungs 
• 2^nd MC site of metastasis: Vagina (sub urethral nodule): This appears as a bluish spot in the vaginal area and if you take biopsy of this area, severe hemorrhage can occur, which cannot be controlled by suturing & urgent Radiotherapy needs to be given to control it.

Also Read:

Vaginal Yeast Infections: Causes, Symptoms, Risk Factors, Diagnosis, Treatment and Complications

Postpartum Hemorrhage: Causes, Types and Management

Genital Warts: Causes, Symptoms, Risk Factors, Diagnosis, Treatment and Complications

Previous Year Questions

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